Feel Better, Live More with Dr Rangan Chatterjee - #27 Why We Sleep with Matthew Walker PART 2

Episode Date: July 17, 2018

Dr Chatterjee talks to world-leading sleep researcher, author of the international best-selling book Why We Sleep and Professor of Neuroscience and Psychology at the University of California, Matthew Walker. They discuss everything you ever needed to know about sleep in this 2-Part interview.  In Part 2 they discuss how sleep affects every aspect of our health – how sleep deprivation can affect our blood sugar levels, increase our risk of heart attack and impact our mental health. They discuss alcohol’s impact on sleep and the staggering financial costs associated with lost sleep. Finally, Matthew provides his top tips for optimising your sleep. Show notes available at drchatterjee.com/whywesleep Follow me on instagram.com/drchatterjee/ Follow me on facebook.com/DrChatterjee/ Follow me on twitter.com/drchatterjeeuk Hosted on Acast. See acast.com/privacy for more information.

Hi, my name is Dr. Rangan Chatterjee, medical doctor, author of The Four Pillar Plan and television presenter. I believe that all of us have the ability to feel better than we currently do, but getting healthy has become far too complicated. With this podcast, I aim to simplify it. I'm going to be having conversations with some of the most interesting and exciting people both within as well as outside the health space to hopefully inspire you as well as empower you with simple tips that you can put into practice immediately to transform the way that you feel. I believe that when we are healthier, we are happier because when we feel better, we live more. we live more. Today's episode is going to be the final episode in season one of my Feel Better Live More podcast. No need to worry guys, the podcast is going to be continuing, but it's been

an incredibly busy year and I've decided to take a break over the summer and spend some downtime with my family. Since the launch of the podcast in January, I've managed to release a brand new episode every single week for almost six months now. And I've decided to take some time this summer to reflect and relax and think about how I can make this podcast even better and more relevant and inspiring for you. If you get a minute to go to drchastity.com forward slash survey, I'd be incredibly grateful. It's a very quick survey that's going to help me understand what you think of the podcast. It will also help me determine what would be the best way to move it forward. So guys, maybe at the end of this

episode, if you have a couple of minutes spare, if you could go to drchastity.com forward slash survey and give me some feedback, it will help me come back in September with a brand new and a much more exciting podcast. Today's episode is the second part of my conversation with world leading sleep researcher and author of the fantastic book, Why We Sleep, Professor Matthew Walker. Now in the last week's episode, we discussed so many different areas to do with sleep. We discussed jet lag, how caffeine affects your body clock, how sleep can help you lose weight, and even how athletes use sleep to enhance their performance, and so much more. If you have not listened to last week's episode yet, I highly recommend that you go and check it out now before you start listening to today's episode,

which is part two of my conversation. At the end of last week's episode, Matthew tells me how since the 1940s, we have lost about 20% of our sleep and how devastating the consequences have been on our health. We pick up the conversation today just after I've been telling Matthew how as a doctor I'm always incredibly passionate about lifestyle changes because not only are they harmless they also affect multiple different pathways and organs in the body rather than just one. I love what you're saying that you know know, in medicine, we're often or even in research and pharmaceuticals, we're often trying to sort of manipulate one pathway in one area of the metabolic system or one aspect of the immune system or one feature of the cardiovascular system. And, you know, sleep affects all of those. And we can, you know, I'll give you an example.

give you an example. Firstly, we know that if you get a patient and you have them sleeping just six hours for one week, this is someone, let's say, who is healthy. At the end of that one week of short sleep, their blood sugar levels are disrupted so significantly that they would be pre-diabetic, that you would diagnose them as being in a state of pre-diabetic. Just from sleep deprivation. Just from sleep deprivation. We control all of the factors. You can also speak about sleep loss and the cardiovascular system. And all it takes is one hour of lost sleep because there is a global experiment that's performed on 1.6 billion people across 70 countries twice a year. And it's called daylight savings time. Yeah. savings time. And it turns out that when you look at that data in the spring, when we lose an hour of sleep, we see a subsequent 24% increase in heart attacks as a result. It's just incredible.

