Dhru Purohit Show - Supercharge Your Sleep and Improve Your Longevity Using the Power of Intermittent Fasting & Circadian Biology (Rebroadcast)

Episode Date: March 5, 2025

This episode is brought to you by  Bon Charge and Momentous. We used to think circadian rhythm only applied to sleep. But emerging science has revealed a link between our circadian rhythm and metabolism, cognition, risk for chronic diseases, and many other crucial aspects of our health. Our biology was designed to live in sync with a natural light-dark cycle, but modern-day society has disrupted this natural balance.  Today on The Dhru Purohit Show, we’re revisiting one of our favorite episodes with Dr. Satchin Panda. Dr. Panda dives deep into his groundbreaking circadian biology research and shares how leveraging your circadian rhythm can dramatically improve your sleep, lower your risk of chronic disease, and improve your cognitive function. They also discuss how time-restricted eating, exercise, and light can be used to help program your circadian rhythm and why it’s especially important for shift workers to take advantage of these tools.  Dr. Panda is pioneering circadian biology research. He is a professor at the Salk Institute for Biological Studies, a Pew Biomedical Scholar, founder of the UC San Diego Center for Circadian Biology, and recipient of the Julie Martin Mid-Career Award in Aging Research. Dr. Panda has spoken at conferences around the world about his work on circadian rhythms and diabetes, including Diabetes UK, the American Diabetes Association, the Danish Diabetes Association, and the professional diabetes societies of Europe and Australia. In this episode, Dhru and Dr. Panda dive into: Why late-night eating is so detrimental to our health (2:15) Organ systems that have a circadian rhythm (8:24) Common ailments that could be related to circadian rhythm disturbances (14:11) Night-shift work and cancer risk (20:19) How poor sleep perpetuates bad food choices (27:00) What happens in the body when you rely on an alarm clock (44:01) Why you need to accumulate sleep debt for better sleep (51:25) Time-restricted eating and sleep (1:00:40) How to combat fragmented sleep (1:15:35) The best time to work out (1:55:50) The link between exercise and cancer (2:07:55) Positive changes for better sleep health on a global scale (2:17:20) Strategies for night-shift workers to combat circadian rhythm disruption 02:45:10) Dr. Panda’s research in firefighters (2:48:46) Tips for optimizing your circadian rhythm (3:14:20) Where to follow and support Dr. Panda's work (3:27:50) Also mentioned in this episode: The Circadian Code: Lose Weight, Supercharge Your Energy, and Transform Your Health from Morning to Midnight The Circadian Diabetes Code: Discover the Right Time to Eat, Sleep, and Exercise to Prevent and Reverse Prediabetes and Diabetes Download the MyCircadianClock app Try This: 6 Crazy Facts About Sleep Try This: How Exercise Helps Fight Cancer For more on Dr. Satchin Panda, follow him on Twitter @SatchinPanda, Instagram @satchin.panda, or his Website. This episode is brought to you by Bon Charge and Momentous. Right now, BON CHARGE is offering my community 15% off; just go to boncharge.com/DHRU and use coupon code DHRU to save 15%. Optimize your energy and mental clarity with the Momentous Three: Protein, Omega-3s, and Creatine made by and used by the best. Go to livemomentous.com and enter promo code DHRU to get 20% off any order.  Learn more about your ad choices. Visit megaphone.fm/adchoices

Dr. Such and Panda, welcome to the podcast. Pleasure to have you here. I want to jump right in. Tell us about why when we eat, which is the timing of when we decide to eat, the window, might be just as important, if not more important, than what we eat. Cicadian rhythm essentially relates to almost a daily timetable of things that has to happen in our body,

whether it is fighting immune, fighting infection, metabolic balance, brain health, or even repair and rejuvenation for injuries. And when we think about circadian rhythm, then since it's a big new concept, it's also a little bit difficult to understand, but just imagine that in our life, daily life, we organize our life around time. We think of the whole day, what time we have to get up, what time I have to go to school or send kids to school, and then what time I have to go. go to work, what we do, and then in the evening, what time I have to meet friends or get back to home, what time we sleep.

So similarly, every single cell in our body has its own 24 hours timetable. That means the cell has to decide, okay, this is the time I have to make energy, this is the time when I have to recycle. This is a time to divide and rejuvenate. So this is a very new concept of science, and this has the potential. to impact our daily habits, and it has the potential to increase efficacy of medications that we take or supplements that we take on a daily basis. And also what we're seeing now, there are also new drugs that are based on circadian rhythm to essentially based on the idea that as we get older or in many diseases, our circadian clocks are disrupted. And the question is, if we can fix our clock with a new drug,

can we also fix a disease? So these are three big principles that are coming into play. And you mention time-restricted eating, intermittent fasting. That's kind of one aspect of this circadian rhythm biology. But this is actually one way to get into the science, because once we understand why we should be eating in less than 12 hours and why that has to be consistent, what is the science behind it, then we can dissect a little more into the interrelated parts of fasting, sleep,

what time we should be exposed to light, when we should exercise. And that will give us kind of a nice toolbox for each one of us to adopt. Absolutely. So what I'm hearing you say is big picture, the most important thing to understand. And it has all sorts of applications, including when to eat, when to sleep, when to be active, when to potentially take a drug, as you mentioned. People are on pharmaceutical interventions. So it's most efficacious and effective for the body.

But first, we didn't understand that not just our entire body has a circadian rhythm, which I think most people who are listening today know, but different organ systems also have their own biological clock. Give us an understanding a little bit, for example, of an organ system or cells inside of the body that have their own individual rhythm that many people may not necessarily know about. Yeah. So let's start with what we do every day.

Eat. So when we eat, our digestive system digest it. The food, adjures the nutrients, sensitive blood, and then our pancreas does its duty to control blood glucose. So now if we start with digestion process itself, the first stage of digestion is that happens in our mouth, As we salivate, there are many enzymes in our saliva that breaks down some of the food components. And there is a circadian rhythm to this whole process of salivating.

And we are more likely to produce a lot of saliva during our wakeful hours or during the daytime. And the saliva production actually goes down, way down, right around when you go to bed. And I'll get to that point why this plays a role. So now the next step is digestion, and that happens in the stomach, and a lot of the enzymes that break down food that are produced in what we call the pancreas. It has two different roles. We always hear about the insulin production part, but pancreas also produces a lot of stuff to digest our food.

And then what we now know is that that process, producing acid to break down food and these enzymes to break down the food. All those are also circadian. So that means during the daytime, there is strong production of these enzymes and increased acidity to break down food. And then there is a weird thing that happens around sleep time or late at night. Our stomach is more sensitive. So that means even a little amount of food can hyper.

it's almost like the stomach is sleeping and all of a sudden somebody comes and knocks on the door and not only you wake up, you actually wake up with increased vigilance. You may pick up a stick or something thinking that somebody is invading. So stomach actually hyper reacts by producing too much acid. And now too much acid is actually not that bad. But what happens is too much acid can go up ostefagas and can come. because acid reflux. And I told you that how at nighttime,

our mouth actually reduces saliva production. The reason is in our sleep, we should not be drowning in our saliva. So saliva neutralizes a lot of acid. So then we have increased acid production at night and less saliva to neutralize it. And that's one reason why people eat too late at night, not all, some might actually experience more acid reflux than other.

So now, in the next step in digestion is after this stomach is digesting food, it goes to the intestine, and the intestine kind of has a peristaltic motion. So that means it beats and sends that food slowly while the intestine is also absorbing nutrient. And that process almost shuts down during our sleep or late at night. So that means even if you have eaten food, it actually doesn't get digested, the nutrient doesn't get absorbed later night. So this is a clear example how even very basic step of digestion has a strong circadian rhythm, and that helps to make sure that our food is digested the right way. And the reason why everything starts down in the digestion at night is during the daytime or when we eat,

just imagine it's a, it takes a lot of. of energy, a lot of acid to break down food. Imagine kind of digesting that piece of sushi that you ate. So if your stomach is digesting that piece of sushi, at the same time, it must be damaging some stomach lining. And that actually happens. So that stomach lining has to be repaired at night. So there is a different circadian rhythm, starting from the brain, that produces growth hormone in the first couple of hours of her sleep. And all the although we are not growing after reaching adulthood in size or height, but actually we are replacing many of our stomach lining and many other cells throughout the body.

And that happens only at nighttime. So again, there is another clock that kind of works with the digestion clock to make sure that during daytime we digest and at nighttime we repair. So these are just very few examples. but if we drill down almost every single cell has its own clock and it has implications for how we should live, how we should organize our day around these clocks. Yeah, it's really fascinating. You know, when you really get a chance to zoom out, we see that the world and the way that nature was set up,

including the 24-hour cycle of the sun and how it interacts, depending on where you live in the body, the sun rising and setting, that was the foundation of what our biology evolved around. Yeah. And now through modern living, we're able to eat later, we're able to microwave foods later, we're able to get processed foods later. And a lot of these foods are way more addictive than they ever were. Hyper palatable, I guess is the right word. So we're in a situation where we can see now through your example that just by regularly

eating late or late at night or right before bed or midnight snacking, as many people do, we can now see that things like acid reflux in your example, why they could be so prevalent among society, right? What would be another example that's tied to late night eating? Common things that you see that people are struggling within their body that they may not understand has to do with circadian biology. So one is acid reflux. Another one could be waking up and not feeling rested.

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Yeah, so, you know, acid reflux and indigestion, another thing we talked about. And again, going back to the same digestion process, one more thing is, you know, when we eat something, most of our food does have some carbohydrate, unless you are just eating ketogenic diet, which is very difficult to do for long term. But for every regular person, we consume some carbohydrate. That means that's broken down and that increases blood sugar level and the pancreas has to adjust that sugar by producing insulin. And pancreas does have a circadian clock. So that means it actually doesn't produce enough insulin late at night.

So that's one. And then the second thing is the sleep hormone melatonin that goes up in night. And that's why people who have sleep problem, they think that they can sleep well by taking extra memory. And I'll get to that, but the melatonin actually has another break on insulin production because melatonin makes the pancreas less sensitive to glucose level in our blood. So the pancreas cannot sense accurately how much glucose is in the blood, so it cannot produce or release enough insulin. So now you combine these two.

What happens is when we eat late at night or very close to bedtime, then there are at least two or maybe even more things that are playing against digesting and absorbing that glucose correctly. One is insulin production itself has slowed down. And second, if there is melatonin that's rising, and actually two hours to three hours before our habitual bedtime, our pineal gland starts to produce melatonin. So that means within two to three hours before bedtime, if we eat, then we, then that melatonin can inhibit, can desensitize the pancreas so that it's not producing enough

insulin. So these two can work together to first thing that will happen is you might have higher level of blood glucose level. And this is something that has been observed since 1970s. Even, in fact, endocrinologist would take healthy people and fast them for 10 to 12 hours and then give them a bolus of glucose either in the morning or after 10 to 12 hours of fasting, the same bolus of glucose or sugar in the evening. What they found was the same healthy person may be diagnosed healthy in the morning,

but may be diagnosed as diabetic because this person's blood glucose goes pretty high and doesn't come down easily. So this is another example where people who are thinking that they can get away with food at night, although we are not walking around with continuous glucose monitor all of us, but some of them.

And this is a common theme that we are finding. The third thing that happens is just to make sure I understood that correctly, and you're kind of recapping for our audience, so that regular, we're not talking about occasionally people eating, and the tendency is that at late night, people want highly pot, palatable, salty,

sugary types things. They want chips, which again are types of foods that, again, that are not, you know, the ketogenic route, right? Yeah, yeah. They contain a lot of starches. Starches are broken down as sugars inside your body. Yeah. And not only are you inhibiting your melatonin production, which is going to throw off your sleep,

you're also keeping your blood glucose. Yeah. Around higher longer. Yeah. Which has all sorts of downstream effects. Yeah. And also since it's the time when insulin production, it's not that insulin production has shut down.

It's actually there is a trickle of insulin. that comes out and it continues for a long time because it has to work hard to get the glucose absorbed. So then your insulin level remains high in the blood for a long time. And that has a lot of other effects because insulin also promotes fat making. So our cells actually make more fat also in response to insulin. So that's another reason why late night eating can cause weight gain. Chronic late night eating.

Chronic late night eating. Even if the calories are the same, chronic late night eating could be or is. Is it could or is contributing to weight gain? Yeah. So this is something that has to come from clinical studies. Yes. But at least in mice or in laboratory animals where we can accurately control what time they're eating, how much they're eating, what quality of food they're eating. There we can see that when they eat random.

or eat when they're supposed to sleep, then they gain excess body weight. Yeah. It's so fascinating because then it also helps many people understand how they feel like they're caught in a vicious cycle. Yeah. Because when you eat late at night and your glucose stays up and your insulin stays up, again, chronically, we're not talking about the one or two times that people do that occasionally just to live your normal life that you're doing.

You end up in a place where so many things are disrupted and your metabolic health, but then also that leaves you in the morning because your sleep is disruptive that you're more likely to have cravings for sugary, hyper-palatable foods the next day in addition to just feeling not 100%. No, that's true. I mean, a lot of people we think that we can get away with occasional late-night eating. And this is where the circadian rhythm, again, some of the concepts of cicadian rhythm kicks in. When we think about what are the adverse effect of disrupting our rhythm, we always think of people who do night shift work, evening shift work, or morning shift work.

And there is a rich literature from over the last hundred years. People have gathered a lot of literature. So seeing that many people who work late at night or night shift workers, they are actually at a very high risk for metabolic disease, cardiovascular disease, heart disease, etc. Cancer as well. Cancer also. I think I read somewhere that Denmark now will provide extra compensation for shift workers who are diagnosed with cancer. Yeah. Because there's so much literature that's there with the association of shift work and cancer.

But I think what is actually disconnected, what we don't understand in real life is if we ask what is shift work, one, I mean, it's not that. Please break it down. Yeah, it's not that. Somebody who has, somebody has to have a job, like in police department or firefighters or nurses. Of course, they are shift workers. Right. But then if we think about metabolically for our health, for our body, how our body is thinking whether you're doing shift work or not, because our body is actually not checking whether you checked in to your shift work or not. It's only checking two things.

Are you staying awake for two or more hours between 10 p.m. and 5m. because that's when your body is designed to sleep. So are you up for two or more hours between 10 p.m. and 5 a.m. And 5 a.m. And being engaged in some kind of work. It's not that you're not just lying in bed with your eyes open. Of course, if your eyes are open and you're watching TV, that's also. Sure. Watching TV or if you're on your mobile phone. Yeah. That's also work as far as your body's because your body is not resting. And so, and if you do that, on an average, once or twice a week. That is shift work because your habitual sleep time,

suppose say, is 11 o'clock every night. And once or twice, you are staying awake either till 1 o'clock in the morning or you are waking up at 3 or 4 o'clock in the morning to get to work or do something. Now, if we think about it, almost 70, 80% of us are shift worker. Or we are living the life of a shift worker.

So if you look at the average person who's listening today, because they're disrupted at least a couple times a week, they're looking at their phone, they're up for a couple hours, they can't go back to sleep. Essentially, they're a shift worker. They are a shift worker. And if you think about now,

let's become more granular. So who are at a high risk for this kind of disruption? All the high school students. because over the last few years of the pandemic, what has happened is there is a lot of remote learning and then the default time to submit your homework is now midnight. And then the same thing applies to all the college students. So starting from teeners, now we have literally institutionalized

circadian disruption by making your homework some mission time as midnight. Right. Then let's think about after young adults go and get a job in many jobs. Of course, they're staying up late or they're traveling. But let's think about women. In this country, in the U.S., every year, 3.8 million women are becoming new mom. When they're becoming new mom, they're actually signing up for shift work because they have to wake up many times in the night and they have to take care of the babies.

Right. Breast feed, bottle feed, change diapers, everything. What is worse is shift workers actually get days off. But new moms don't get days off. They don't, right. And then we have to also think about caregivers. There are a lot of us who actually give care to parents or somebody who is sick at home. Sometimes there are people living with chronic disease with us.

And those caregivers also have to stay awake. So in a way, that's why I'm saying, like more than 70, 80% of us live the life of a shift worker for at least one to two years in our lifetime. And we can all relate that whenever we live that lifestyle, we're not actually living with our peak performance. We are not living with our big physical, emotional, and intellectual performance. We don't feel good. People are gaining weight. They're not clear. they feel hangary or irritable.

And then on top of that, if we look at the trends, which I'm not saying is directly associated, but just the correlation, chronic disease is up, all sorts of markers of cognitive decline are up, and not all linked to sleep, but sleep is a crucial part of it.

Is that part of what I'm hearing you say? Yeah, sleep is a crucial part of it and also sleep. When you disrupt, it's not like we are actually not sleeping and not eating, Because when we don't sleep, we also tend to eat more. Right. So, as you mentioned, when we don't sleep, actually sleep has many functions.

And one function is to make sure that our literally our mind is clear because when we sleep, our brain actually gets rid of a lot of toxic products. Yes. And literally sleeping is declottering or detoxifying our brain so that our mind is clear. And why this is important is different parts of our brain has to, they have to interact with each other. And they have to be clear communication between brain parts. And why that is important is our brain essentially does few things. One is it takes information correctly.

Second, it processes that information. And third, it takes action. So just now, as we're talking, our brain, our listeners, brain is taking that information and sometimes it's processing it and then that may be converting to action. But in real life, in every day, we are also making a lot of decisions. So, for example, you walk into a store to pick up your coffee and you're seeing a lot of food choices in front of you and your brain has to take that information and process and decide what you're going to order or what you're going to eat. You are walking into your kitchen. So should I get the donut?

Or should I eat the vegetables? Yeah. And even if you had promised last night that you will eat healthy because of sleep deprivation, now the brand is making a lot of bad decisions. I'll say, oh, maybe you, just one day, just this time. I've been good all week or, you know, I worked out earlier. Just one donut is not going to be a problem. Yeah.