But in the autumn, you know, when we gain an hour of sleep, we see a 21% reduction in heart attacks. So the data's there on a global level, isn't it? Just from that. It's striking, you know, and you can even think, you know, you speak a lot about, you know, the immune system. It's so key for our health. So tell us, what does sleep do for the immune system? So firstly, we can look on both sides of the coin. What happens when we don't get enough sleep?

Firstly, we know that people who are sleeping five hours a night are four times more likely to catch a cold than those people who are sleeping eight hours or more. Wow. Striking study, very well controlled study. We also know that it doesn't take one week of short sleep deprivation. One night is enough. What we've found is that if you take healthy individuals and then we limit them to just four hours of sleep for one single night, what we see is a 70% drop in critical anti-cancer fighting

immune cells called natural killer cells, which are these wonderful sort of immune assassins that help decrease our cancer risk. Yeah. And help us fight infections. And fight infection. Part of our innate immune system. Exactly. Part of that critical innate immune response.

Flip the side of the coin. And now what we find is that when you get sleep, there is a change in what we call the autonomic nervous system, which is sort of this automatic part of our nervous system. And that automatic nervous system is split into two branches. One that is sort of like the accelerator pedal that gets us revved up, triggers the fight or flight response. The other is the break that sort of calms us down. And when we go into deep sleep, we apply that break to the nervous system and everything quiets down. Heart rate decreases. Deep sleep is the most wonderful form of natural blood pressure medication that you could ever wish for.

But one of the other things is that we see as that nervous system quiets down, levels of things like cortisol drop down, that stress-related chemical. And it's during that time that the body goes into an immune stimulation mode. And it's where essentially you're going to restock the armament of your immune army so that when you wake up the next day, you can battle and fight infection. What's also fascinating, and I love this data, and this tells you just how critical sleep is to a fighting for our health. If you look at people who become infected or you actually infect them in the experimental laboratory, let's say with sort of a cold vaccine, you immediately trigger increased sleepiness and increased amounts of deep sleep. And it turns out that the infection indicates to the immune system that you're under

attack and the immune system will actually signal to the sleep system within the brain, we need more sleep. Sleep is the best battle force that we have right now to combat this assault. And so that's why when you're sick, all you tend to want to do is just curl up in bed and go to sleep. The reason is because your body is trying to sleep you well. That's an appropriate response to what's going on, right? Exactly. The bodies are pretty clever, right? They are remarkably clever. You know, again, Mother Nature has figured this out. And so she

brings up this thing called sleep, which I would argue is probably like the Swiss army knife of health. You know, whatever ailment you are facing, it is more than likely that sleep has a tool in the box to try and help fight it. That's so key. Whatever ailment you're facing. Guys is more than likely that sleep has a tool in the box to try and help fight it. That's so key. Whatever ailment you're facing, guys, if you listen to this, whatever you're suffering from, whether it's a lack of energy on a day-to-day basis, whether it's that you're worried about your risk of developing a chronic disease such as type 2 diabetes or heart problems as you get older, know what Matthew is saying what Professor Walker is saying is that sleep improving your quality of sleep is going to help you with all

these different facets it's going to help reduce your risk it's going to help increase your energy it's also going to reduce your risk of actually getting disease in the future which is just absolutely incredible I mean we are going to move on to tips, because I know many of you will be thinking, okay, this is all great. You know, I'm sort of hearing about all these things that sleep does, but how do I get more? So we're going to come to that shortly.

But so much I want to talk to you about, Matthew. I mean, I think we could easily make this like a full day podcast. I'm that fascinated in this. I'd love to return at some point, should you wish me to. Yeah, well, 100%. But I think, you know, what you said about medical school training, I think it's very important because pretty much everything that I put in here

and then the last quarter of the book is on sleep. I'm not convinced that any of that came from my medical school training. So that was all self-taught from spending hours on PubMed, reading research, going to conferences, trying to learn more because I wanted to help my patients more. I thought, I need to know more about this so I can actually do my patients, give them a better service. So you're saying that maybe medical students may get maybe two hours or so and you'd love to sort of try and help that and get you know maybe a sleep curriculum into

medical schools and this really you know i think one of the reasons we get on so well is there's so much synergy in our in our viewpoint in terms of how we think this needs to change so what i've done over the past six months is is develop a brand new course with a colleague of mine dr panjir called prescribing lifestyle medicine and it's a one-day masterclass to teach healthcare professionals but primarily doctors on the basics of you know lifestyle medicine if you will as a term you know so we go into sleep and we we teach this framework while they can simply apply these these four pillars with their patients to start to actually implement lifestyle medicine i'd love to you know i'd love to maybe collaborate with you and show you the slides i'd love to, you know, I'd love to maybe

collaborate with you and show you the slides. I'd love to. And I've got, you know, I teach a whole course at the University of California, Berkeley, the science of sleep. So I've got lots of slides. I'd love to just share and do whatever I could to try and help sort of perpetuate that movement that you've got going. It's wonderful. That's exactly what we need. Yeah. And then maybe we can talk about how we get that into medical schools and, you know. going. It's wonderful. That's exactly what we need. Yeah, and then maybe we can talk about how we get that into medical schools. Yeah, I was going to actually ask you, how could we even collectively think about

trying to approach medicine here in the United Kingdom and see if we could try to enhance that? We'll talk about that off-air from the podcast because I think that could be a great collaboration. Okay, Matthew, I know you're short on time and again, we could just go on for so long. Claire from the podcast, because I think that could be a great collaboration. Okay, Matthew, I know you're short on time. And again, we could just go on for so long. I was going to ask you about sleep and stress.

But I think, you know, guys, for those of you listening to this, I cover that in quite a bit of detail, I think, with you on my chat that's on my Facebook page, which is facebook.com forward slash DrChattergy. So, guys, you can actually check it out there but everything that Matthew and I talk about including that Lancet paper that he mentioned is going to be in the show notes which is going to be at Dr Chatterjee dot com forward slash why we sleep there's going to

be links there to everything Matthew talks about some of Matthew's articles his book all kinds of things so guys do check that out after the podcast and you can do a bit of further reading on those topics that interest you. So yeah, where to go to next? I mean, one thing that we do talk about on that course, and I think we've not spoken about this yet, is about sleep and its role in mental health. And what's interesting, you mentioned bi-directional relationships before and how a lack of sleep can increase our risk of problems, but also sleep can be a treatment as well for various things. And I wonder if you could talk about that in relation to mental health problems such as anxiety and depression and maybe from there just move briefly onto Alzheimer's if possible.

Yeah. So we've done a lot of work in this area of sort of sleep and mental health. I think the first point to note is that we have not been able to discover a single psychiatric condition in which sleep is normal. Wow. And I think sleep has a profound story to tell in our understanding, in our treatment, maybe even ultimately at some point our prevention of grave mental illness. And I don't say that flippantly. Firstly, we've done some work where you can take healthy individuals and you can deprive them of sleep for a single night. And then you place them inside an MRI scanner and you look at how their brain has changed. And what we find is that these deep

emotional brain centers erupt when you're sleep deprived. You become a lot more emotionally reactive, impulsive. There's a deep brain center called the amygdala, which is one of the centerpiece regions for the generation of strong emotions. That part of the brain is up to 60% more reactive when you're sleep deprived relative to when you've had a good solid night of sleep. And we've also found out- That's a huge amount, right? It's a 60%. It's very difficult to usually see that type of a change in the brain without some kind of pathology or drug. Sleep deprivation will do it. I think on an intuitive level, most people recognize that when they haven't slept well,