Right? We justify things to ourselves. So that's why you get into this vicious cycle, that your sleep is disrupted. and you make bad food choices, and then bad food choices will also perpetuate that habit because this highly processed food also give you glucose spike, and then you go into the low, and then you have to compensate for that by drinking coffee to come back to full energy. And then when this continues throughout the day, then you have late-night coffee intake, and that disrupts again another night of sleep, and it continues.

Right. So now the point is, you know, we designed this anthropogenic world or the man-made world over the last 150 years of post-industrial era without knowing how important is this circadian rhythm. So it's almost like building all our buildings with lead and asbestos that we did up to 1970s. Sure. Without knowing what are the harmful effects of those bad things. And now we are trying to clean up that. Similarly, this is a point only in the last 20, 25 years, we have begun to understand what is the role of this circadian rhythm, 24-hour rhythm, and when we disrupt these rhythms,

what happens? So I think this is, we are just at the beginning of understanding how these rhythms affect so that we can redesign our world. It's not that we have to switch off our light. in the evening and then go to bed every night at 10 o'clock and wake up at 5 or 6. But the challenge is how do we understand circadian rhythm in a way that we can still continue to perform at our peak physical, emotional, intellectual performance at any age and at any health condition and still continue to be healthy.

That's the big challenge. It's a powerful mission, vision, and obviously your work has been at the forefront of it just to put a little bow tie on the topic of sleep and then we'll come back to later on would you say that and you've been hearing this more and more but i'd like your opinion would you say that investing in improving your sleep your sleep hygiene which is also tied into not chronically eating late at night or allowing at least a little preview of some of the recommendations like three hours or so of not eating before bed would you feel that the vast majority of people would see a significant improvement in their life just by focusing on that.

You know, everybody's trying to balance out. What should they do? Should they do this? Should they focus on this area? Should they focus on that? And sometimes people are so caught up in eating the perfect diet. And there is no perfect diet that's always going to modify for different people. But what is there is that generally we all have the same circadian biology with some variances that are there. So for most people, if they're sleeping, is thrown off regularly by eating late, just by focusing on that, they're going to see a big difference in their health. Is that an okay statement for me to make? You know, in a perfect world, we would all get enough of the nutrients that we need for high-level

performance from our diets alone. That's in a perfect world. But we live in the real world, and that's a world of nutritional deficiencies and not always optimized diets. And the truth is that every single one of us could use a little bit of support when it comes to the path of becoming our personal best every day. For me personally, as I always talk about on this podcast, the first step is nailing the basics. That's why I love and start with the Momentus 3. It's protein, creatine, and omega 3 supplements. These are the three nutrients that expert research shows as the foundation of long-term health. And taken daily, this protocol supports every cellular function in the body and the brain. From muscle recovery and growth to focus in energy, the Momentus 3 is the easiest way

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Yeah, I mean, when we think about lifestyle, when we say, what is your lifestyle? We always talk about how lifestyle affects health. And what I say, lifestyle is what, when, and how much, we eat, sleep, and move around, or physically active. So out of these three, for eating and for moving, you have to actually make a conscious effort and you have to invest. For example, for eating, you have to invest in good food and all that stuff. And then for exercise, also you're reinvest.

Sleep is the simplest one. You don't have to do anything. You just have to go have a set time when you have to go to bed and just lie down. And that's the simplest thing out of all these three that one has to do. And it's just mind-boggling. Why so many people just can't get that one correct? because once you get seven hours of restorative sleep, then everything else falls into place.

Well, you alluded to it earlier, and especially for young people, there's so many distractions that we have to battle against. So it seems so simple on the outside, this idea of, hey, get seven hours of uninterrupted sleep. Yeah. And we are facing all these challenges, distractions, Wi-Fi, mobile phones.

And so in a way, we have to take something that came so now, naturally to us as human beings. And now we have to become a lot more intentional. Yeah. I mean, this is, there's also another twist to that. Because, you know, after the, we humans are the only species that can control fire. That's the differentiator.

It means no other species can control fire. So that means we also control light. We also control warmth. And if you look at last 150 years of human history, human civilization, our civilization actually flourished by being active late into the night. Right. So that means when we are active late into the night, sacrificing some amount of sleep, then we can create wealth.

We can be more creative. We can make a career. And that's what has percolated down. to students, high school students, college students, and we always demand that they, even for many families, they say sleep is not that important, just get four to five hours of sleep and then get back, do your homework and all that stuff. So but then the question is, can we show benefit, tangible benefit, by letting students or teenagers sleep?

And this is where science comes into place. So, for example, a few years ago, Horacio de la Iglesia, who is a professor in U.D.D.O. University of Washington, did a very fundamental study. What he found was, well, most people, most parents who have high school or they know that the high school students, they wake up just before the class begins, and then you have to drag them to school. They're sleepy, and then for the rest of the day, means they wake up after midday. So then the question is, if you delay the high school start time, hopefully you can give them opportunity to sleep a little bit more. So this is a study that for us, you took great pain in convincing a couple of schools and then also the Seattle School District to experimentally delay high school start time by just an hour. And has he reported the findings? Yeah, so that was actually published in 2017, 2018.

So there are two different schools. This is where we talk a lot about scientific results and how the lifestyle and everything is built on scientific evidence, but it takes a lot of pain and a lot of organizational skill to get this simple study done. And there was also a lot of opposition because the parents said, well, if you delay the high school start time, then maybe we cannot drop them in the right time. Right. I have to be at work at this time.

Yeah. And then the school buses, the driver said, no, it's kind of. breaks our schedule. So it took a huge amount of planning to do this study, and this was only two different schools. And also he had to make sure that you just can't do it in one school because every school has a different demographic. People, students have different socioeconomic status also come in. So he had to do it in two different schools, one relatively rich neighborhood and one not so rich neverhood. And for one year, these students actually delayed their school start time. And then he had to follow them. So he had to collect, actually,

objectively collect how much activity, how much sleep these kids had by putting a active watch or FDA approved fitbit kind of device. And that also collected their light exposure, their physical activity, their sleep. And then not only that, he had to also collect how they were doing at school. So then he had to get access to grades. And, you have to get access to grades. And tardiness, whether the students are actually getting late to school or early to school. The bottom line is what we found was by delaying high school start time by an hour, these two school students got to sleep 34 minutes extra. And what do you think about?

So what, 34 minutes? Actually, the best sleeping pill gives you only 15 to 20 minutes extra sleep. So this was, the outcome was actually much better than the best sleeping pill. Which is what Ambien is that people take something? On an average, I'm saying. On average. And then second thing is, sleeping pill will not improve grades. These kids actually improve their grades by 4.5%.

In both schools. In both schools. And then the third one actually reduced their tardiness. And when they're not getting late to the school and their own time, it also improved their self-confidence. And for many high school kids, it's a big thing, how to feel confident, to have that self-immiss that they're worth it. And those things actually improved.

So those were published, and then there are many other studies similar to that. Those are repeated in different parts of the U.S. and Europe. And that finally led to California legislature to pass this delay school start time bill, and so that now all California schools, middle schools and high schools cannot start before 8.30 in the morning. So this is another example where, you know, circadian rhythm research can actually lead to public policy changes. And this is one example where we did not know what is the impact of circadian rhythm or sleep on students' performance. And we designed school start time without paying attention to the importance of sleep in circadian rhythm. And now that we know what is the impact and we change school start time, now we are

delaying, now we are letting students sleep much more than what they could have slept with a sleeping pill. No, that's powerful. This is powerful. What was this researcher's name? Horacea Deliae Glacia. Amazing, amazing. And actually, I was fortunate enough to be a co-author because we analyzed a lot of the

data from that study. And then we have continued to collaborate on many other aspects. This is, again, some of the studies that are not easily federally funded. Sure. And these are the studies that are mostly done by initial, like, a little bit of contribution from philanthropy. Private philanthropy. And when you think about private philanthropy, we always think of Bill Gates and, you know,

Chan Jukabargo, we're putting billions of the dollars into it. Right. We think of the mega-millionaires, and billionaires who are funding things. Yeah, but actually some of these studies are done with small contributions from people. So that's why just think about it. If a million people just donate their one cup of coffee worth of money to a lab, we're talking about $2 to $3 million. Absolutely. Just a million people, one coffee cup.

And that will do a huge amount of research because a typical large federal grant is about that size. And there is also a reason why we should not play with honest taxpayers or federal money on random ideas because sometimes these ideas are very out of the box. They're bold ideas. They may not work, but if they do, they can have big implications. Yeah. So that's why the research enterprise also works in a very systematic way. First, we try to do small studies in, say, animals. And whereas where we work with, say, fruit flies.

little bit of cells and a disk and then we play with that idea to see whether it actually has some benefit also whether it has some risk because sometimes some ideas can actually kill fruit flies but we should not play with that idea on humans so we produce that initial idea testing and for that we need this philanthropy money or private donations because this is where we I personally don't want to use honest taxpayers money. When we think about federal money, we are thinking about, okay, some federal government writing a check. No, actually that money comes from people who are taxpayers. And it's great that we have the NIH and we have that.

But often the funding that can come from there might be at the end stage of research that people are working on, that it's the last little bit. For some of these bolder ideas, it could be a little bit tougher to get funding. Yeah. But that's actually what a lot of people, and I know that's why. what I'm interested in on this podcast. I mean, it'd be great for somebody to solve. Who knows, maybe I might get involved with somebody who's working on it, like a GoFundMe type

thing for researchers. Yeah. And then maybe even having people like, I don't know what should be funded and what should not be funded, but I'd love to have somebody like Dr. Ronda Patrick or Andrew Huberman or other individuals saying, hey, look, pay attention to these, you know, few things. I know Tim Ferriss has done that a little bit. Yeah, yeah, yeah. Sillacin research and plant medicine that's there.

Something like that would be amazing. Yeah. So people could participate. Yeah, so people can. But in the meantime, if you look around, even labs like your own, you guys do accept donations? Yeah, we do. Actually, we'll have the link to our labs donation phase. And this is where even small donations actually have because sometimes the trainees, the

PSD students and then postdocs who have finished their PSD who could have gone to make big box in the pharma or in other places. They're actually passionate about research. they're working and then, you know, sometimes they want to go to a conference to present their results. Sometimes they want to just have subscription to a journal. There's only a few hundred dollars. So these are really some of the key contributions. And as I said, long time ago, when we started this time restricted feeding or time restating, which is now famous as intermittent fasting, there was all funded by small philanthropic grant. And if we think about, okay, what are the

turn on investment on those philanthropic grants. It's 100 times, 200 times. Yeah, because now this idea of time-restricted eating is out there in the zeitgeist. And I know many, many people who feel like they've improved their body composition, lost weight, feel better, sleep better, because they've been able to practice that. But the research had to be shown for the newspapers and everything else to pick it up, for book deals to happen, et cetera.

So, I mean, it's an incredible return on investment for the lab that you, for the people that have helped fund that research. Yeah. So let's get back to. Yeah, let's get back to that. But that was a good little tangent. I'm going to be the first to donate after this podcast is done. I want to come back to sleep for a second.

You know, you've shared something very important, which is, you know, you're not against alarm clocks, but you just want people to understand what happens when you consistently have to wake up from an alarm clock, right? So what's happening to the body when you're reliant on waking up from an alarm clock? And could there be a different way of going about things? So I'd love for you to chime in about that. Yeah, so a lot of us actually, we wake up to an alarm clock. The reason is a body is not prepared to wake up, and we're forcing our body to wake up. And the reason why our body is not prepared to wake up is we may not be getting the amount of sleep that our body needs.

So, for example, most people say that, okay, so you should get seven hours of sleep. But in fact, if we look at teenagers, teenagers need eight to nine. hours of sleep and as we get older we think that we actually need less sleep because our grandparents or our parents may be sleeping less but it's not that the need less sleep they just can't sleep because their sleep debt will get to that sleep that doesn't add up so their body doesn't feel sleep dead yeah yeah so so now let's see why we wake up to alarm clock and what happens so approximately one to two hours before we wake up, there are many things that happen in our body and brain to prepare us to wake up.

One of the things is our melatonin production goes down because melatonin helps us sleep and it has to go down so that we can wake up and will feel a lot. Then our blood pressure slightly increases, our heart rate also slightly increases, our breathing increases so that we can, when we wake up we have breathing enough oxygen. Our heart is pumping enough so that we can actually move around without feeling drowsy and our brain is also waking up. So when we said that alarm clock and we wake up, yes, we dragged ourselves out of the bed, but our circadian rhythm hasn't prepared our body to wake up. So the hormones of the day, nighttime, they haven't gone down. So for example, cortisol, sorry, melatonin levels haven't gone down. Our heart hasn't started to, pumping at its usual morning rate and our breathing may be slow and all these things happen.

So that's why if you can, the first thing that you can do for the day is go to bed at a consistent time and stay in bed for at least eight hours so that you can get seven to seven and half hours of sleep. And when you wake up with little bit of nudge from alarm clocks, just a reminder. Sometimes some people actually use the alarm clocks just to remind them that, hey, this is, usual wake-up time and they can get out of bed. But most people actually put an alarm clock so that they can drag themselves. Right. And second thing is you have to acknowledge that if you have to wake up to an alarm clock, because you are sleep deprived, you just cannot get enough sleep. Because, you know, there are many people who are morning shift workers or they have long commute

hours, so they have to get up. Then you have to be mindful that our body is not ready for a few things. One is your body is not actually ready to eat after you wake up because your nightly hormone melatonin is still high and your stomach and digestive system has not become ready to digest and process that food. So in those cases, you definitely should not be eating right away after waking up. And then another thing that I think is not well researched is whether you should actually do strain of exercise in the morning, if you're waking up to an alarm clock, if you didn't have enough sleep, suppose, say, you had only four or five hours of sleep, but your routine is go to the gym in the morning. Should you actually go to the gym? And if you go to the gym, what kind of

exercise you should be doing? Because your heart is not running at its peak performance. So what people have seen, and this is again, this is an experiment that has been going on for hundred years. That is. Since the modern industrial age. And the experiment is the, you know, the standard time and the daylight saving time. Right. And light bulbs.

No, particularly when we fall back and they fall. Right, right, right. So then everybody is. Daylight savings. Daylight savings. And then when it ends, everybody has to wake up an hour early. Right. And what we have seen is that that's an experiment where millions of people.

people have to essentially set an alarm clock and wake up an hour earlier than they're supposed to. And then what happens? That's the morning when there is a spike in heart attack and stroke. And that essentially says that what happens when you wake up an hour earlier and then go do your regular stuff. And of course, it's not that all healthy people, if they wake up to an alarm clock, they will get a heart attack. But it says that, okay, so for a lot of people, for a lot of people, you know, for a lot of lot of people who are not whose heart is not ready or who may have a weaker heart or there

might be an underlying condition than just working up to an alarm clock can put a lot of stress and you should be mindful of that stress by not engaging in strong stress stress stress physical activity resistance straining lifting a lot of weight all that stuff so this is another example why how circadian rhythm knowledge can help us optimize by adjusting our morning routine when you have to wake up to an alarm clock. No, it's very powerful. I mean, the takeaway for me is that if you are relying on an alarm clock, okay, there could be a lot of reasons.

Don't freak out. And that's the perfect sign that if you can, and people are in plenty different situations, obviously there are situations that you can't control, like having a new child. Yeah. You're talking about young moms, young dads. And, but if you can invest in going to sleep earlier.

and being more stringent with your routine. That's pre-sleep, including light, which we're going to chat about next, so that we can be designed to, as long as you're not a morning shift worker, which might be a little bit different. That's a lot of caveats. But if you are lucky enough and privileged enough to have a normal work schedule that's there, generally you should be able to wake up on your own at a time that's appropriate, but that only can happen without an alarm clock if you're getting enough sleep.

Yeah, if you're getting enough sleep. If you're getting enough. That's a big challenge for a lot of us. It's a big challenge, but it's well worth it. Yeah. Because it has so many implications in so many different aspects of our metabolic health, chronic disease, diabetes, cancer, etc. And as we said before, for a lot of people, they would see a massive improvement in their health,

especially as they age, if they just paid a little bit more attention to their sleep. Yeah. And particularly, you know, when you are talking about sleep, we're always thinking about metabolic health and age. But we should start that practice when, you know, our kids are going to middle school and high school. Because that's the time when sleep disruption begins at that stage. Because that's the time when we put a lot of pressure on our kids. And also the kids are also feeling pressured by their peer to stay up late into the night. And they lose sleep.

And when they lose sleep, then that increases the risk for anxiety, depression, bipolar, and all these brain health issues that we are witnessing. And this has become a pandemic because, you know, some of the surveys that you see, we see that one in five high school students are so depressed that they thought about suicide. Those kind of numbers or how what fraction of college students are actually seeking mental health help. But we don't talk about how to structure high school, college, and then in a way that kids can actually get sleep that they really deserve. Means if we want to invest in kids' future, one investment, one thing that we can do is let them sleep for at least seven hours. If we think about, if we look at high school students, 90 plus percent of high school students do not get the amount of sleep, the body, needs. The same thing applies to college students. And when they don't sleep, they can counter it with, so one thing is there is mental health issues and sometimes there is also substance abuse

issues that come from reduced sleep. So we have to think about the whole spectrum from high school kids, all the middle school kids, all the way to older adults. You mentioned sleep debt. Yeah. Talk to us about sleep debt, how it accumulates. And if people are listening to you, today and they have sleep dead as you after you describe it what can we begin to do is it again doubling down and making sleep a priority so let's chat about a big picture what is sleep dead well well sleep that is our body needs says for example seven hours of sleep because a lot of studies around the world when they look at what is the average number of hours people sleep and what are the comorbidities or diseases or even longevity what they find is six and a half to seven and

half hours in adults, older adults, we're not talking about college students or high school friends, older adults. That seems to be the sweet spot. People who sleep less, they have more comorbidities and people who also sleep more. Maybe they have underlying conditions. That's why they're sleeping more. They also have other comorbidities. Right. You don't want to be sleeping nine hours plus if you're not an adolescent, right? Yeah. Yeah. That's a sign that maybe something's going on, chronic fatigue, et cetera. Yeah. You want to hit that sweet spot of those seven to eight hours. Yeah. So, A lot of people who sleep less in the weekdays, say five to six hours or five hours, then they experience it, that their body actually keeps track of how many hours of sleep you have lost.

So that by Friday or Saturday, you are so sleepy that you just want to catch up. When people say, I'm catching up on my sleep, that's exactly what they're doing. Their body has calculated and is telling them that, okay, so on Saturday, you got to sleep another four hours or five hours. and they're catching up. And what happens is, so that's kind of what we say sleep debt. You have taken that debt against your regular sleep

and you have to pay it back, pay it back to your body by sleeping extra. When we get older, then what happens is a body's the sleep debt calculator doesn't work very well. It actually doesn't remember

how much debt we are accumulating. So that means you can go with less sleep, four or five days, but your brain is not remembering, so you'll still end up sleeping less. And you think you're fine. And you think you're fine. So that's why this is some instances where you should not be listening to your body. If you know, if your smart watch or smartphone is telling you, you have been sleeping for five hours, and you know that you are sleeping for five hours every night, and then you got to work on it. Another reason why we also forget our body,

forget sleep date, is when we over-consume caffeine. And this is something I have personally felt because, you know, and there are many times when I have to consume excess caffeine or maybe late afternoon coffee just to get through a grant deadline or manuscript deadline or something else. And then if I continue that, have it in the weekend and also have a lot of caffeine, then of course I'm sleeping less six or less hours. And my brain doesn't remember that, that I am having sleep dead. But the other way it shows up is I'm more hungry, I'm more irritable. I know that I cannot think clearly. And my overall productivity goes down.

And I'm kind of struggling. And then I kind of blame myself. I blame people around me. And I'm thinking that, okay, so for all of my problems, somebody else is responsible. I bit myself, why I cannot get these things done. So a few years ago, I did a simple experiment. I kind of do all types of experiments on myself. One is, I said, okay, so between Thanksgiving and New Year, I will stop caffeine,

all kind of caffeine-containing drinks. Coffee, green tea, et cetera. tea, Diet Coke, or anything that has coffee or caffeine, including, you know, dark chocolate also has many flavonores that can keep us awake. And to my surprise, almost every night, the first few days I felt like I haven't slept for a month or so. My sleep there just kicked back in. And then I would fall so sleepy.

I would feel so sleepy by a nano clock. It was really hard to stay awake past 9.30. And so that goes on for at least 15 days to three weeks that I'm just sleeping like eight, nine hours. Because you don't have caffeine, you feel more sleepies. Yeah, I mean, my body actually has remembered my sleep debt. And it's just saying, no, you got to pay. You have a huge debt. And you haven't paid for a long time.

And then after two to three weeks, then I come to the equilibrium that I can actually sleep for seven hours. And that's when I realized, okay, so this is my normal circadian rhythm. This is your baseline. This is my baseline. That's you want to do a little bit of a caffeine cleanse to reestablish that. To reestablish that. To reestablish it. And also to know what my body needs.

And essentially what my body needs is I should be going to bed between 10 and 11 and should be waking up between six and seven. That's what I figured out. So this is the kind of stuff that everybody can do once in a while, do an experiment. You're not going to die if you stay away from caffeine for. Maybe in the weekend or for a week. And we always talk about personalized health, personalized pre-season health and all these fancy terms that we say. Whenever that is the word personalized, we have to keep in mind that more than half of that responsibility is on us to try something, a new lifestyle. Try to figure out whether you can change the quality, quantity, or timing of your food, exercise, or sleep.

And this is where one can actually try. And for older adults, it's difficult because, as I said, even in experimental models, like, for example, we can take little fruit flies. And this is not experiment in my lab, but other people have shown it. And the young fruit fly, if you keep them awake by putting them in a rotating drum so that they cannot sleep, then the next day when you give them an opportunity, they will sleep. but you take the older fruit flies and keep them awake. And next day, they actually don't fully compensate their sleep loss. So this is a phenomena that's already known, happens in humans.

So then the question is, can we model it in flies or drosophila fruit flies or in mice? Then we can go back and see, okay, so what part of the brain is involved? What can we do for the fruit fly or the mice to remember their sleep dead? that they can go back to sleep and recover. And then what happens when they have this sleep date, when they cannot sleep enough? So, for example, now many labs have shown that in experimental condition, if you take a mouse or a fruit fly that is prone to neurodegenerative disease

or dementia and you disturb their sleep for a few days, then that can accelerate the progression to dementia or that can exacerbate the symptoms, of dementia. And so that's one part of this story. And then the other part of the story, which relates to timing of food, is if you now put these fruit flies or mice that are more prone to dementia, and people, we never connect how timing of food connects with dementia, but this is something that actually one of the earliest experiment was, in fact, done in L.A., in Los Angeles, in UCLA.

At the Buck Institute? No, actually UCLA. UCLA. UCLA, yeah. And what they did was they took a few mouse strands that are more prone to Huntington disease, and they did eight hours time restricted feeding. So that means these mice have to eat only for eight hours and fast for 16 hours. And what they found was surprisingly the sleep quality of these mice actually improved.

And I remember that experiment because, the researcher and their team actually asked me, hey, do you think there'll be an effect? And those are the early days, 10 years ago, nine years ago. I was thinking, huh, this will be an interesting experiment to do. Let's try it. He tried it. And we found that.

And then now there are a lot of studies on how time-restricted feeding or intermittent fasting actually helps brain health by improving sleep. And this is something that we had never thought so just by narrowing that window yeah not eating late right which we were talking about earlier yeah which typically is going to mean that if a lot of people are falling to sleep at 10 yeah you're done eating by about seven six or seven because you want those three hours that are there again that goes into the all the circadian biology of the organ systems everything like that but you're also saying that in addition to not keeping your you know your glucose and your insulin

and high, there is an improvement in the brain potentially as well, too. Yeah. So this also relates to another question that I often get. People say, well, I'm healthy. I already have the perfect body composition, and why should I pay attention to when I eat? And my answer is, well, we know there are few things. One is, even though you are healthy, one thing is it can actually keep your brain health much better.

And in fact, when we did our first study. on humans. And this was eight years ago. 2015, the paper came out. And there are only eight participants in their study. And this was very early days. We asked, is it feasible for people who have

been eating for a long time throughout their life last 15, 20, 30, 40 years? Can they change that habit? Because this is a big issue in behavior change. Sure. Because we are so married to our old habit. Imagine, even for coffee,

means a lot of people, they cannot give up coffee. It's not that they're born with a coffee in their sippy cup. We picked it up along the way. But we got so used to coffee that we cannot leave it. So similarly, people who are used to snacking over a long period of time, the question is, can the change behavior? And in that study, there are only eight people. And again, this was funded by an innovation grant from the Salk Institute by a philanthropist.

And when these eight people, they stuck to a 10-hour time restuating. So that means they were allowed to eat for 10 hours. They self-selected that 10-hour's window so that that fits with their lifestyle. And they have to do it only for 18 weeks. That was the advice that, okay, so we'll do the study for 18 weeks. At the end of 18 weeks, we'll collect some data, and then you are free to go. And so they were free to go after 18. They were not even obese people.

They were mostly overweight BMI somewhere between 25 and 30, and the average BMI was 27, and they lost a modest amount of weight, 3.5% body weight. We didn't actually measure at that time body composition, whether that is fat loss or muscle loss because it was a pilot feasibility study. But what was interesting was after a year, we were curious because in many behaviors, behavior intervention, people actually can't change their behavior forever. It's not sustained. It's not sustained.

And in fact, people who do weight loss trial, they try to reduce calories, change a different diet plan or get on a diet, they actually gain back a lot of body weight that they lost. Many of the benefits actually disappear. So that's why we are curious. We ask them to come back after one year, and then we realize that, to our surprise, they actually kept that weight loss. Even though it was a small weight loss,

we thought that they would gain back that weight. They kept that weight loss. And we are curious. So we had a very standard questionnaire about their daily habit and other stuff. And what was surprised to see was they said, all of them, they said it improved their sleep. They were less hungry at bedtime,

and they were more energetic in the morning. And they said the reason why they continued with the habit was not because of weight. because how they felt, how they were feeling that they were working at a higher performance level throughout the day. And that's the first time. This is where human studies are so important because when we are studying fruit flies and mice, we cannot ask the mice and fruit flies, how are you feeling this morning?

Right. And the mouse is not giving me high five. Yeah, and with the fruit flies and the mice, they also don't have free will to choose how much food they want like human beings do. Yeah. So this was the power of doing a human study and then following up with the individuals. Yeah. And another thing, the difference between human and mice is actually we did an experiment where the mice had to eat nine hours Monday through Friday.

And then we get them a cheat day, weekends were cheat days. So they were allowed to eat whenever they wanted because the food was given 24-7 on the food hopper. And they did not, they actually don't learn the habit. So that means they continue to eat 24-7 in those two days. They over it. The good thing is they still had a lot of health benefits, almost 80% of health benefits. From practicing the time-restricted eating. Just for five days.

For five days. And that was actually eye-opening for me because I thought that all these benefits will go away if they cheat for two days. And because, you know, when these mice are eating randomly, then they're also disrupting a circadian rhythm and other stuff. And that gave me hope that even humans, hopefully, if they eat, if they try to do time ratio eating, even for five to six days, that can have health benefits. So that key experiment in mice give us hope. But in humans, it's very different.

When we talk to people who have been trying, and most of our studies are 10 hours time I'll get back to Y10, not eight, not nine, non-six, six, et cetera. They say that they get food hangover if they eat late. And this is something that our mice never told me. And then, again, a lot of people, they actually, when I think of hangover, it's mostly alcohol. Right. But then I came to understand this from people's point of view because they said, well, food hangover is when you eat late and when you wake up in the morning you feel like the food

is still there it's not digested and you feel groggy and you don't have appetite to eat and your whole morning is spoiled and it's almost like a hangover from alcohol but it's from food and we realize there are a lot of people who actually try this if they eat late into the night their body revolves and they remind them hey these are the immemales immediate bad things that you'll face. So that's something that we realize that in the human studies, that time restating has an impact on sleep. Again, we don't know why.

Because sleep researchers essentially study sleep. Nutrition researchers don't ask questions about sleep. And this is a challenge for people like me, because when we want to do a experiment and most listeners, when we think about health, we are not thinking about only how to improve sleep or how to improve exercise or how to improve food. In a day, we always think about all three aspects. And it's very challenging to measure, objectively measure all this stuff, even in mice. Forget about humans. We are not talking about humans.

Totally. Yeah. So this is where combining mice. mouse research and human research actually helps us to go back. Now we know that, okay, so it improves sleep. Then we're going back and asking, okay, so what happens? Now, people who do time restating or mice that do time rest of eating, do them, does their brain remember that sleep date when they get older?

And that's a very fundamental question that we're trying to figure out in basic research. And then we go back and ask the same question. months. Why do you think it is that as you get older, your mind is forgetting or cannot easily remember the sleep debt? Is it just the degradation of the brain? In your case, you were saying, like, you know, getting rid of caffeine temporarily for a period of time, helped you return to baseline. But you were even saying an older mice. Yeah. That they're not as good as the younger mice in remembering the accumulation of sleep debt. So is there a reason that you think if you had to guess? Do you have a hypothesis, an idea about why that's happening?

This is where actually we don't know. My humble answer is we don't know, and this is where there is scope for research, because even when we do research on mice or fruit flies, we rarely study older mice or older fruit fly. The reason is very simple. Let's do the simple math, even. You know, a mouse is pregnant for 19 days and then gives birth, and then after seven weeks, the mouse is adult. And you can study this mice, these, you know, 10 weeks old mice are almost like a 19-year-old human.

Right. And the simple economics is a 10-week-old mouse will cost me maybe $50 to purchase from a reputed source that gave all the full, all the health records and I get a mouse that is perfectly healthy with no disease, no infection, nothing, and then I can do some experiment. Now imagine that 24-month-old mouse is equivalent to 50-to-60-year-old humans. And that 24-month-old mouse will cost me at least $7 to $800 after factoring in how many mice I can purchase from a reputed source and how many of them will be healthy without any confounding disease that I can use in study. If you're going to study an older mouse, that's healthy.

It's just going to cost way more. More than 12 times. And that's even if they can make sure that it was, it actually stayed healthy. Yeah. So that's the challenge. And so over the last 50 years of biomedical research, everything that we know comes from studying disease or disease models in young mice. We haven't actually invested that much to study what is aging. Very simple idea.

Why we age or when we age, if we think about a specific some milestone, because we have to first think about what is the milestone that defines we have aged. For men, it's a little bit difficult to define. For women, it's very simple to define. Menopause is a very well-defined milestone. And menopause will happen somewhere between the age of 45 and people. And the question is why that happens? We still have no answer.

Similarly for most people, our insulin sensitivity will begin to decline, say, after the age of 50. And the question is why is that? What happens to our insulin producing cell? Is it the sensing mechanism? Is it the processing part? Or is it the production part? Or simply these cells, we use the word adjusted, but what is the disease?

definition of exhaustion. Can we figure out what is the molecular mark there that says these cells are exhausted? So very simple thing that we take for granted we think that oh, scientists must have figured this out. No. We haven't figured out who we are flying in the dark. We are just trying different things. So I guess the next 50 to 100 years of biomedical research hopefully will be to figure out why we age because age itself is the biggest risk factor for all kinds of diseases. When we get older, we are more prone to infectious disease. When we get older, we are more prone to metabolic disease. Just 65 years of age, if we look at the stats, in this country, 90% of people above the age of 65 have at least one metabolic disorders. Either they

have too much fat or too little muscle, or they are diabetic, or they have high blood pressure, high cholesterol, all these factors. And so age itself is the biggest risk factor, and we don't know why that happens. Even when it comes back to circadian rhythm, because we're talking about circadian rhythm, as I mentioned, our sleep quality degrades so that it becomes very difficult to sleep as we get older.

And when you don't sleep, we are more prone to eating later night and getting exposed to light, that itself puts us into a very much, is your cycle. So I guess the simple way to think about our journey through life is when you are young, you're almost like on a self-driving mode in Tesla because your circadian rhythm is robust. Just think about kids. You cannot keep kids sleep deprived from and keep them sleep deprived for five hours. Because, you know, when a five-year-old gets only five hours of sleep,

then there are consequences for the entire family next day. Absolutely. They will let you know. Yeah. So that's, I call it that's in the self-driving mode. And then in the middle is like from 20s to 50s, we're kind of going on cruise control. Means we can, a body can still manage to some extent if we take a little bit of care. But after 50, we're almost like in a manual drive mode.

We have to pay attention to all these things because our body is not keeping track. of when we should be sleeping, how long we should be sleeping, when we should feel hungry and eat, when we should stop eating. And this very fundamental question, why our circadian rhythm breaks down and cannot guide our body throughout 24 hours as we get older, that's also a big fundamental question

that we don't understand. You know, we recently wrote a newsletter on the topic for my newsletter about the topic of, sleep. And we were trying to help people understand that when you do not, when you chronically do not sleep well, here's all the things that you're at higher risk for. Right. We were just sharing the statistics. And inside of the newsletter, we were very careful to say like, look, this is not we are making you worry and to scare you, but we're just saying that this is a reason why to prioritize sleep. Yeah. And we had a lot of people write back and say, just reading this makes me feel

more stressed out, right? Yeah. And we wrote back to individuals and said, look, that's not our goal. We don't want to stress you out. But we just want to say, if you end up worrying too much about the perfect diet or this and these other stuff or you sacrifice other areas at the cost of your sleep, we're just trying to share the truth with you so that you're aware of what's going on. Now, what I've generally found, especially as you mentioned for older people as we age, 40 and above, you know, I just turned 40 last year, it's, it can be a little bit tricky to figure out the puzzle pieces. as to why we're not sleeping. It requires behavior change.

It requires, you know, shifting habits. You've mentioned a few here, having a consistent bedtime. Yeah. Keeping that three-hour window before sleep, a little bit longer. Great, if you have. Making sure you have those seven hours that are there. When you also wake up, I've also heard you say, like, resisting the urge to go for your phone, it'd be better to just lay there.

Yeah. Right? And then you could do either a meditation. You could do some form of cognitive behavioral therapy. I mean, there's other tools that are there. Maybe you have some other suggestions, but not immediately jump to the phone because people are awake and they're like, well, I can't go back to sleep. So let me do the phone.

But then the phone is shift work. Yeah. Right. Yeah. And so it creates a cycle and your brain kind of gets used to it. But I find that it takes a little bit of time for people to figure out what are the things that they can do and they have to practice it for a period of time. Yeah.

And then on top of that, if you are in a relationship, you're sleeping in the bed with somebody else. And if their sleep is disrupted, then that can impact you too. Yeah. Right. You know, not to mention we haven't even brought up temperature plays a role. I, if I get hot at night, I immediately wake up. Yeah. That for me is like, you know, a big thing, which is why I invest so much into like making sure I have one of those cooling pads. Yeah. Right. That's, it's been a huge win for me. So I guess I'm saying that, you know, when we have, this was some of the things that were, that were there, uh, to, to pay attention to the habits.

There was another newsletter, Tessa, maybe you could bring it up where we were talking about, it was a follow-up where we were talking about six crazy facts about sleep. So inside of here, we were saying, you know, number one, among people with Alzheimer's, 60 to 70 percent have at least one clinical sleep disorder. Poor sleep, number two, poor sleep and circadian rhythm disrupts disruptions increased cancer risk. Three, people who sleep just five hours per night are four point time, four point five times more likely to catch a cold. And it goes on and on, and we have all the references below.