they're just a little bit more reactive to things that that email from a boss from their boss for example can be easily misinterpreted you know they annoyed at me they you know you suddenly start to see things that aren't there and i i've just i mentioned this before i've just completed my second book called the stress solution which is going to come out in january and i cover a little bit of this that you're talking about in that to really try and show people that you know lack of sleep is a stress on our body and 60%, that's incredible. Change in the brain, yeah. And I think it really comes, you know, you're absolutely right. Many of us have a sense that, you know, I just snapped, dot, dot, dot. You know, those are the words that usually follow a, you know, bad night of sleep or

when you've not got enough sleep. And we know it all the way down sort of the age chain. You know, you think about a parent holding a child, the child is crying and they look at you and they say, well, they just didn't sleep well last night. As if there's some universal knowledge that bad sleep the night before equals bad mood and emotional reactivity the next day. And it doesn't stop in infancy or childhood or adolescence. It's true when we are adults as well.

And we've seen this data. What I think is concerning is that that neurological signature that we discovered in that study is not dissimilar to numerous psychiatric conditions. And in fact, we're now finding significant links between sleep disruption and depression, anxiety, including PTSD, anxiety, including PTSD, schizophrenia, and most recently and tragically, suicide as well. In fact, short sleep duration is usually predictive of either suicidal ideation, suicidal thoughts, suicide attempts, and tragically, suicide completion. So I think the scope through which sleep is impacting mental health disease, I think, is considerable.

We used to think in psychiatry that the psychiatric disease was perhaps causing the sleep disruption. I think now we've been forced to change our minds. It's not as though it's completely in the opposite direction. It's not that every psychiatric condition is a sleep disorder. That's not true either. But is it a two-way street? I think that that's probably more tenable. In fact, is the dominant flow of traffic perhaps more in one direction than the other? I think that's also reasonable to assume on the basis of the data right now as well. So I think there's clearly an intimate relationship between our mental health and our

sleep health. Matthew, the implications of what you just said, I think, are so profound. We've got to accept in the 21st century, not only do we not prioritise sleep enough, we're a chronically sleep deprived society. We're now going through a mental health epidemic. You know, Mind, the charity here in the UK, say that about one in four people in the UK now in any given year are going to be diagnosed with a mental health problem. That's incredible. And when you hear about that research, we think,

chronically sleep-deprived society, mental health problems otherwise, yes, there are other factors. Okay? I don't think you or... Both of us agree on that, yeah. We're not trying to say it's all to do with sleep but what we are trying to say is that sleep is a critical part of the equation and one that we can no longer afford to ignore um so i find that research fascinating you know and it makes me think as a doctor you know you've mentioned already

type 2 diabetes heart disease mental health problems such as a doctor, you know, you've mentioned already type 2 diabetes, heart disease, mental health problems such as depression and anxiety. You know, I know at our previous discussion, again, guys, I'd point you to that Facebook discussion. We won't have time to go into this today, but we will when I get you back on the podcast. On our Facebook discussion, we did go into Alzheimer's and how, you know, sleep deprivation you feel may be causative now or one of the causative factors that causes Alzheimer's disease. I'm thinking, well, I often say this when I'm teaching doctors, why are we not bringing up sleep quality with pretty much every single patient that walks in through our door? And you could imagine the cost savings to,

you know, our economy. In fact, the Rand Corporation recently did a survey, the enormous cost of sleep deprivation throughout a number of developed nations. What they found was that a lack of sleep costs most nations about 2% of their GDP. So here in the United Kingdom, that's 30 billion pounds of lost economic value caused by insufficient sleep. In the United States, it was $411 billion. In Japan, it was $138 billion. In other words, if you solve the sleep loss epidemic, imagine you could almost double the budget for education, or you could perhaps even half the healthcare deficit, Theresa May just this week, as we're speaking here, the Prime Minister of the United Kingdom,

described a £20 billion injection of funds into the national healthcare system. And there's uproar about where that money is going to come from. Well, you know, if we just simply prioritised and solved the sleep epidemic, the sleep loss epidemic, we could cover that and still have £10 billion left over.