So again, this is what people saw in there saying, this is stressing me out and making me even worry more so about sleep, right? So I'm sure you've heard that before. Within the context of it, taking a little bit of time to dial in all the puzzle pieces, is the answer that if you do wake up or your sleep is disrupted, is the answer to just stay in bed and do your best not to reach for the phone? Is that the answer that you share with people? Well, you brought up a bigger question.

I mean, see, you brought up a huge challenge. One is, you know, if you want to create a culture of health, then of course you're going to tell that if you don't do this, what is going to happen? What are the consequences? What are the consequences? So if you do this, what are the good things that is happening? Because that drives us every day when you're thinking about our decisions.

Our decisions are driven by, mostly by what are the bad things that are going to happen? Sure. like the reason why I did not smoke was I knew if I smoked. The negativity bias actually drives a lot of. So that information has to go out so that people know. So just simple facts that how we have reduced so much of infectious disease is if you don't wash your hand. Here's all the consequences. All these consequences.

And then the second thing is you offer information and then we have to offer opportunity to sleep in this case. So how they can create a opportunity to sleep. So this is where people can get all types of tips, including how to prepare to go to bed by not having bright light or food for two to three hours before going to bed. Then once you get into the bed, you brought up the temperature issue, and that's huge because our body actually cools down during night so that we can sleep.

And when our core body temperature goes up, then we wake up. And sometimes, as you mentioned, the room temperature may be high or sometimes the bed itself can reflect back a lot of heat and we wake up. Then the question is, okay, so if you wake up, then what can you do? Yeah, if you wake up, what can you do? Which happens to me every so often too, right? I feel like I wake up every morning and I feel well rested. But every so often, I wake up at like two. I've shared this before in the podcast. I'm still trying to dial it in. and I'm up for a little bit. So in that instance, you wake up,

what's the best thing you can do so that you don't end up becoming that statistic of you're staying up for two hours and how you're a shift work? Well, the thing is, first thing is, if you're just waking up, to go to the bathroom and coming back,

or if you're waking up, and then in California, it's very dry, some people wake up, they're breathing through the mouth, they wake up, take a sip of water, and then they're going back to sleep. So the bottom line is, if you're waking up and staying awake for less than 15 minutes, then you should not worry.

Then you're fine. Then you're fine. Just don't worry too much about that. You're in the good group of people who can. Only when you wake up and cannot go back to sleep for an hour, then it can be a little bit of worry, but at the same time, there is some context. Like, for example, people who take a nap during daytime, they're more likely to wake up because their sleep debt is not there.

They have already. They already got a little sleep in. Little sleep and then they're sleeping. And then they're more likely to have less deeper sleep. But then if you wake up, then it's pay attention to what is going on. Why you walk up, as you mentioned sometimes, it's the warm bed. And when I travel, there are many hotels where they actually don't have the perfect bed. So I always go for two queen beds.

If one bed is warm, I wake up. I just go to the other bed. That's a good hack. Or you just roll over to the other side and sleep. A cooler bed. To cooler side of the bed. Yeah, cool, side. And as you mentioned, don't open to see your text or emails or anything.

That's the worst time to kind of do sensory stimulation. Because whatever you see, whether it's a good news or bad news, either thing will keep you awake. Right. They can wait. The world is not. going to crass because you did not check your email or something. So I actually make it a point that I don't touch my phone until after I'm out of bed. Yeah. Do you put your phone on a lot of people put their phone outside the room or on the other side of the room? Is that somebody? No, I just have it

on do not disturb kind of more so that only if somebody calls me, it vibrates. And I know that the only person who would call me during that time maybe in case is my sister or my mother who lips in India and I know that. If that phone call comes, then something serious has happened. Sure, sure. That never came. Yeah. But other than that, there is no, so then the question is if you wake up, I must say

that there are many times, I also wake up and I cannot easily go back to sleep. So I have come up with my own hack. Yeah, what is it? What is your hack? Well, sometimes it's just, you know, a lot of the time we cannot go back to sleep because our mind is wondering and kind of, we're thinking about different things. stuff. So you might have a deadline. Something stressful happened that day. Yeah. So you feel like that's, irregular for you. Yeah. So it happens. It's part of life. Yeah. But in those cases, it's just,

you have to come up with your own coping mechanism. And my mechanism is to pay kind of, you can say, it's a silent meditation kind of stuff. I pay attention to my breathing and then I kind of count backward from 500. Every breath I take, I just count one. So, 500 and 499. It's very slow. But then what I have experienced is I have barely, I have really gone down from 500 to 300. You already fall asleep.

Yeah. And, you know, since one breath, one count, it's around 12 to 15 counts per minute. So by a few minutes, I'm, I lose count first. And then I'm, okay, so then I'm pulling asleep. So that's one. And then in most cases, what I've found is, There are cases there are some time when I was I was allergic or maybe I was not coping with

certain type of food. Okay. And I would wake up and then I would realize that yes, my digestive system may not be okay or my core body temperature is playing because my digestion is not right. So in that way I have gone back to changing food and that actually helps. I think another thing that's great too is that for a lot of people, you know, I think get as you mentioned, like getting up at night to use the bathroom and then quickly going to sleep, great, not a problem at all. What I find sometimes, and I've noticed this as I, I've noticed this in the last year for me, if I get up because I had a lot of water later on in the day, it's harder for me to fall asleep. If I don't have a lot of water, you know, before bed or even in the last few hours before bed.

and I don't get up in the middle of night to use the bathroom, I end up staying asleep the whole way through. So sometimes we have these different trigger points. And we just have to find out what that is so that we can adjust accordingly. Yeah. So sleep is a perfect example where the personalized pre-season health comes into play. Whatever works for you may not work for me.

And then whatever. So this is where people, this is a place where a lot of information about what helps, what doesn't help. different people will actually help individuals to figure out their own way to sleep. I know we have the app called MyCCDian Clock. Yeah, talk a little bit about that. And hundreds of thousands of people have downloaded the app. This is a research app.

We don't sell any information. We don't sell any products. And we follow HIPAA compliance. So that means that all the data is de-identified. Yeah, anybody can download it. It's at MySercadianhealth.com. My circadian clock. My circadian clock.

Let's bring that up, Tesla. My circadian clock, just so folks on YouTube can see it. Yeah. So you were saying. So, and then people who are sharing voluntarily sharing data, because this is, again, another thing. I'll go back to a little bit of how clinical research and how it actually impacts health. If you go back to, say, intermittent fasting or time receiving, all the study is ever done.

and you combine how many people were in those studies, there'll be less than 2,000 people. Wow. Okay, out of those maybe three or four studies, which are an randomized control trial, well done, they have less than 500 people. So just imagine all the scientists and all the podcasters and thought leaders like you,

we are talking about results from 500 people. And most of them would you say as men, young men? Yeah, in many cases, it means it's mixed. Sometimes it's only female also. There are many studies. But the point is there are very small number of people who participate in clinical trials because it involves a lot of trips to the clinical center. And also it involves giving blood, following a lot of instruction.

So we thought, how can we capture more data from people? There are a lot of people who are willing to. to share some of their lifestyle data, what they ate, how much they ate, when they ate, or what they're facing in sleep, how much they're sleeping. So we met this app where people can download and then for the first two weeks, we asked them to just log your regular habit, food, sleep, if you want exercise or pair your device or your phone with the app so that we can get your step counts. So now from there, we have to be a little bit. So now from there, we have to be able to have a few hundred thousand people who have shared their data.

And then what we think about, okay, so we ask every day, how was your sleep? And they have to rate whether it's good or bad. And then if they say bad, then we ask them, what are the three? There are three causes of sleep disruption or three major complaints. One is difficulty falling asleep. So you go to bed, but you cannot fall asleep within 30 minutes. Most people fall asleep within 30 minutes. Some people cannot.

And that's worrisome. When you cannot fall asleep within 30 minutes of going to bed, then you're going to start thinking about some strategy. The second is fragmented sleep. You wake up too many times or maybe one time, but you are staying awake for a long time. You cannot fall asleep. You cannot fall back asleep again.

Third one is insufficient sleep. Maybe you are sleeping only five hours or six hours. It was perfectly fine. You went to bed. You went through all five hours of sleep, but in the morning you have to wake up for commute or work or something else. So you're putting the alarm clock and you're waking up. So these are the three major complaints about sleep.

And then we ask anything else, what cost? What we find is surprising. That's never discussed. One is a lot of people actually have a pet who sleeps with them. Yeah. And the pet can wake them up. Yeah. Dogs wake up so many times or roll around at night, have dreams.

Yeah. Have nightmares. Or the cats, they actually, cats are crepuscular. So that means they are more active in the evening and also more active in the morning. So before you wake up, cats want to have their food. So we're also seeing that a lot of people have pets in the room and they feel like that their babies and I respect me. It means, yes, pets actually give us a lot of emotional comfort and all the stuff.

They feel like a family member. They are, family members and actually many pet, they, they, describe themselves as pet parents. So that's fine. But you got to also keep in mind that for your health, better health, and also your pet's better health, you should also just like you have to train your baby to sleep through the night and put your baby in a cream.

Most people do similarly. Have your love for your pet outside. You're sleeping hours. That also helps. And you also mentioned, like, if you're sharing a bed with somebody and then the other person having sleep issue or snoring that can also affect your sleep and pay attention to that. I mean, I also have some little bit of interest in architecture.

So I go to many old houses of people and there are quite a few very nice well-preserved houses in LA, Los Angeles area from town of the 20th century. And if you go to those houses, what was interesting, what struck me really was how in those houses the couple slept in separate small beds. They slept in different rooms, either in separate rooms or in separate beds in the same room. And going back, actually, I realized that even my grandparents, they had two separate rooms, two separate beds in their room, to sleep. So this is really interesting to sleep in the same bed.

Of course, it's very difficult nowadays with these. rental price so high and a lot of people cannot even afford to have a one-bedroom apartment. It's a challenge, but this is something if you can do, think about it and to see whether you can sleep in a separate bed. It's not taking away a lot of your love for your partner, but actually it's a lot of respect for the other person's sleep need. And when people sleep well, means one thing that we have to also acknowledge is a lot of family stress comes from someone not sleeping enough and not coping with this stress that comes with raising kids, having a job, and coping with your partner. Yeah. No, it's a super important topic. It's difficult for a lot of people to explore that, but then once things get bad enough, and for a lot of people that it is bad enough where they need to start thinking about other strategies. Yeah.

And I would say that one low-cost thing, if a couple is not ready, if you're sleeping in the same bed with somebody else, this wouldn't work for pets. But if you have a partner, I even recommend that if you're not ready to sleep in separate beds. And right now, my wife and I, we sleep in the same bed, right? We're not in different rooms. Yeah, yeah, yeah. You know, we have one big, big bed. California King, we have separate duvet covers. Yeah.

Mine is very light. Yeah. I need it breathable. I get very hot. and hers is very thick. She gets cold at night. And that's something that's there. And if she tosses in turns, she just pulls her blanket.

Yeah. That's there for her. And then if I toss and turn, I just kind of pull my blanket a little bit. And that's definitely helped both of our sleep scores. I track on whoop. She uses an aura ring. And so not having the same duvet. Yeah.

Has definitely helped with especially the temperature and the tossing and turning on each other's, you know, blanket and everything. So that's one little thing. that I've found, that's helpful. Yeah. Well, I love how much we've talked about sleep. I feel like that's been super helpful for folks. Let's just do a little bit of a recap on the sleep side, right, with the caffeine recommendations and everything else.

But even add in just what you know about movement, right? Does movement play and does exercise and our circadian biology, does that impact our sleep at all from anything that you're aware of? Yeah, exercise does. improved sleep, people who exercise regularly, they always report better sleep than those who don't. Or people who have never exercised and they start exercising, they also report that they are sleeping better. And a lot of the time we think that by exercising you are just tired and you can sleep. That explains why people who exercise can sleep. But what is the molecular

definition of being tired? So that's what we are thinking. So right now what we know from basic circadian rhythm biology is these are these type of experiments we can do in small animals in laboratory. So this is again another really nice experiment, well done by another researcher who is at UCLA Ketema Paul. what their group did was we have what we call cloth genes. So just like the genes give you eye color, hair color, skin color, etc. There are also genes that we all have that help us to tick this 24 hours clock. So that means if we have a mutation or if we don't have that gene, actually, I don't know anyone in living human who doesn't have a complete set of clock. genes. They might have a slight tweak so that they may be designed to go to bed early or wake up a little early, but there is no human that we know of that has completely lost all the clock genes. But to understand the impact of this clock in laboratory, we can make mice that don't have a clock gene. And these mice sleep like babies. That means they sleep for one or two hours, wake up, eat little bit, and then go back to sleep. So they don't have any.

circadian rhythm of sleep or wakefulness. So now this group did a very interesting experiment. What they did was, they made a mouse that did not have any clogging. So the mice were waking and sleeping at random time. But then they made a trick in that way only in the muscle. They had a clock, not in the brain, not anywhere else, only muscle clock. And toward their surprise, what they found was these mice now could go. to sleep and wake up like a regular mouse.

There is no difference between a regular mouse that has circadian clock everywhere in the brain, muscle, gut, everywhere, versus a mouse that has clock only in the muscle. It's as if the muscle clock is in control of sleep wake cycle. And again, this is a crazy experiment that they did, and we still don't understand what is the signal from muscle. that's actually telling our brain to sleep. So we started a new set of experiment. It's a new line of research essentially in my lab.

We are looking at what are the signals from muscle, tendons, ligaments, all the connective tissue in response to exercise that affect our gut microbiome, our digestion, our metabolic health, brain health, even depression, anxiety. etc. What you're finding is when mice exercise, we can take specific muscle type, what are finding there are at least 400 gene products like proteins, hormone-like molecules that are secreted from muscle. And that may explain, and maybe in those four to 500 things that we have now found, one or two of them may be involved in the sleep regulation. And why this is a so exciting is in the past we had no idea that muscle plays a role in sleep and second

just like any cell muscle cells also have 25,000 genes out of 25,000 genes which ones are good of which ones may be the candidate we didn't know but the simple experiment and doing very molecular studies now we have narrowed down from 25,000 to two to 300 and out of those now we can go back and figure out which one or two may be important and then go back and see whether those ones respond to exercise and whether they mediate the effect of exercise on sleep. Then now to close the loop, we can go back to older mice and ask if old mice exercise little bit can they also improve their sleep and the brain's capacity to calculate how

much sleep date they have and can they go sleep? if we find those specific hormone-like molecules, then it's also possible that in future we'll have a new type of medication or drug that is more specific for the sleep effect than ambient or anything else that we have. So this is, again, an exciting field. And going back to your original question, yes, muscles, activities during afternoon, again, we'll go back to why afternoon exercise, but that seems to improve sleep. The other thing that also improves sleep, again, this is a surprising finding.

It's a collaboration, again, with Thwarasio Delaclesia from Udub. What we found is people who have exposure to outdoor light, daytime bright light being outdoor. Somehow, we don't understand why that nighttime melatonin goes up and they can sleep better. And this is something that he did with free-living people outside. But I went back to literature and I figured out that, no, actually, people knew this for almost. Some scientists had done this experiment almost 20 years ago where they had people inside the lab. This is where the lab research is also important because one might say, well, we don't know outside what happened. These people are walking around.

Maybe they had some food, something else that boosted up their nighttime melatonin. So this research which was done in Japan where they brought healthy volunteers and then the same volunteers got either dim light during daytime or bright light. That is 5,000 locks of light. We'll get to that. And those volunteers who got 5,000 locks of light during daytime, they had higher melatonin at night time. We still don't understand why, but at least we know that daytime bright light. improves your nighttime melatonin and indirectly might improve your sleep. So just like we were talking about the importance of having a caffeine cut off. Yeah.

And every so often maybe once a year, doing a little baseline of returning to no caffeine, you know, you know it's tough to kind of improve sleep, getting that morning sunlight, that daytime sunlight. Does it have to be morning or can it be any time during the day? So this one was any time of the day. Anytime during the day. Anytime during the day. So that bright light that comes from outside, not inside, because as bright light.

is bright as it seems in here, even in our studio, it's nothing in comparison if you measure it to how bright it is outside. So getting outdoor light during the day directly on the skin. Is that important? No, the skin is not that important for circadian rhythm. It's actually the light that goes through the eye that impacts our brain health and circadian health. And you don't have to look at the sun. That's very important because going back to when I said 5,000 locks. or 10,000 locks. One locks is very dim light. One locks is roughly in a very dark room at night time.

If you have one candle light, and you are sitting roughly two feet away from the candle, the amount of light at your eye level or your face level, that's one locks of light roughly. And right now in this studio, I would estimate there is somewhere between 500 to 800 locks. a flight okay now if you open that large window and if we sit right next to the window that will be also 1,000 locks a flight now the regular people who are going to different

stores and buying almost all of us we go to stores and buy grocery by drugs by medicines if you walk into a regular grocery store these days in the evening that's somewhere between 1,000 to 1,500 locks a flight and if you walk to inside a 7-Eleven corner store or Walmart then that's also 1500,500, 1,500 locks of light and then on a cloudy day in LA or cloudy day in London outside there is 5,000 locks of light right just imagine even when you walk into that grocery store you might be feeling this is so bright but in a cloudy day we have four times more light outdoor.

Sure. So that's why getting outdoor, even on a cloudy day, or if you are even sitting on your pores or maybe outdoor under a tree, that itself is enough light. That's enough light to stimulate this effect.

To stimulate this effect. Of evening melatonin, which makes it easier for you to fall asleep. Yeah. But another big effect of light is light is the best antidepressant because light also suppresses many brain functions that are linked to depression. And in fact, this is well known for more than a couple of hundred years

because all the people who live in the Nordic countries. So that's Sweden, Switzerland and all this, Norway, they know that in wintertime when it's so dark outside, when it's almost 24-7 dark for a few days, they barely get two to three hours of daylight, that not having enough light, because it's also cold in winter. Not many people are going outdoor.

That causes depression. So that's why there is the storm of winter blue. That means in winter time, when people don't get enough light, this is what happens. And we think that we are getting enough light. But actually, unfortunately, there are not too many smart watches that can measure light and tell you how much light you're exposed to. I wish there were even eyeglasses with light sensors. Right. That would let you know, like, hey.

Yeah. Just like my watch was. tell me, hey, you've been sitting for too long, it's time to get up. Yeah. A watch that would say, hey, we're not seeing enough light exposure. It's time to get a little bit more light. Yeah. So we do put this watches that are FDF approved for measuring light.

And of course, these are on wrist watches also on the wrist. So that means we're not measuring how much light is at the eye level. Sure. But what we're finding is even in San Diego area, which is considered where my lab is. And people always think sunny San Diego, sunny California, people are all happy and all that stuff and people are outdoor. But what we find is a lot of people, I would say, more than 75% of our participants in our studies who wear these watches,

they get less than one hour of bright light outdoor. And me included in some cases. And what should we be shooting for? if less than, what percentage gets less than an hour? 75% get less than one hour. And what should we be shooting for? One hour at least. One hour at least.

Yeah. So 75% are not even getting an hour. Getting an hour. Yeah. Because just imagine, we are mostly indoor. Yeah. Most of us actually, you know, in California, we don't even walk to the next bus stop.

We walk from our kitchen to the garage and then get in the car. Get in the car. And when you are driving, we all. Also, a lot of us, we have sunglasses. Sure. And sunglasses can reduce light by sometimes by 80 to 100 folds, depending on which kind of sunglasses. And, you know, I'm a light fanatic, so I had light sensors with me all the time.

So I realize that inside my car, I get maximum 5,000 to 10,000 locks applied because you're not getting direct sunlight. Most of the time the sun is above. And on top of that, if I'm wearing sunglasses, then the light at my eye level is less than 500 locks. It's almost like staying indoor in a closed office room. And then I reach my work and then I'm walking from there to the building. That may be the time when you have some exposure. Some exposure because the outdoor light, if it is sunny in San Diego, then it's 100,000 locks of light.

even if you take 95% of that, I still get 5,000 bucks. So I realized that, yes, that was the, that was what I was getting. And there was a time when I actually, I was on a safari in, in, in, in, in, in, outside Nairobi. And that's the time when my watch clocked eight plus hours of bright light throughout the day. Yeah. Because I was outdoor in a, you know, in a, um, uh, safari vehicle. with all the open doors and windows, that's the one time.

And then when I travel, like, for example, when I'm in India, visiting my folks or I'm outdoor, that's the time when I get two to three hours of bright light. But back in San Diego, that was what was happening. And then I said, okay, so I'm not wearing sunglasses anymore. So I stopped wearing sunglasses only except when I had to go to the beach for, means when my daughter was young and I had to go to the beach for a couple of hours or something, then, of course, you have to wear sunglasses.

To protect your eyes, right. Or if I'm driving a long distance and there is a chance that there will be horizontal sunlight like at morning or evening. But other than that, for Delhi commute, I'm sorry, this is bad for sunglasses industry, but still, you should have a pair of sunglasses, I'm not saying. Right, right. But, and usually outdoor light is a direct reflection of walking, right? If people are going to get light.

Yeah. And the beautiful part about that is you can stack behaviors because people only have so many hours in a day. Yeah. So we know that movement can help build up sleep pressure. Yeah. Right. Yeah. And also improve our metabolic health.

Walking can improve our metabolic health. And it's also probably going to be the time that most of us, even on a cloudy day, it's been very cloudy in San Diego and in LA the last month, right? down there where you guys are too. And even on a cloudy day, I have to remind myself like, no, there's still so much light that's outside and getting that regular, you know, even just, you know, I understand it's idealistic to expect us all to be able to walk an hour a day. But if you're privileged enough that your schedule can allow it, spending time, and then

I'll try to stack that. I might call a friend, you know, on the phone and I'm talking to them and I'm catching up with a friend or a family member. It's tough, but I sleep so much better. when I get that walking and I get that light exposure during the day. And then it's like it's almost worth it to put in some of that. I'm not saying it's easy, but it definitely feels worth it. It is worth it.

And this is also another time when people are talking out flexible, working hours or hybrid and they're staying all day in their home. And one thing that should be doing at least is in the morning. Another thing is in the morning, you talked about morning light. And in fact, the morning light is the biggest synchronizer. of our internal clock and outside time because a body has to learn one is the morning time. Of course, it is anticipating or snowing, but it needs that reinforcement. Yeah.

So, you know, sometimes particularly kids, college kids during COVID time, they were always indoor. They were doing everything over Zoom. And a lot of people who used to go to office, they were working on Zoom. and they always complained about this solitude, feeling lonely and very poor brain health. So I always wondered how much time they were actually spending outdoor because there was a time when we kind of build the habit that you have to be indoor because everything is bad outside.

Right, right. So dangerous outside. So dangerous outside. And infrastructure change so that we can. can be just working in our PJ all day. And that was really, that was, and we are now talking about the lingering effect of COVID and we are thinking about some virus or long COVID. Of course, that may be some part of it, but the point is we changed our habit to stay indoor. So even now, my daughter is in college and I always tell her that, okay, so after you wake up, just make an effort to go

outside and walk for 10 minutes. Yeah. It's not one hour of walking or 30 minutes. Just go. I mean, she's a resident advisor, RA. So I said, yeah, so in the morning, you take the round, like, you go around your building and come back and see. And she says, wow, I love this fresh air. I love this.

Fresh air. And it's almost like a switch because, you know, so once you go outside and even I, I have experienced, I also experienced this because I wake up and go outside just to check the plants or, you know, one weird thing that means these days everybody is reading everything on digital, but I still love the feeling of having a physical newspaper because there is no distraction. There is no advertisement on the side. There is nothing popping up. So I wake up, open my garage door, go outdoor to pick up my newspaper.

and that itself, just going out, getting that fresh air, seeing what is the temperature, sensing the temperature outside, and seeing that light, it's almost like a trigger point that just tells my body and brain that, and even though I'm tired or something, and that five or ten minutes outdoor, does magic. Makes a huge difference. Huge difference. So these are the small things that people can. You don't have to get a gym membership.

You don't have to buy extra food. So that's why I'm saying. Light is the best antidepressant. It's a mood switch. It's plentiful. You can still have in your PISA. You can go outside. Just open the sliding door and step outside or go to the balcony.

Stand there. Drink your coffee outside. Drink your hot tea or radio newspaper. Whatever you want to do. And do you also feel, so we talked about morning light, general daytime exposure. But is there also? something to support sleep, since we're on that theme, is there also something to seeing evening light that supports our sleep? Yeah. So light any time of the day is very important. Because

always just sinking your circadian clock. Yeah. Yeah. So that's one aspect. And second is the mood also improves because we also know that people who are more depressed or those who experience anxiety, they also have sleep problem. Either. they tend to sleep too much or they sleep less because of the anxiety and depression, they cannot fall asleep easily at night. So it has an indirect effect. And this is also important because in our lifetime, I'm not talking about at any given time. In our lifetime, almost 80 plus percent of us will experience some kind of depression or low mood. It may be, it's not that clinical depression, but, you know, any time there is a bereavement, whether

it's your pet, whether it's someone you love, or whether it's your friend, somebody is having an accident or somebody is struggling with cancer or some kind of berement will cause us to feel little depressed. And a lot of us will actually have clinical symptoms of depression. 15% to 20% will have in our lifetime some clinical symptoms of depression. And this is where being outdoor, having that daylight, and as you said, layering different habits. This is where, okay, so the first thing is to get outdoor. Second will be, can you combine it with exercise? Walking. And then the third one, can you walk with your friend or somebody else that also combines this societal, social support system, social network, and all of these things

can be layered. And these are free. These are some habits that people can. can build. I want to go back to movement because you hinted that there could be an optimal time that our body is ready for more strenuous exercise. You know, we've had a lot of people come on this podcast, talk about the importance, especially after the age of 40, like researcher Donald Lehman, who has shared, and you've hinted at it at the beginning of the episode, sarcopenia is a big problem and muscle loss. and how if you don't regularly have muscle stimulation

through strength training or something, you can see a decline. I think it was 8% every decade after the age of 40 you can have in muscle loss, which can cause a lot of other situations. So when it comes to more strenuous exercise that people are trying to work in to try to hit that 150 minutes a week,

you know, that's recommended. What does circadian biology help us understand about the best time to do that? Yeah, so just like every sense, has clock our muscle cells do have clocks and that means our muscle cells might have a peak time when they should perform but at the same time we have to also think of movement or exercise as a what we call the emergent property or a combination of many things working together so for exercise our lungs have to

work much better so that we have better oxygen inhalation and use of that oxygen to oxygen as the body. Heart should be also pumping blood well without getting stressed. And there are many other factors that have to kick in. Similarly, our joint or the muscle temperature has to be a little bit warm so that there is better flexibility. Many of us, we experience that joints are little stiff

in the morning, but they get much more flexible towards late afternoon. So these are many different things that actually change in a way that our body is more likely. So there are two things. One is our body is more ready for exercise. Joins are more flexible.

Our heart is pumping much better. Our lungs are functioning at a higher capacity. And finally, our muscle strength and coordination are also much better in the late afternoon. So if you combine all of these, then it makes sense that the late afternoon exercise is better than morning exercise of the same quality and quantity of exercise.

Then there is another reason of late afternoon exercise having benefits, that is its impact on blood pressure and blood sugar. And why this is important is in this country right now, in the U.S., almost 50% of adults are either pre-diabetic or type 2 diabetic. And in California, definitely more than 50% of adults are pre-dietic or type 2 diabetic. That means the blood sugar level remains high.

Fasting blood sugar level and also post-frontial blood sugar level may be high. That reflects in hemoglobin A1C being higher than 5.6, 5.7. And then we also know that, more than 50% of adults in this country also have either mild or more serious blood pressure, higher blood pressure. And what is interesting is there are a lot of papers dating back to 70s, 80s, 90s showing that we know that exercise benefits blood pressure and blood sugar. No doubt about it. But what is interesting is late afternoon, early evening exercise is much more potent in reducing.

and normalizing blood pressure than morning exercise. And research in the last five to seven years have also shown that the same high-intensity interval training, if done in the morning or afternoon, on the same individual, this is very important, this is a crossover trial, the same individuals who are type 2 diabetic and who are wearing continuous glucose monitor so that we can see glucose level 24-7

when they exercised in the morning, their blood glucose level, 24 hours blood glucose level either remained the same or actually worsened. They raised a little bit higher. And the same individuals when they exercised in the afternoon, the 24 hours blood glucose actually reduced significantly. This was done on a small number of individuals, and now this study that came out of Karolinska Institute in Sweden there. planning a bigger study, but now we are seeing it makes sense for few reasons.

One is, let's go back to what I mentioned at the very beginning, that how a pancreas is much more efficient in producing insulin for the first half of the day. And that means for the second half of the day, for the same amount of food, it's actually producing less amount of insulin. and that means there is all this food that we're eating late in the afternoon or early evening that needs a little bit of extra boost for that food to be, for that glucose to be absorbed in muscle because our muscles are the biggest organ in the body and they also consume a lot of energy.

So what is interesting is late afternoon, early evening exercise or any time exercise actually helps our muscle to absorb a lot of glucose and use them with no or minimum help from insulin. So that means when our insulin levels are low in late afternoon, then muscle, sorry, physical activity can make good of that low insulin production or low insulin sensitivity. So that's why I would say almost everybody is going to think about even if you are going to gym in the morning, that's fine, but in late afternoon early evening, if you have free diabetic

or type 2 diabetic and I'm sure many of the listeners either they themselves or they know someone in their household who is fighting this free diabetes or type 2 diabetes they may start thinking about switching that exercise

either before dinner or after dinner and it doesn't have to be intense exercise and what we have seen, even people who are just taking a brisk walk for 10 to 15 minutes before that dinner, after that dinner, they also see some benefit. So start from there. Yeah. And generally would you say for people, just because exercise is so tough for people to be consistent when you look at like a national level, especially if we're talking about incorporating and strength training, would you say that the benefits of just getting any regular,

amount of that, you know, it's like they say like two to three times a week when it comes to strength training. If we're looking at that level, this is people who already have maybe the a little bit better than the average when it comes to steps. I think the average when it comes to steps is like 4,000, right? And I think less than 6,000 is considered sedentary lifestyle. Right? So if you are semi-active, which a lot of listeners are here, and they're really starting to pay attention to, hey, I'm trying to get that strength training component because I want to avoid losing muscle mass as I get older. Generally speaking, you know, because everything's a pros and con.

It's still going to benefit you from just getting in that training anytime. Yeah. You can in the day because the overall benefit to maintaining muscle mass. Now, that being said, pay attention to your performance. Yeah. I personally used to wake up just because the schedule, I'd go to the gym at like 7 o'clock. I'd just get it done. I'd feel like, oh, I'm great.

I'm good to go. As my workouts have gotten tougher, I'm working out with a group here in Los Angeles that does heavy strength training. As my workouts have gotten tougher, a few days, I just had to naturally end up scheduling my workouts later in the day, like take a break from all my meetings and everything or maybe after a podcast. And I'd go in at like one o'clock. My trainer would just say, like, I don't know, maybe you slept better last night.

You're just performing better. And I think for me, it's just the combination of all the things you mentioned. My body's warmer. I feel a bunch of different things, but I just perform better. I'm able to lift more weight. I'm able to do more reps if it's a little bit later in the day compared to in the morning. But that being said, that's just me. And we probably know based on circadian biology, that's probably going to be a lot of people,

but in general, for most folks who are listening, who have fought very hard to exercise regularly, you know, just get that exercise in and then you can tweak long term. Is that a fair assessment? Just get some exercise first. Just get some exercises. Some exercise and then you can tweak long term. Yeah, great. Yeah.

You know, you talked about performance. And actually the history of afternoon exercise or circadian rhythm dates back to 80s when some researchers actually had the curiosity to see what happens in the late afternoon when West Coast team flies to East Coast and plays Monday night. football. Interesting. So these guys, they may be, you know, they are playing

too many games in a season. So they are most, they don't have the luxury of flying to East Coast and waiting for seven days before their games. So they flew as supposed to Sunday and then Monday if they're playing, most of the time

the games are going till 9 or 10 at night. And 9 o'clock or 10 o'clock night in the East coast for the jet-lagged West Coast team is actually six or seven in the evening, which is at their peak performance time. Peak performance. So somebody went back to getting the travel record and game records of 25 years of NFL,

and they figured out that the chance of West Coast team winning against the East Coast home team. Okay, yep. Even so the East Coast team has the home court advantage. Home court advantage. if they flew on Sunday and played on Monday, West Coast team has a advantage, has a higher chance of winning. So all the sports battles outside.

Everybody's going to Vegas. If you can figure out when your team is traveling and when they're playing from which time zone to time zone, actually that particular paper compared that against Las Vegas odds score. And they found that if you know the travel date and when your team is performing, you can beat Vegas. I love it. That's great.

And this has been now repeated again and again in NBA and other games. And that has led to many elite athletes planning their travel, when they should travel, or when they should practice. So, for example, if you're like if you're competing in Olympics, it's actually a huge challenge because sometimes you're qualifying hits. the morning, whereas your final or semifinal is in the afternoon. Right. And this becomes very tricky when they should practice and when they should shift their secret.

Because, you know, for you and I, it doesn't matter. One day I can. You're not at the lead level. Yeah. I can be slow for maybe by five or ten seconds and it doesn't matter. But for those athletes, even fraction of a second matters. matter. So this is a clear example where actually the timing when you trend, when you travel, and when you're competing has a huge impact on whether you get the gold medal or you're out.

Yeah, I love it. You know, I want to reference a tweet that you shared. This was a few weeks, like a couple months ago, April 17th. I follow you on Twitter, so I see all your stuff. And when this came out, I was like, we have to write a newsletter about this. So I wrote a newsletter. I linked to your site. I credit you. Yeah. But for those of that are listening on audio, if you're on on YouTube, we'll show the tweet over here. And I'll just read it out here. So it says exercise is the best insurance against cancer. Again, off the topic of exercise that we're talking about here.

The premium is only 30 minutes of exercise a day. And you ended up tweeting and sharing this graphic from a study, I believe it was, talking about actually, maybe you can explain it a little bit. What is this graphic over here showing and what made you want to share this with your audience? Yeah, this graphic essentially says that if you exercise, then. your risk from many types of cancer, starting from breast cancer, colorectal cancer, endometrial cancer, gallbrador, kidney, multiple myeloma, ovarian, pancreatic, all this cancer risk goes down. Yeah.

And now let's think for a second. On this graph, there is no cancer of the muscle. Mm-hmm. You actually never see cancer of the muscle. Interesting. muscle constitutes the biggest part of her body. But yet, it's immune against cancer. And we don't understand why.

For some reason, muscle cells are very effective in defending themselves against cancer. Then the question is, why is that there are some intrinsic factor inside the cells or they actually secret some anti-cancer molecule? that protect themselves. And I guess we still don't understand why. My guess is it's the combination of both. Right. And so that's why there are a lot of people

who are actually interested in seeing when we exercise, what are the factors that are produced from the muscle? And if we take those factors and screen them against cancer cells, maybe we'll find a factor that is protecting against cancer. So that's why the idea is, Yes, when you exercise just in regular without exercise, even in sedentary people, we never

see muscle cancer. Yeah. Are you familiar with the seed and soil theory hypothesis of cancer? That idea that's sort of the environment combination of metabolic health, insulin, other things, the environment is shifted and creates the right stage. Jason Fung has written a book about this. Some other people have written about this. And so now you have a healthy cell, but now in an environment that's, you know, I'm dumbing down.