Yeah, I know. And this podcast doesn't sound to be too political, but I would say that I find a lot of the messaging around the NHS in public very short-sighted. It's about pumping more money in to fix downstream issues, whereas we've got to look at prioritising sleep as a society, whether it's the lighting that's used in hospitals when patients are trying to recover from illness, which isn't very helpful a lot of the time. Whether it's teaching our children about it and encouraging good habits at school, but also as parents with our kids, really ingraining.

And I think we've not really got into technology today and how the overuse of technology can potentially be problematic for sleep. I agree, sleep, it's such a simple lever to turn. It's also, well, we'll come into tips in just a second, but, you know, so many health inequalities are there from people from different socioeconomic groups. We know in the UK that you can have as much of a 10-year difference in your life expectancy depending on where you live. One thing I like about a focus on sleep, and I appreciate that there are many pressures in deprived communities, financial stresses, maybe a lot of shift work,

maybe working multiple jobs. So I absolutely understand and recognise that there are significant issues that we have to overcome. But a lot of the recommendations that we're now going to talk about, that I cover in my book, and you cover in detail in your book, most of the recommendations to help people to, you know, get more quality sleep are free of charge. Yeah. You know, I often say that I think sleep is perhaps the most democratically freely available healthcare system for everyone around the world. Now that's a bit of a glib statement on the basis of exactly what you just said, I think about, and the data is quite frightening. We've been looking at this too,

at sort of low socioeconomic status communities. And there, what you'd see is just what you described, you know, higher general social stress that impairs sleep, usually working multiple different jobs, split shifts, working the night work. Often people in those communities are working in the service industry. That usually means that you're either up very early or you're staying in work very late, all of which comprise, you know, factors that work against sleep. So I want to be really appreciative of that. But still, I think, you know, the tips that we can do right now to start sleeping better every night should be applicable and for the most part utilized by just about everyone, as long as you don't have a sleep disorder. Well, Matthew, normally I end the podcast off by asking people for four key tips

that people can put into practice immediately, but we don't have to limit it to four. I want this podcast to inspire people to not only take sleep seriously, but to give them some practical help. So immediately after listening to this, I can put the headphones down and go, right, I'm going to do what Professor Walker's headphones down and go right I'm gonna do what Professor Walker's asked me to do I'm going to try you know these five things today in your experience and you've been interviewed all around the world now to do with your book what what are those common things that people aren't doing that they could do to help improve their sleep

yeah so there's probably um maybe five things um that people can do right now to get better sleep. The first is regularity. Going to bed at the same time and waking up at the same time, no matter what, even if you've had a bad night of sleep, still try to wake up at the same time. Just understand it's going to be a tough next day. And then get to bed at the same time that following night and you'll have a good night of sleep. You'll sort of sleep a little bit more soundly that night. Even if it's the weekday or the weekend, don't do what we call social jet lag, which is sort of where you sort of sleep too late

at the weekend and then on Sunday night, you've got to drag your body clock all the way back and try and force it to sleep at a time when you haven't been sleeping before. That's torture. Regularity is key. The second thing is temperature. We've spoken a little bit about that, but keep your bedroom cool and probably around about 18

degrees Celsius, which is colder than most people think. But cooling the room down takes your body into that right sort of thermal space for good sleep. It cools it down. Darkness we've spoken about too, but we are, I think, a dark deprived society in this modern era. And you need darkness at night to allow the release of a hormone called melatonin, which helps time the healthy onset of your sleep. So yes, it's to do with blue light sort of emitting devices, screens, phones. Those are things that you should try and stay away from in the last hour before bed. But it's not just that. It's also overhead lighting. You know, we don't need to be bathed in electric light all night. In the last hour before bed, just try

turning half of the lights off in your flat or in your home. You'd be surprised at how soporific and sleepy you become when you're shrouded in darkness. So that's the third thing. The fourth thing is, I would say, walk it out. And what I mean by that is don't stay in bed if you've been awake for 20 or 25 minutes, either trying to fall asleep or you've woken up and you're trying to get back to sleep. The reason is because your brain is this wonderfully associative device and it will start to very quickly learn that being in bed is about being awake rather than asleep. So what you need to do is after about 25 minutes, just relax, understand that sleep is not quite here yet. Go to a different room in dim light,