Yeah, yeah, yeah. You have an environment that's changed and a healthy cell that was healthy now becomes cancerous out of an evolutionary adaptation to survive in this new sort of setting. Yeah. And so just from the basics that I understand, it's very interesting because muscle, as you mentioned, it's the largest organ in the body. Yeah. And it's also the biggest user of glucose. Yeah. It's the biggest user of glucose.

It's the biggest producer of reactive oxygen species because mitochondria have to work. Totally. And this is a conundrum because and they also have multi-nucleators. So the cells have multiple nuclei, which again is a no-no for any other cell types. And at the same time, somehow the muscle cells, even, the sarcopenic old person is not getting muscle cancer. So even though, even people who have a gene mutation that causes cancer, that gene is mutated in all cells.

That should cause cancer in any type of cells. Right. But even in those cases, even if in mice, we, we pump up the activity of cancer-causing genes, we never see cancer of the muscle. And actually, there are two kinds of cancer of the muscle and also there is some few exceptions, but mostly in fat cells also we don't see cancer of the fat. Very few cases that are called lipoma. So I think these are the two organs and their existence to cancer gives us hope that we can understand a lot about what protects these cells. And when we exercise what muscle cells produce that reduce the risk for cancer. And, you know, there might be

multiple direct and indirect mechanism. One is, as we said, people who exercise, they also have much better sleep. And we know sleep disruption alone increases risk for cancers. That's an indirect mechanism. It has nothing to do with what is secreted from muscle that is acting on cancer cells. But at the same time, I think there has to be a lot of research on understanding why muscle cells are resistant to cancer. Yeah. And why physical activity increases resilience against cancer. And this is something that we have seen again and again. Even people who are going through chemotherapy, of course, it's really hard for people who are going through chemotherapy to make time, effort, and also the mindset to exercise.

cancer is terrible, you are kind of, you don't know what is the outcome. You don't know what will be life one month or one year. And then the chemo itself causes chemo fog. Many cancer medications have very serious adverse effect. But what is now becoming very clear is people who are going through chemotherapy or cancer treatment, if they can exercise, that accelerates their progress. So that means they can get better sooner. And it can also reduce the adverse side effects of many of the cancer drugs.

Because on day-to-day basis, what you really want is reduced chemo fog or reduce stress from just going through the treatment. And then the second thing that you want is your treatment should be more effective and it should give you much better outcome. And the third one is actually coming back to play. So return to play. So for example, right now in the U.S., there are nearly 16 million people who are cancer survivors.

They survived cancer, but we know that many cancer survivors also face other problems. Because during the cancer treatment itself, either due to the direct effect of the drug or something else, their disrupted lifestyle that they have to go through, unfortunately, that causes many changes to their cardiovascular system, their insulin regulation system, brain health, and they're at a higher risk for cardiovascular disease. They're also at a high risk for type 2 diabetes. So in those cases, again, cancer survivors benefit a lot by exercise and also time-rissue eating or intermittent fasting. Pretty much, I guess the moral story is everybody can benefit from regular exercise.

Yeah. And in here, in this study that you were sending out specifically about cancer, I do think it's important because, you know, you know, we're even telling people, hey, listen, any amount of exercise is going to be good. But what they were finding out is that like at least 30 minutes a day. Yeah. At least 30 minutes a day. At least 30 minutes a day. Right. So just great. We want to encourage walking. We want to encourage a lot of different things. But if we're looking for the cancer, fighting components of exercise, at least in this study, it's 30 minutes a day. Yeah. So there are two things here. I want to highlight. One is what is a personal risk for cancer and what is the likelihood that if we take 100 people and follow them throughout their

life, how many people are more likely to get diagnosed with cancer? And that number is pretty high. It's 42%. Yeah. So close to 42%. of us, we get at least one cancer diagnosis in our lifetime. And in that context, always what we want to do is reduce that risk. And if we get cancer, then we should accelerate that cure. And in that context, when we talk about 30 minutes of exercise, people may be thinking, well, do I have to exercise every single day? If I miss one day, then what happens? Is there an exercise debt? Can I pay that debt in the weekend? And And the answer, again, there was another meta-analysis.

Of course, it was not connecting with cancer risk. But what it essentially showed was the metabolic health benefits are still there if you're a weekend athlete. So that means if you're getting that 150 minutes of exercise over Saturday and Sunday, you're still getting most of the benefits of exercise. Oh, that's a great. That's a great reminder because, again, it's not about being perfect. Yeah. It's about just getting to that total 150.

minutes. Yeah. Right. Just getting that on a consistent basis. Yeah. Yeah. No, that's great. That's a really great reminder. You know, going back to this idea of the collaboration that you were talking about, where the researcher at GW found and led to the legislation in California, if you had to zoom out and you looked at sort of what's going on on a national level, even in a global level, as all the cities around the world have become industrialized and we all want the Western lifestyle, and the food and the diet and we're all up late night playing video games and phones and other things. In addition to sleep, because we talked about sleep, if you could change the work environment a little bit or the school environment or add to the knowledge that we have around circadian

biology, again, which your lab has been a big proponent of, what would be some other things on a national level that you would implement with your magic wand, that you would, that you you feel would have the biggest bang for the buck. Yeah, so let's start from very early childhood or even newborn babies. So one thing that has happened is, you know, there is a lot of light in our home and that light also, all the babies don't have,

we think that babies don't have circadian rhythm because they wake up and cry in every two to three hours they do actually have a circadian rhythm. Every cell in their body has circadian rhythm. They do something else. They actually help babies grow and be healthy. And the biggest impact of that circadian rhythm disruption, unfortunately, is among preterm babies. Babies who are born before they are mature enough to be born naturally or after full term.

And we know that preterm babies stay in the NICU, neonatal ICU, for several weeks. And that's a huge stress on the parents and everybody. And we also know that many free-term babies don't fully develop. Sometimes they live the rest of their lives with some issues, whether it's the vision issues, whether it's the brain maturity, metabolic health, etc. So what is interesting is, since we did not know the impact of circadian rhythm or how light and darkness affects our circadian rhythm, almost all NICUs all over the world were actually light at 24-7.

Yeah. And that constant light, although the babies are closing their eyes, and they don't have, they're not looking at the light 24-7. Still, they open their eyes and get that light. So there was a very simple study done in Mexico City. Again, these are some of the really outside the box experiment. Somebody read about our blue light sensing protein melanopsin that we discovered more than 20 years ago and how it regulates circadian rhythm.

And one key aspect of this light sensor that senses light and resets our clock is it's actually less sensitive to dim light. So that means people might have experienced when they have candlelight. dinner, they feel sleepy. Or if you have dim light at night, or for example, if you went camping trip and you have a little bit light, you fall asleep. There's still some light, but it's dim enough that you start to feel a little sleepy. Because that dim light is not bright enough to activate this melanofsine system,

this blue light sensing system that resets or disturbs our circadian clock. So this researcher, he came up with a very simple idea that, What if I don't have to actually switch off light in NICU, but dim the light? And still, he got a lot of resistance from doctors and nurses because there has to be bright light to see everything. We're going to make mistakes. Something bad is going to happen. And that's a genuine concern. So that's why he came up with a very simple idea that he would just partially cover the creams with a blanket.

So that at least on the head level, because, again, the idea is all. the light that disturbs our circadian clock actually goes through the eye, not through our skin. And in fact, many preterm babies need enough light signing on their skin to break down bilacids and many other things so that they can be healthy. So the compromise is he just put a kind of semi-harmament-like cover on top of the head so that at the eye level, the light is around 20 locks. So like having 20 candles in a room. Still, relatively bright, but it's not enough to disturb.

And during daytime, they had the regular light that was outdoor, that was in the NICU. We did the study on 50 or 60 preterm babies, and what he found was babies who went through this simulated

dim light and bright light, those babies were released from NICU because they grew much faster. They achieved a mile stones, 13 days before the control or standard of care. Wow. One day of NICU care in this country, I'm sure, it must be more than $15,000 a day. It's expensive.

It's very expensive. So we are talking about at least 10 days of NICU care that is saved by doing this simple light, dark cycle, right? Light and dim light, not even dark. And in this country now, in 2022, 2023, one in 10 life births is a preterm baby. So that means 385,000 babies are born preterm. In fact, anyone who is listening, they must know someone who had a preterm baby. And this is some practice that can be implemented.

In fact, I hear that in Mexico City now, this has become a standard of care. in many of the NICUs. So they implement this day and night or bright and dim light cycle. And just imagine, if we can delay, if we can reduce hospital stay in 385,000 preterm babies in this country in one year. So that's 3.8 million NICU days. That's a saving that will pay for all CKD. rhythm research ever done in this country and the idea long-term impact that it could be helping them develop better have less incidences complications as the older

the parents are much more happier because so this is one simple so many of these security and rhythm research implementation is either free of drugs free of pharmacotherapy or it needs very simple change in our standard of care yeah so now if you think about the next Since we are in the NICU, let's go to ICUs. Almost all ICUs have continuous light and also in ICU, since we don't, we did not know the importance of circadian rhythm or sleep. An average ICU patient in this country gets less than five hours of total sleep in 24 hours. It's horrific. For anybody who's had a family member in late stages or anybody in the ICU, it's almost like, it's like, it's like, it's like sleep torture. Yeah.

It's actually... Things are beeping. Yeah. Right? Not to mention the challenges with continuity of care, right? And just the normal medical system that's there. And as you mentioned, it's bright.

So you literally feel you cannot sleep if you're in the ICU. For anybody who's had a family, unfortunately, you know, my heart goes out to you. I've had a few. And it's almost like sleep torture amongst them. In fact, if you take everything that's done in ICU, constant light and constant frequent poking and taking blood samples.

If you do that to a healthy person in the normal setting, that will actually meet the definition of criminal torture. Yeah, that's crazy. And if you go to internal criminal court, those conduct, those things that all countries have signed, that if they capture a prisoner of war, they cannot torture them that way. What we do to our ICU patients.

Yeah, the only thing we're not doing is water, boarding death. Pretty much for doing everything else. Everything else. And still, we haven't implemented better care in ICU. And what is the impact? Because we know that one in three ICU admitted patients will develop delirium. They'll have no sense of time, no sense of where they are, no sense of context. And a lot of patients actually want to get out of ICU. They will say that, well, I'm ready to live all this pain, but please take me out of ICU. And so that's one challenge that we can improve the health of ICU patients by implementing some kind of circadian lifestyle.

And there is context to it. So, for example, in the early days of COVID when we had the first COVID drug, if you look carefully about the clinical outcome, it actually did not reduce. death. What it reduced was ICU stay by five days. So at that time, since ICU beds were so scarce and we wanted those ICU beds to be free so that we can treat more patients, even reducing five days, four to five days of ICU stay, literally if you think about the monetary value, that was almost $70,000 to $80,000 of savings, and then the drug was costing only $5,000. So it made sense. So in that context, now if we think about can we implement circadian lifestyle in

ICUs that can be done in this country, globally, everywhere, how many lives we can see. And now if we think about who are the patients who are likely to end up in ICU? These are mostly patients with sepsis, patients with very serious accidents and other conditions. In the US alone, there are 15 to 17 million people who get diagnosed with sepsis and have to be admitted to the ICU. And of course, the data is not very clear because the cause of death may be for many different reasons and there might be underlying conditions. But most people will agree that nearly 20% of people who get into who get sepsis, they're likely to die within two months. Yeah. And then those who survived, they also have a lot of comorbidities for the next one year or so. Now the question is, okay, so can we make a dent by implementing circadian lifestyle, lighting, darkness, or even practice in ICU?

And also once they're released from ICU, can we implement some kind of circadian sense, whether it's, you know, time-restrestating, but I'm not saying that they had to eat for eight hours, but even? if they eat for 12 hours among post-ICU patients. And if their sleep is taken care of, because when they come out of ICU, it takes them many weeks to actually get back to a regular sleep schedule. And so this is where this is another place where we can have bigger bang for the buck, for the attempt. So now you also asked what about, you know,

for school start time, for example, since 1950s, every year U.S. high school students were losing somewhere between 10 seconds to 30 seconds of sleep. So when they sleep 34 minutes more by extending or delaying school start time, we're essentially making our kids sleep as their grandparents were sleeping in 1950s. So this is another big win. Big win. The other thing you brought up is workplace. In any organization, less than 5% of people actually have a window. So a lot of people actually work indoor without having access to daylight.

And then the question is, can we change architectural design to bring light into the house? And again, this is another area where I go around and put light sensors. in different houses, buildings, dorms, etc. And what we find is a lot of the buildings are actually not designed to bring light. But the good thing is, glass is the best way to bring light indoor. Because if you have large windows,

then you can bring light. And glass manufacturing has gone through tremendous progress. So now glass has become a load-bearing factor in new buildings. So that's why you see a lot of big high-rise buildings. You still see big glass walls outside because, of course, they're not as strong as concrete. You cannot build a house with glass,

but still it has become so strong that you can afford to actually have bigger windows. And they're much better at temperature regulation. Temperature regulation. Which is why people didn't want glass in the first place is because it's both fragile, but also it leaks and it's harder to be. green certified, if you want the building green certified, but as you mentioned, there's been a lot of

development in that space. Yeah. So this is another area where we can actually go back to our ancestral living in the sense. Although we cannot go outdoor, can we bring daylight into a workplace? And we are seeing a lot of work in that area. There are many large architectural firms in this country who are paying attention. And in fact, at Salk Institute, we do have an organization called Academy of Neuroscience for Architecture. The idea is whatever we have learned from neuroscience, can we bring that to architecture? Because our brain resides inside built environment.

And whatever affects our brain can be, some of them can be designed into our built environment to improve brain health. The idea is very simple. So, for example, we all like high-sense. We don't know why, but our brain likes high ceiling, and that's a very simple thing that can be implemented. Similarly, the sense of light actually gives us a sense of time and sense of direction. So, for example, if you close all the windows in this office and you sit here, not only you lose the sense of direction, because now looking outside, I know which side is east, west, where the sun is coming, but it's also giving me.

a sense of time. Yeah. If we close all the windows, then I won't get the sense of time. And why this is important is if you look at many new apartment buildings and, you know, nowadays it's very hard for new the Gen G or the young people to actually buy a single family detached house. Most people are buying or renting or living in a high-rise building with apartments and they have very little light coming through. And on top of that, they put heavy curtains and blind. So there is no sense of light. There is no sense of time. And that is also driving why we tend to stay awake late into the night. Just imagine if you go to Vegas, most of the hotels, most of the casinos that don't have windows. Right. They don't want you to know. And once you are there, you won't know the sense of

You can stay awake throughout the night if the lights are on. And they keep on bringing you food or drink or whatever. They will bring you food and other thing. So that's why it's very important to understand how sense of light, sense of time are interconnected that affect our circadian rhythm. And this is where new building architecture, new building design, which might suggest that you should bring X number of flux into the building for X number. number of hours will have. In fact, we are also working with various organizations that are involved in building design and also well-building code to now bring up this idea of circadian lifestyle encoded in building design so that there is a sense of light. People should have

access to light, period. And we know that a lot of people may stay indoor because of injury. or because of old days, they cannot go out. But they do have a right to light. Yeah. And can we implement building codes so that they have access to light? Even though, you know, we have so many things that are controlled by remote. And I always wonder, how can you not build a very simple cotton that can be remote controlled so that somebody who has a injury and is bedridden, at least press a button and get light.

These all sound like such simple interventions, but as you mentioned, accumulated over a period of time in our life and our human life, starting from ICU, you know, all the way, you know, I mean, sorry, from the NICU, all the way down to the ICU and in between, these simple things have such a profound impact. Yeah. And as you mentioned, we're only scratching the surface right now. Yeah. Of how deep it goes and what's possible for us when we are reconnected to the earth,

which means having. regular exposure in any way we can. We're not going to go back to the Paleolithic age. No, no. In any way that we can in the modern age to help our body actually live in harmony the way that it was designed to do. Yeah. And also come up with better ways to when we fall sick, another thing that we haven't discussed is the timing of medication, timing of surgery, even timing of vaccination, all of these are linked to our circadian rhythm. So there are studies showing that those who have at least one week of good sleep before getting a vaccination

has much better response to vaccine. And this is important because as we get older, almost everybody should take the flu vaccine. At least I take flu vaccine every year because I used to get, I used to fall sick. I travel a lot and then I fall sick. And I tend to, I have become a true believer of flu vaccine because when I take the vaccine and if I get cold or flu, it's not that severe.

I used to be knocked out for a week. So I make sure that when I at least at Salk Institute, they used to give us flu vaccine at work. And we had to schedule that. I remember I used to schedule it so that for the past 15 days I was not traveling. And I take the vaccine. Of course, in the morning, because there are also studies showing vaccination in the first half of the day is much more effective in kicking in faster and with a higher tighter than the same vaccine taken in the late afternoon or evening. And, you know, there are many old people who have to be vaccinated against flu. There are a lot of people who are going to travel in three to four weeks.

and the country they're going to travel to that may need vaccination against yellow fever, all types of bad things, parasitic disease. And in that case, everybody needs to figure out what is the best time, what is the best lifestyle. And this is where having good night of sleep for the last five or seven days and then scheduling your vaccine in the morning is something everybody can do. And this is where, you know, it's not that it may give you a, superpower but at population level when you're when you are vaccinating a million people and 10,000 of them may get sick we can reduce that number to 5,000 or 4,000 or a

thousand and those who are falling sick may not get that severe disease so this is one area where again something can be implemented much faster the other area is chemotherapy so there is a vast literature dating back to 80s particularly for breast cancer, certain chemos work better in the morning and other chemos work better in the afternoon. But those studies were done on a small number of patients and they have not been done on large number of patients in multiple clinical centers, which is essential. And this is where, you know, some funding bodies should come in and then say, okay, let's go figure out when is the best time to schedule your care.

chemo relative to your past sleep wake cycle. But what is also known is women who have breast cancer, if they sleep regularly get sufficient sleep, then they respond to chemo much better and also their prognosis is much better. So this is another case where people can pay attention to their current habit of sleep wake cycle, at least from patient perspective that can be implemented right now. And in future, we can look into the optimum timing of chemo relative to your sleep wake cycle or eating fasting cycle, because as we know now, these days, your eating fasting cycle has much bigger impact on circadian rhythm in all these tissues than even light, dark cycle. It's just fascinating because I feel like we're in this time period. You know, and you were

a few months ago, you were on the Huberman podcast, and he's done a great. job with this. We're in this time and place in life where if we're going to help wellness become mainstream, it has to be what are the things that are low cost, no cost? And what are the things that everybody, sure, not everybody in every situation, there might have to be some navigating, but with some navigating and with the help of society, some public health measures, et cetera, that generally we should be able to create a society where these things are all possible. It shouldn't be that we have to only rely on drugs. that there aren't great reasons for drugs, you know, or that everybody has to have access to

these therapeutics or whatever it is, but that these basic things can fundamentally create an incredibly healthy society. Because right now, we're seeing this divergent society. Some people, because they're able to do these things, they have the knowledge, they have the access, they listen to podcasts, they're getting very healthy, very resilient. It's a small percentage of the population. And then everybody else is getting very unhealthy, very overweight, very very obese, type 2 diabetes, you know, I was reading the statistics by 20, I think it's like 20, I forgot the exact number. We'll look it up.

We'll put in the show notes. But how many Americans would have two to three chronic diseases, you know, that they're dealing with, diabetes and Alzheimer's or, you know, whatever it might be. So it's very scary, but it's very hopeful because until now in this modern day information age that we're in and you've done such a great job about it you know you write books you go on podcasts you never could hear from researchers like yourself right and maybe if you go and you see maybe if they were lucky a thousand people read their study yeah yeah right now more people have access to this and we are all the change that is setting up a different future you know standing on your shoulders of people like you

that are actually doing the work of it um but it's it's incredible what is possible there's still a lot of work to And as you mentioned, many times, we're just barely at the surface. But I definitely feel more hopeful than ever that we can create a different society than exists right now, a society of disease. It's almost like if you wanted to create disease, we would, if you wanted to create a world where everybody got disease, you'd be doing exactly what we're doing. You'd have them eat any time they want to all the way up to midnight, midnight snacking, chips, ice cream, no restriction on any kind of calories, all this majority of calories from,

you know, liquid calories. or ultra-processed foods, their sleep is messed up, they're not exercising, they're sedentary. That's the perfect recipe for disease, and that's exactly what we're doing right now in our society. And we have to wind back from that. Yeah. I completely agree because you said succinctly that these days it's not our genetic code that determines our health. It's the zip code where we live. Yeah. Because unfortunately, if you live in a zip code that doesn't have access to healthy food and you are also likely to be engaged in shift work because there are some zip courts where the socioeconomic conditions are so bad that people have to commute an hour each

way and then they are mostly working in shifts or they are doing gig works and that type of work is disrupting this very foundational balance in their sleep, wake cycle, eating, fasting cycle. So in that way, circadian rhythm research or its applications also address one of the fundamental issues with health care, that is the inequity. So it will actually sense the same, if you're poor or rich, it doesn't matter. You can't benefit from sleeping for seven and a half hours. So that's one thing. And second thing is, can you create that opportunity for health? and this is where public policies get into play.

We have not even touched shift work, people who work day and night shift or night shift and day shift. All those shift work schedules are built around convenience of the manager or few people who decide that this should be our shift. And for example, I live in San Diego, it's kind of interesting to see. San Diego City government has different departments or different arms. have different shift schedule and it happens in every city one department may for

example police department maybe they're adopting day shift sorry swing shift morning shift and night shift and the cops have to stay in one shift for three months before they go to a new shift whereas in the same city you might actually find healthcare workers are actually going back and forth between day and night shift in the same week. For three days, they may have to work in day shift, and for one or two days, they may be working in night shift, or the, you know, ambulance drivers. So they are also on different, their shift is actually changing very frequently. So when we think about modern lifestyle, it is made possible because of shift workers. Absolutely, we owe them so much.

But we haven't standardized their work hours. We, We talk a lot about 40 hours work week, 30 hours work week, whether we should start at 9 o'clock or 8 o'clock or time. And we should end. We never talk about shift work. And this is one thing where it actually affects a lot more people than we think because in the U.S. one in five people are shift workers. Yeah. And then there is secondhand shift work because the spouses and family members of shift workers,

they are also affected by shipwork because they're trying to be more caring, loving, inclusive. So they want to give company to this person. They'll stay up for the partner. They'll wake up early, go to bed late. Yeah, and those things affect everybody in the house. It also creates a culture of bad health because when the kids think, see,

means I remember when my, I grew up with my maternal grandfather who used to occasionally do night shift work and I used to think, oh my gosh, he's just superhero. He can stay up all night. And then later on, later in life, he actually had dementia and passed away much earlier than my paternal grandfather who lived in the farm and did not have much access to modern

day health care, but he kind of had a strong circadian rhythm. I don't remember him staying awake till midnight any single day. So this is one area where if you're thinking of slow. Standardizing. Standardizing. Which one of those is more, if somebody has to shift work and they need to advocate for themselves, and there's many situations where people can't, they just have to do that. Two questions about that.

Which one is more detrimental? Is it more detrimental to, you know, the nurse example that you had or the cop that has like, you know, you mentioned in health care, right? So that's one example. You're sort of two days a week, you're working, you know, at night and then the rest of the week, you're normal. or is it the cop schedule where for three months you're doing sort of the shift work and then you go back to the normal one? Which one is more detrimental to the body?

Actually, this is a politically very sensitive issue. And since we don't have objective data, it's really hard to say. Got it. What is? If you had a guess? I mean, there are challenges with each of them. So, for example, you know, when we talk about a lot of issues with cops. another stuff, but we never ask a simple question, how long that cop was awake before he or

he made that bad decision. And, you know, we always think that, okay, so this cop should have been more careful and all that stuff, but sometimes they have been, it's not only that one work, even though they may be in night shift, we are assuming that they might have slept during daytime, but they have a regular family. They have to take the kids for parenting. features as a meeting or something else. So sometimes it's very difficult for them to actually get that restorative sleep,

even though they are in night shift for three months. But their lifestyle has changed so much that they end to stay awake throughout the night and they have to be vigilant. They may be consuming three or four heavily caffeinated drinks. Right. So that even though they go home, even though they put all the curtains to make the room dark, they cannot sleep. And it does. We see that. But this is again a neck data. So this is where we have to come up with more objective study to see what will

help. We have done one study with San Diego firefighters. And firefighters, 70% of firefighters in this country, they work 24-hour shift. So that means they will come in at, say, in San Diego, they come in at 8 o'clock in the morning and their shift ends the next morning at 8 o'clock wow and but at the same time firefighters particularly the firefighting community and the carrier firefighters because there are 250 000 roughly 250,000 carrier firefighters in the u.s 700 to 800 000 part-time firefighters or volunteer firefighters but the full-time carrier firefighters the number one cause of death or death or death disability on work is heart disease or stroke. It's not getting injured from fire. It's heart

disease and stroke. In California right now, the number one health issue is actually cancer because they're exposed to so much of toxins. Chemicals, right. Chemicals and so much of stress that maybe their body is not ready enough to fight all that assault, all that stress. So we did this study where we asked a very simple question that can the firefighters adopt a 10 hours time restricted eating? And, you know, we always, when people hear intermittent fasting, they think 16, 8, 16 hours of fasting and 8 hours of eating, and that debts back to our 2012 study where we showed mice that eat within 8 hours, even though ate very bad food, junk food, that had high fat diet. fat, high, sucrose, all this diet, they were resistant to many diseases.

Yeah. Just to share that because we didn't go into that pivotal study that you guys put out there. So even the mice that were eating a terrible diet, as long as they were doing within those eight-hour feeding window, they didn't have all the downstream effects that you would expect with a terrible diet. Yeah. Right. Yeah.

And again, it's mice. It's mice. But that formed the basis. That formed the concept. That formed the concept. Because we published it in May. And by December, there are books published on eight-hour diet intermittent fasting, people talking about it. And I was scared because I used to go to conferences and people used to ask me, should we do it?

And I said, only if you have a pet mouse and you love your pet mouse, maybe you can do it because, you know, I don't want to go and tell people to do it. And there is adverse effect. But the bottom line is the reason why we did eight hours was, you know, that. time Christopher Balmars who is who actually he and I started this experiment ourselves so in the week days he would go feed the mice for eight hours and in the weekend I would come and feed the mice for eight hours during we reverse the light dark cycle because mice are nocturn all they're supposed to eat at night so when it was day for us the mouse room was night and we would change cages so tens of cages and you have to take out every mouse gently and

transfer them to feeding case to fasting case and fasting case to feeding case. And there was a lot of manual work. We still do it the same way because we actually get to see the mice how they're doing. If they're injured or they're not eating, they don't know. But the reason why we did eight hours was two. One was when we fed the mice for eight hours, we realized that they were eating the same number of calories as our control mice who had access to food 24-7. So that means these mice were eating the same food, same number of calories. The only difference was this eight hours.

The window. The window. If we reduce it to six hours, four hours or seven hours, then they would eat less. And if any health outcome comes out, then we cannot figure out whether it's due to narrow eating window or eating less. Because we know reducing calories also have been. The second reason, why it was eight hours was pure convenience. You have, since you are supposed to be in work for nine to ten hours, so eight hours is a good spot. And people thought, even now people believe that intermittent fasting means you have to stick to eight hours.

Right. But in subsequent papers, we have actually gone back and systematically tested eight, nine, ten, eleven, twelve, up to fifteen hours. And in mice, what we have seen is eight, nine, and ten have very similar health benefits. So that means mice can eat for nine or ten hours every single day or nine hours, ten hours for five days and two hours cheat day. They get a lot of benefits. And in humans, although people talk about eight hours intermittent fasting, in some studies where we started telling people you should be eating for eight hours, they'll start with eight hours. And after six or seven weeks, they will drift towards ten hours. So we realize that ten hours is a sweet source.

spot where a lot of people can do it because in that way they can at least accommodate having a breakfast with their spouse, maybe late breakfast or an early dinner with their family members. So they can comply or adhere to this habit for a long time. So that's why we did this 10 hours. And that's why we asked firefighters. And this was a very high risk project because first thing, the city. was skeptical that if you ask firefighters to eat only for 10 hours, will they have energy at night time to respond to calls? Because, you know, when you are, when firefighters saw off, even 30 seconds

led to an incidence, that's life and death, a millions of dollars in property value vanishing. So it's a high risk project. And second, the firefighter union, is also mindful about their members' health. I said, well, does it have any adverse effect? Because if it has, for example, if the firefighters' immune system deteriorates, or if they are more prone to injury because people think that if you're not eating, well, you may not have strength. You cannot climb the ladder.

You cannot fight. So there was also that kind of risk. So that's why this study was actually done with a lot of you know, risk from the city, from the fire chief, from the union leaders. And also we had an oversight committee from federal emergency management agency or FEMA. And they want to make sure that what we are doing is not going to harm the firefighters. And what we found was very interesting because this was a study where anyone, any firefighter, could enlist. They don't have to have a bad health condition. They didn't have to have diabetes,

obesity, or cardiovascular disease. So we had a mix of healthy and also not so healthy firefighters metabolically, but, you know, the bottom line is all firefighters have to have to meet some physical activity criteria. And they were all in that way, they were all able-bodied firefighters who were fighting that really the superheroes of the society. So that's why he called it the healthy heroes study. And there are 150 firefighters. And this is an example where we also learned a lot about the stressful life of firefighters. We actually embedded ourselves in the busiest fire station. We did many of my teammates, particularly Emily Manugian, who is the first author in this study, she went and spent 24 hours in the busiest fire station in San Diego.

And she experienced 10 calls that night. Wow. Just imagine, even though she had access to, she was assigned a bed so that she could sleep there. Just like any other firefighters, she had to get up when she heard the beep and put on her shoes and a jacket, she was and helmet. And she had to run. She was assigned a specific fire engine and a seat. She had to get into that seat and sit there, just like other firefighters. and go to the incident side, she has to get out of the truck and stand there.

Of course, she was not fighting fire, but stand there. Right. And then come back. That happened ten times that night. Wow. And then the next day she came back. She said, I don't know how these guys are actually still alive. And I don't think our study will be helpful because there's so much stress.

I don't think that they can actually cope with it. Yeah. How is time restricted feeding going to be helping at all amongst all the stress? they're dealing with. Yeah. And then she said that, well, when they're getting out at 8 o'clock, and I see also, she also got out at 8 o'clock, she said, well, you know, in the beginning, I was also at an event that, well, you should not drink coffee outside your eating window. And then she said, there is no way I can ask the firefighters not to drink coffee, at least for public safety, because I don't want these firefighters to drive home, sleepy.

Totally, totally. So that also helped us a lot about. the stressful life they have because a typical firefighter sees really bad things in a single day than what we see in our entire lifetime. Yeah. And although she did not go to the side, she heard what happened. And so amidst all that stress, we know that we are always told and we always think that when we are stressful, then we cannot adopt healthy lifestyle. So she was very skeptical.

skeptical. Even my clinical collaborator, Pam Tov, who oversaw the whole project and she was really crucial in making sure that all the clinical blood test and everything is done well. Initially, we thought that we are destined to fail. And we also tapped on to something the firefighters actually have. They have a very strong sense of community, strong sense of sisterhood and Brotherhood and they realize that this is not a regular study because in clinical trial.gov, this is a website that lists all the clinical trials ever done. There are 420,000 clinical trials ever done in 110 countries and less than 100 of them. Actually, clinical trials to improve the health of shift workers. So one in five,

adult works and shift. And shift work increases the risk for many of the disease. So they have the, they carry disproportionately large burden of disease, but less than one percent of studies. Looking into how to improve their lives. Yeah. So when the firefighters actually heard about it, they realize that whatever we find, first thing is this is almost once in a, in their lifetime study. And second, whatever we find that might help their brothers and sisters, 250,000 active duty firefighters in this country alone and internationally maybe a few million firefighters in figuring out whether this 10 hours time receiving gives them any help. Some form of extra resilience amongst all the chaos that their lives live in.

Yeah. So that's something that we really appreciated because many times people who are part of the clinical trial, they may or may not know that whatever they are doing is going to affect the health of millions of people. Yeah, they don't, it's not always clear. It's not clear, but this is a greater role that they play. So that's why I am always very respectful. I have huge regard for people who actually volunteer that time to be part of any study. Yeah. And, you know, what did you guys find? So what we found was, yes, it is feasible. And, firefighters who actually did this 10 hours time restating. We had 75 firefighters doing 10 hours.

75 could do whatever the regular standard of life they're living in. So one thing is it's feasible. So it did not reduce the quality of their work. They still were able to perform. Yeah. So that performance was perfectly fine. And this study was done during COVID. So majority of the participants actually signed off after months. March 2020. And this is also the time when in California, we had two serious fire seasons. Yes. And that means many of these firefighters were actually called in to fight fires for two or three weeks.

And when they're fighting fires, of course, we ask them, don't think about this study. Just eat whenever you want to energize yourself. So there was a lot of stress. And they're responding to COVID-19 calls because there are the four, four. front. And what we also found was the time restricted eating group. We had battery of test. One was their brain health or mental health. And what we found, those who did 10 hours time restricting, their brain health, their ability to absorb this emotional stress at work sustained throughout this study. Whereas this control group were also exposed. to this COVID-19 and related stress, their brain health deteriorated during that study. So this is a huge thing for firefighters because a big chunk of firefighters actually deal with stress and almost like PTSD kind of stress because just imagine when we drive to work at every intersection

every time we think about, oh, this is the store where we get this candy or that donut, this food and all that stuff. When a firefighter drives to work or anywhere in the city, since they live in that community, they serve that community, there is a constant reminder, oh, at this intersection, there is this terrible vehicle accident. That house somebody committed suicide, I could not save. I was late. That house born down and I could not have.

So that stress is always every single hour of their wakeful hours when they're outside. They are getting that stress. And this is something that we don't talk about because we think that, okay, so firefighters they go and come back. So this is another thing that we learned how much stress they go through. And for them to adopt this 10 hours time receiving was a miracle because we thought that they did it. In fact, they did it. All the stresses over there.

And then when we look at it, it looked at all. at the firefighters who started healthy, they stayed healthy because many times we think that even nowadays I hear, okay, if you're healthy, maybe if you eat within 10 hours, you lose your muscle mass, many bad things will happen and all that stuff. No. Actually, these people stayed healthy, their performance did not decrease and of course firefighters are very mindful of their food. We also give this advice that everybody should follow a Mediterranean diet because the control group, you just cannot say that. You just go and do whatever you do. We give the Mediterranean diet cookbook and then they actually improved their diet because they also used our Mice

Acadian clock app. So they took pictures or the logged what they were eating. We actually saw there was a significant increase in their fruits and vegetables intake. And to our surprise, this was not intended. We saw that the time-rested eating group reduced their alcohol intake. And this is, again, a big thing for nighttime shift workers, particularly firefighters, because they have so much stress that they actually go find relaxes and alcohol. And in fact, reducing alcohol intake is the active area of research for firefighters and even active duty military or those who recently retired. And now in retrospect, it makes sense because if they're eating only for 10 hours, they don't have much opportunity. because the bar closes at seven or eight. And this is another benefits we saw for everybody,

those who were drinking at baseline. And then those who had high blood pressure that reduced, including systolic and diastolic, because diastolic blood pressure, the smaller number in your blood pressure reading, that's actually difficult to reduce with even blood pressure medication. And we are pleasantly surprised that that reduced. Then those with high cholesterol,

we also saw the cholesterol levels decreased. significantly, those who started high. And then high sensitivity CRP, which reflects inflammation because firefighters, they're exposed to so many bad things. I mean, what I also learned is less than 25% of the calls are for fire. 75 plus percent calls are for medical emergencies. So that means they're actually taking sick. patients who may have infectious disease, sometimes they sneeze, sometimes there is. So one firefighter said, yeah, when you are in duty, if something falls on your skin, it's wet, yeah, that's some

bacteria or bug or something. That's really nasty or virus. And then if you smell something, that's odd, that's cancer, because most of the things that burn also that fume has a lot of toxin. So to see that the CRP level also significantly decreased is a very nice sign that maybe their inflammation is also reduced. So for these firefighters, these were specifically shift working firefighters. So typically what time was there eating window? When would they typically start? This is also another thing.