read a book or listen to a podcast, but don't check email, don't eat because it trains your brain to expect that in the middle of the night. Only return to bed when you are very sleepy. And that way your brain will start to relearn the association that your bedroom is the place of sleep rather than the place of sleep. I think that's a really important tip, Matthew, that, you know, I know even from our first conversation on Facebook, but, you know, whenever I talk about sleep, people can often get really wound up about this and say, you know, I'm doing all those things, I can't sleep. And they've really just, without trying to, their brain has just got into this position where it's been trained not to sleep. It's been trained to not associate the bedroom with sleep.

So many people I see, you know, when I hear about on social media are doing work emails right up to the moment they fall asleep. And, you know, we mentioned children before and I often say, you know, children need a bedtime routine. We know that. Why as adults do we think we're any different? We should. And you're absolutely right. You know, we've turned the bed in this day and age often, you know, into a kitchen. We've turned it into an office. We've turned it into a cinema. You know, we do all of these things typically on the bed, which then it does impact the brain's association. It gets quite confused about what this thing called the bed is all about. So I think that that's a very helpful tip. And try not to get too anxious if you're sort of

falling asleep. I know that probably a lot of what I've been telling people will make you feel anxious if you're not being able to get the sleep that you need. But try not to worry about it. Everyone has a bad night of sleep. Just get up, understand that you're going to be awake for a little bit longer, and then go back to bed and you will start to relearn that association. And in fact, a lot of, you know, people and patients will say to me, well, you know, I've been falling asleep on the settee watching television and then I get into bed and I'm wide awake and I don't know why. And again, it's because of this association that you've learned with the bed. The final two things, one of which we've mentioned, is what you intake into your body, caffeine and alcohol. We've spoken about caffeine, but I'll speak about alcohol quickly.

Many people use alcohol as a sleep aid, and it is anything but an assistant to sleep. Alcohol is a class of drugs that we call the sedatives, and sedation is not sleep, unfortunately. Sedation is not sleep. I love it. It's very different. So what you're doing when you have a nightcap or you use alcohol to try and get to sleep, and many people do understandably so, they mistake one for the other.

You're just knocking your cortex out. You're not in natural sleep. The two other problems with alcohol and sleep, firstly, alcohol will fragment your sleep. So if I were to record someone's sleep in the laboratory after they've had a couple of drinks, their sleep is littered with all of these awakenings throughout the night.

Now, you tend not to remember waking up, but the next day you feel, again, unrefreshed. You don't feel sort of bright and alert or restored by your sleep, but you don't remember waking up, so you don't link it to the alcohol. But alcohol is bad at fragmenting your sleep, produces poor quality. The final thing alcohol is good at doing is blocking your dream sleep or your REM sleep.

And we know, to come back to our conversation, REM sleep is critical for emotional first aid. REM sleep provides overnight therapy. It's a form of emotional convalescence and alcohol will block that REM sleep quite viciously so those would be the five tips I think for better sleep yeah Matthew thanks I love that um just just to say on alcohol is it dose dependent so for example you know some people say well I'm okay with one glass of wine but two or three glasses is going to fragment my sleep. You know, can you comment on the dosage there?

Or would you advise people who are struggling with sleep to knock it on its head, basically? I know, and it's so hard for me to answer this. And this is one of the many reasons why I'm such a deeply unpopular person. I don't think that's fair to say. But, you know, firstly, I don't want to sound puritanical. You know, life is to be lived to a degree. And all of these things that we're discussing, we're trying to speak about the extremes. But I also want to empower people with the knowledge.

I'm not here to tell you necessarily what you should or you shouldn't do. I just want to give you the scientific facts and then you can make the choice. I would say, unfortunately, that even just one glass of alcohol in the evening, we can see that, we can measure that. You can measure that. In your lab, you can see that you're not getting the same deep level of restorative sleep even with one drink.

Even with one drink. So I know it's hard, but now everyone should have a social life and sort of enjoy a drink now and again. I think the best advice would be this. if you're going to bed feeling tipsy you probably have had too much alcohol in terms of sleep impairment well i i think you know i i so resonate with it with so much of what you've just said which is you know this podcast what i do what you do it's not about telling people what to do you know i've got no interest of telling someone what they should

do i have no right to tell someone what they should do with their lives what i think we're trying to do is to educate people inspire them empower them to understand what lifestyle choices they're making and how that could impact their health and i i always draw the analogy with going out how many few drinks with your mates on a Friday night? People know intuitively that if I go out for a drink on a Friday night and have three or four pints, let's say, you know what, my Saturday morning might be a bit of a write-off. I may not be functioning as well as I might want to. But you're going into that with that knowledge.

You're saying, you know, I know the effect alcohol has on me, to that with that knowledge you're saying you know i know the effects alcohol has on me but i'm going to get so much enjoyment out of my night out tonight that i'm willing to put up with the consequences what i think we're both trying to say is guys we just want to empower you we want to help you understand the impact that caffeine might be having on your sleep that alcohol might be having on your sleep that the fact that you're on your work emails before you go to bed might be having on your sleep do with that information what you will, you know. That's how I would put it. I so agree because I think, you know, a lot of what you speak about in your book,

which is far more wide-ranging than mine, because I just take one of the things, you go after four of the key pillars, which is so much more impressive. I think it says so much about the difference between me and you, Rangan. Well, I'm a clinician, right? There's a big difference, right? There is, but I still think it's a heroic thing. But what I would say, I think, is that, yes, a lot of people are aware of some of these things.

You know, like it's good to be physically active. You know, I should try and stay away from drinking too much alcohol. But I also think that there's a lot of what we discuss, you know, I hope in both books, that is perhaps knowledge that people aren't aware of. And if only that they were aware of it, they would actually want to do something different. That's the sort of the case that I'm really passionate about is that people, as long as you know the information and you choose to do otherwise, no problem at all. A lot of people just are either misinformed or entirely, when it comes to sleep, uninformed. That's the goal. That is the goal. And it's really about, it's that empowerment piece. And

this is one thing I just want to end on is just to say, guys, look, it may not be that you can just change one thing and suddenly have a great night's sleep. You might have to change three or four things together you know that's certainly my experience it's like you know Matthew you know you're a researcher so a lot you know you'll do research and showing what caffeine does on showing what alcohol does and but I would say as a clinician use that research but maybe you might have to try a few things like you might try for example one week with no caffeine and no alcohol and see how you sleep because then you can be empowered to just to decide what are you going to do after that are

you going to go back or maybe then i always try and get people sleeping as well as they've ever slept then they can start reintroducing some of these lifestyle things that they want and they can say oh wow that's interesting i i felt great last week, but now when I have a 2pm coffee, you know what? I'm not quite as good. Okay. That's going to teach me now that I'm going to knock it a bit earlier in the day because I think ultimately nobody's going to follow your advice or my advice simply because we told them to. I think it's only when they start to feel the difference themselves, they go, wow, you know, I kind of like feeling good. Yeah. And I think, you know, I love your point about just trying to give it time to, you know, sleep and starting to change your sleep and seeing the effects of getting better sleep. It's a little bit like exercise at the gym. You know, you're

not going to go to the gym one day and wake up looking like Arnold Schwarzenegger. You know, it just takes some time. But if you commit to it, you will see gradual change. And it's the same thing with sleep as well. But I also think I love the idea of you putting sleep in that bedrock place and then starting to introduce the other factors. What's lovely is that many of them will actually fall in place when sleep is stabilized. And I'll give you a good example of diet. We know that without sufficient sleep, two critical appetite hormones go in opposite bad directions. One of those hormones is called leptin, which is a hormone that sort of signals to your body you're full,