We asked them to self-select. Self-select. 10-hour window. And what we found is most people selected a time window that starts somewhere between eight and 11 o'clock in the morning. Okay. So they were not skipping breakfast. This is very important.

They were actually eating a very healthy breakfast, either at eight, very few at 7.30 or 7.30 or 7 o'clock, but the median was somewhere around 9 o'clock or something. And they would eat their breakfast and then they would have actually a lunch because another thing with firefighting community, at least in San Diego, is they tend to cook at fire station. And sometimes they can eat during lunch, and sometimes if there is a call, they will go and come back. And then they would have a little bit food for dinner around 6 o'clock. So in that way, what we found was, surprisingly, when they were at work, they were more disciplined about their food.

Versus when they're at home. When they're at home. Because you're doing it with your brotherhood, your sisterhood, everybody's supportive. They're pushing each other. Yeah. And this is where the social aspect of doing it is also important. And particularly what we find is, and this relates to household. If the person who is making food and serving food, whether it's the male member of the female member of the household, if that person adopts a healthy lifestyle, then that creates a culture within the family.

And here, within the firehouse, we started a culture and that actually propagated very nicely to the extent that some of our control group actually towards the end. they were doing time-restated eating, which might have reduced some of the difference in effect because we also saw many of them benefited. So this is one example where, you know, we did this study. And even till now, many firefighters contact me and saying, well, how can we help you to disseminate this to all the firefighters within the union and also through International Firefighters Association, International Association of Firefighters. And luckily, a few years ago, I was on a podcast with Rhonda Patrick and another philanthropist actually reached out to me saying that, okay, so I'll help you to disseminate this. Oh, wow.

And with that funding, we actually, luckily, I've been extremely lucky to be in Salk Institute because we had a videographer, Mike Jeff. and that time, he wanted to do something interesting because he wanted to go to film school, get his degree, and they said, hey, can I follow your firefighters? I said, yeah, you can follow, but you cannot tell me which firefighters you are following because that would influence the study teams monitoring of those firefighters. So he followed four or five firefighters throughout this time-resating journey,

and he took various video footage, interviewed them and then he came up with 19, 20 minutes of a sort documentary. And then we showed it to firefighters. And then they said, wow, this is really cool. Can you expand it so that you can have more stuff about firefighters? So I went around. Making the documentary, it kind of inspired a bunch more people. Yeah. So I went around and then at the beginning of the pandemic, I went interviewed a few firefighters in other parts of the countries and then we put it together. So now there is a documentary called Healthy Heroes. We are now. Can we bring it up, Tessa? Is it their website for it? Or do people watch it where? So, and so far we haven't released

it. It's going through various, you know, film festivals. And luckily, we have quite a few Healthy heroes. Healthy heroes. And luckily, we have a few awards so far. Oh, that's great. That's great. So it'll be nice to release it later on this year. And where could people, if they want to stay in touch about like once it eventually releases, is there somebody they should? should follow or will you post it on Twitter? Yeah, I'll post it on Twitter. Yeah, I'll also the Institute will also post it. Well, besides it being a fascinating story, you know, what I'm getting is the takeaway from that, right? Very touching. And by the way, the fact that you and your team are doing that, it's incredible, right? As you mentioned, we have to support our shift

workers. They are really carrying the burden of so many aspects of life. Health care, police, firefighters, first responders, you know, truck drivers, truck drivers, everything, right? Yeah. Yeah. They are really powering what this country has available to itself. And the takeaway that I got from it is that even when somebody has to, right, my brother-in-law is a doctor, my, my other brother-in-law is a nurse, right? Yeah. You're going to, if you are in these professions, you're going to have to probably do some version of shift work. Yeah.

Right. Even if that's in your, you know, residency or whatever, even then still taking advantage of things like time restricted feeding, having a set feeding window, which is inspired based on the work that you guys have done, that can help give the body some sense of resilience. Yes. Right? So even amongst some stress, there's things that we can do that can help combat that stress. We shouldn't just throw up our hands and say it's all done.

Yeah. There's still some things that we can do in time restricted feeding is one of those things. Yes. Yeah. That's something that's very, I was skeptical from the beginning and now. Yeah, that's really beautiful. And then the nice thing is, you know, we always respect the firefighters and we also understand their life is stressful. Yes.

If they can do it, you can do it. If they can do it, you could do it. Yes. While we're winding down here, this has been fantastic. We've had a great conversation. I think we've almost gone, like, two and a half hours plus. This has been great. I mean, this is the power of being able to have a conversation in person.

So thank you for being able to come. And so you guys have also, you know, part of this is that you have your research app, right? You mentioned earlier. Yeah. And you also have another app that you guys have released, right? It's called On Time. On Time Health. Yeah.

Yeah. And Tesla, if we could bring it up. It's get on time health.com. Yeah. If we could bring that up. And you're trying to, you and your team are trying to make this simple for people. Yeah. That if we can practice and incorporate circadian biology into our normal.

schedule, which influences the time period that we eat, right? Time restricted eating, sunlight exposure, optimal movement times. Just those few basic things can make a radical improvement in our health. And that was the inspiration around launching that. Is that right? Can you add anything more to that, the context? Yeah, I mean, whatever we are learning from the research app, that's my circadian clock, what we learned is a lot of people can follow very simple things about the 24 hours schedule.

One is self-select beginning with, say, maybe 10 hours of eating. So choose a 10-hour feeding window. To begin with. Yeah. Yeah. What works best for you. And you can try it for a few days to figure out, okay, what are the barriers? is it your health condition?

Because sometimes some people might have type 1 diabetes or they may have, they may be on a drug that actually makes it worse to be fasting. So for example, type 2 diabetes who are on sulfonyluria, they may find it difficult because their blood glucose level can go down. So what we're finding is 12 hours to begin with, those who have those conditions is relatively safe because we haven't seen any adverse effect with 12 hours but at the same time 12 hours may not be optimum for many things

and then after one or two weeks you can reduce it to 10 hours to see which 10 hours works and then maybe for some people you can still go down to 8 or 9 hours at least for a few days or few weeks one thing is you have to have consistent breakfast first meal should be consistent because that fast meal, changing that fast meal is sending a signal to your circadian rhythm that it's a different day. It's the day starting at a different time.

What I call that causes this metabolic jet lag. Yeah. And then that's why you even recommend in addition to having kind of like shooting for a consistent bedtime to optimize sleep. That's why generally you recommend for everybody whether they're doing the app or not is that having a consistent sort of time that you break fast breakfast in the morning is just a good general practice for your body. It's breaking your fast.

It's not the first meal that you have to eat after waking up. People get confused because they're saying that, okay, so as soon as I get up, I have to eat something that's my breakfast now. It's the breaking of the fast. So you should have fasted for at least 14 hours to break your fast. And I think I've heard for you, you generally like to have your first meal around 8 o'clock. Is that right? Yeah. It's between 7.30 and 8.

7.30 and 8. And I work around six. Yeah. And I usually, I finish my breakfast at home. And then these days I come to love and then I have my coffee because I realize that, yes, if I can have coffee with somebody during my meeting with them, then we achieve two things. One is I've already done my breakfast and then that's an optimum time. So that's one.

So that we incorporated into the app, how many hours you're eating. Second is, as we discussed, brain health is so much important. Even those who don't have depression, anxiety or anything, just for your nighttime sleep. Getting outdoor, getting an hour of daylight. And this is not looking at the sun, just daylight, even if it's cloudy, even it's snowing, put on the right protective clothes and then get out. And then just get outside. Get outside. And then the afternoon exercise or 30 minutes of exercise, even if it is brisk walking.

I mean, you know, getting 150 minutes is not that difficult. I mean, many people can do that. 15 minutes here, 30 minutes here adds up over the course of a week. Yeah. So that will add up. And then avoiding light for two to three hours before bedtime, that's a huge thing because a lot of people actually don't think about light. And in fact, a lot of people that think that their room should be lighted because the reason is daytime they have closed their windows, put their curtains for privacy or other issues that they brighten up their daytime light.

And the same light continues towards late evening and light. Right, until they go right to bed. Right to bed. So this is another thing that one can do, very simple stuff. And what was that recommendation? Is that two to three hours before bed? Yeah. Dim the lights.

Dim the light significantly. Most people are not going to have a red light in their house, right? Yeah. I have one in mine. Yeah. And it's awesome. I start to dim the lights in the house. I'll turn on a red light in sort of the bedroom.

Yeah. And it's been really helpful because my wife, she would start to feel a little sleepy because I started helping her circadian biology. And the lights were dim before bed. And then all of a sudden she would go to her bathroom. Right. I have my bathroom. She has hers. She'd go to her bathroom. She'd turn on all the lights. And she'd start brushing her teeth and washing your face. And I'd be in bed getting ready for sleeping. She would come back and she'd say, I feel wide awake. Like I have all this energy. I just want to talk. Let's watch some TV. Let's do this. Let's do that. I'm like, yeah. Why do you have all this energy that I realize it's, she's getting this massive dose of light right before she sleeps. So we dim the lights a little bit. We turn the red light on. But even in general, I've heard. Yeah. And I think I heard this from Andrew Heberman. but he would say that even if you,

just especially like the overhead lights. Yeah. Right. Keep the lights that are sort of at eye level that might have a lamp, but then dim those as much as you can. Yeah. And you're saying the ideal window is like two to three hours before bed. Just make everything more dim in the house to prepare your body for sleep.

Yeah. Just like you need an alarm clock to wake up. You need a little nuts to go to bed. And since we are also on all digital devices, Another thing people can do is to switch on the night shift or nightlight feature in your Android phone or iPhone or your laptop. Even my laptop has the same. All laptops, all computers have that feature. And you just turn that on so that around, I do it around 8.30 p.m.

So 8.30 p.m. my devices are dimming down and they're also redshifted or orange sifter. So then I know. It's time. Because sometimes, you know, we don't keep track of what time it is. So this is like a nudge. Hey, this is time to wind up. And we'll link to it, but there's a manual feature on the phone. Yes.

That I'll just show you. Here's my phone over here. I'll send a link to how to activate it. It doesn't happen automatically like night shift. But you can hit your phone three times and then it goes to dark red. So it's even redder than the night shift mode. So it's a setting on Apple. I think Android has it as well too.

For the people that are listening, we'll put a link to a little blog post. where they can learn about that. And then do you also recommend, you know, the blue light blockers for people that have them? Yeah, so what I've heard is a lot of people actually find it helpful, but the blue light blockers, typically the good blue light blockers are funky looking. They're either yellow or red.

Yeah, mine look very red. Yeah. So then you know that you've got the real stuff, because when it blocks blue light, that means you should not see blue light but all other colors. And if you combine, say, red with something else, you'll get yellow, so that's a yellow or red. But there are a lot of glasses that are being sold

as blue light blocking. But that are not blocking. Well, it may be blocking 5% or 10% because there is no clear definition that there is no standard saying that this glass will reduce blue light by X percentage. Since we don't have that standard, then anyone can reduce blue light by 2%. 10% and say, this is helping.

Yeah, this is helping. So, for example, you can go to the, you know, to protect yourself from skin cancer, you can always say, I have SPF1. Right, right, right. Here's how you know it's a good blue light blocker. You should not, you should actually should be very difficult to use electronic devices because you can't, you don't actually know what you're clicking on because there's no blue there.

Yeah. Everything kind of looks the same. And if you're lucky, there's a little bit of texture you can kind of see. Yeah. But it's actually very difficult to use your. phone if you're using like true blue light blocking glasses because you can't really kind of distinguish between different things which makes it a little bit harder to use yeah and also you know if those who use it um even though they can wear blue light blocker and watch a little bit of TV

of course the TV is still going to be stimulating no no the TV images will be a little bit weird because you are taking away blue yeah but they report that they can still feel sleepy much better. And this is particular, you know, there are a lot of people who send feedback through the app

or they talk to me and this is where what I hear is older people, particularly. They find the blue light block are much more useful than younger people.

I put them on usually about like an hour and a half, two hours before bed. My wife, when she sees me put it on, she's like, I'm not ready to go to bed.

Take them off. Take them off because she knows that I put them on. And I immediately start to feel like relaxed and kind of sleepy. And if I'm not careful, like I end up falling asleep before her and she doesn't like that, right? Not to air my relationship, dirty laundry out there. But she's like, no, we have to put them on at the same time so we fall asleep. But yeah, I've kind of trained my nervous system in a way.

You know, and I don't sell any that are out there. I put them on and I immediately like my nervous system starts to feel like, like, okay, I'm getting tired now. Yeah. So that's part of the recommendation in the on-time app is just people starting to dim the lights and incorporate that and have that consistent bedtime. Yeah. So that's why there are four or five things that people have to check every day. So in that way, it's just a reminder.

Sure. Even the small things, what we are seeing is a lot of people, even me when I started, it's not that every day will be a perfect day. Right. But at least what happens is when we cannot sleep, And then we can go back saying, huh, I actually ate late. And this is one that I know perfectly for me. What will happen is if I eat after 8 p.m.,

my usual dinner time is around 6, and then if I have to go for dinner or some... Or like we're recording a podcast, it's 6 o'clock now, you're going to probably eat later. Yeah, then I know that that night my sleep will be bad. Yes. And I have to take some extra precautions. So, for example, I'll take a shower before sleep, bedtime, to further cool down.

So these things actually help us to really look at ourselves, how our habit influences our health. Just like having a mirror in the bathroom helps us to figure out, okay, so do I have to shave? I have to cut my hair, all that stuff. So similarly, these five simple habits, whether we did that or not, reminds us what. what to focus on. That's powerful. And there's simple things, right? But just as human beings, we're not always the best at tracking.

So that's where technology can be very helpful in that process. Yeah. Right? It can be helpful. Absolutely. Well, this has been fantastic. You know, I feel a little bad because you're probably going to eat late tonight. That's going to disrupt your sleep.

But in another way, I feel so honored that we got the opportunity to have this conversation because these simple tools, these simple lifestyle changes, starting with even just the first one we mentioned, not eating late. not midnight snacking, they can have profound impacts on our health. Then you stack that with a little bit of walking. You stack that with some extra strength training exercises that people can do those during the week. You stack that with dimming the light and getting a little bit of morning light. These things add up and you feel good.

And what I've found is that when you feel good, so many more things are possible in your life. And that's when you start to make a difference for other people too. If you don't feel good, it's very hard to long term be down. dedicated to making a difference in other people's lives, right? Which is why at the end of the day, we're all here. But when you feel good and you've taken care of yourself, now anything is possible. And I think it really does start with sleep. So I'm so glad we dedicated so much time to that.

If our audience wants to stay in touch with you and even make a donation to the Institute, what are some places that you want to send them to keep in touch? Yeah. So they can follow me on Twitter. That's where you're most active. I try to be active. And that's where whenever I see an interesting paper or something I want to share that wisdom, then that's where I share. Which I really appreciate.

I find out about a lot of the latest literature by following you on Twitter. Thank you. And for making a donation, actually, there will be a link. Hopefully you can share. So I think it's pander.org.org.edu slash giving. And again, these donations actually help us to do this very three things. one is think outside the box, do very simple experiment that can be done with three months, six months in the lab. Then second, start small human study. So, for example, I hear a lot

of feedback from people saying, hey, I know somebody who has PCOS and they tried time restating and they improve their health. But it's anecdote, going from that anecdote to a small study, 12 people, 24 people, that needs these small donations. Yes. So then the third one is, for example, I talked to you about the firefighter study. We collected blood samples from firefighters, at baseline after intervention, and we reported few things in the first set of papers, but we have their invaluable blood samples. Right.

Now the question is, can we go back? because now technology is advancing so fast. Now we can actually look at 7,000 proteins, including hormones and different things, the blood samples. And these kind of donations actually help us to analyze that blood sample for these different hormones, different proteins or metabolites. So, for example, one thing, again, this is out of these donations that came out was we took a small set of samples, and then we, we,

send this for metabolomics. So that means we can look at 1,000 different molecules. So there's glucose or it's amino acids, whether it's toxic chemicals produced by the gut and sent to the plasma, sent to the blood. And what we found surprisingly was people who do time-restricted eating, even though they did not change their diet drastically, the toxic chemicals that are made by the gut microbiome, and sent to the blood called TMAO. I will not go into detail, but that is now linked to different kinds of cancer. The TMA levels went down.

And now we are thinking, okay, so there must be a link with gut microbiome or how the chemicals are processed in the gut. So these kind of donations actually help us to go and even use some of the samples that are left from studies that are funded by the federal grant to explore,

New Frontiers. Yeah. Oh, that's super powerful. Yeah. Well, we'll have the links to all those in the show notes as well as your books. There's circadian diabetes code. There's circadian code in the show notes. Sachin Panda, thank you so much for coming on the podcast and sharing your work with the world.

Thank you and have a perfect circadian day.