you don't want to eat anymore. The other hormone is called ghrelin, which does the opposite. It says you're not satisfied with your food, you want to eat more. And despite leptin called ghrelin which does the opposite it says you're not satisfied with your food you want to eat more and despite leptin and ghrelin sounding like two hobbits they are actually real hormones what's interesting is that when you sleep deprive people or even just limit them to maybe just like five or six hours of sleep for a week levels of leptin which say you're full don't eat more they drop down levels of ghrelin that ramp up your hunger and say, I've just eaten a big meal, but I'm not satisfied. I want to eat more. That hormone skyrockets when you're underslept.

So no wonder people who are sleeping just five to six hours a night will actually eat on average somewhere between two to 300 extra calories every single day. Yeah. So you can solve sleep and you will actually start to not want to eat as much. Yeah. And this is why a part of weight loss is to sleep better. It's a critical factor. And I think next time I get you on, Matthew, we'll probably go into detail on that. We'll probably go into detail on Alzheimer's and maybe even things like menopause

or symptoms and hormonal symptoms that I also see sleep deprivation playing a huge role in. I know you're on a really busy schedule. That's how it is when you have such a popular international bestselling book. And you know all about that too. Well, guys, I'd highly encourage you to pick up Matthew's book, Why We Sleep. It's absolutely brilliant. It's got pretty much everything you've ever wanted to know about sleep. I think you'll probably find in that book. I look forward to when you release a later edition, when you've got newer research coming out in the future at some points. But Matthew,

one question I like to ask my guests who are leading researchers in the field is, as you became more and more aware of all this sleep research, what was the biggest thing in your own lifestyle that you changed on the back of your research? I think it was probably caffeine. I think just seeing the data and then doing those types of studies ourselves, and particularly the finding that we discussed were, even if you're asleep, the quality of that sleep is just not as deep. That really got me concerned. And that's when I really started to pay attention to my caffeine content. And are you teeter-to-nower caffeine or are you? So right now, yeah, I am. I drink decaffeinated tea and I drink decaffeinated coffee.

I sometimes, you know, I've ebbed and flowed between sort of having coffee in the morning, because I do feel it's alerting benefits. But, you know, we didn't necessarily evolve to be medicated with caffeine. And I think anyone who's, you know, drinking caffeine at 11 a.m., which on the basis of your circadian rhythm, if you listen to the wonderful podcast with Sachin Panda that you did, you know, your peak of your circadian rhythm is right around sort of the 11 o'clock period. That's when it should be almost impossible for you to fall asleep. But yet, you know, I sometimes look around on an airplane when I'm leaving and people, half the plane is asleep at 11 o'clock. And if you're self-medicating your sleep deprivation at 11 a.m. with caffeine, it usually means that you're perhaps just not getting enough sleep. And

that's probably been one of the greatest, I think, influential factors. That and the impact on my productivity, I think that was the most underrated. And it actually forced me to start doing a lot of research on sleep loss and productivity that maybe on a second podcast, we can talk about. But my ability to maintain focus and produce high quality output work is dramatically dependent on the sleep that I've been having at night. That absolutely echoes what Professor Panda said a few weeks ago on this podcast. When he goes off caffeine, his productivity goes up. So, guys, look, no one's asking you guys to cut out caffeine. You know, I know how much you guys love it.

I have certainly had my own love-hate relationship, well, more love of a relationship with coffee in the past, but I have dramatically reduced it and I'm feeling better than I've ever felt. Matthew, I really want to thank you for the time you've made today to come onto the show, to really talk to my listeners who really are big fans of your work,

really are looking for those actual bits of information that they can take into their lives. So I want to thank you for that. I absolutely will take you up on your promise. I'm going to call it a promise to come back on the podcast. It is a promise. Guys, look, that is the end of my conversation

with Professor Matthew Walker. Don't forget, you can see all the show notes at drchatty.com forward slash why we sleep, everything we've talked about, a lot more articles from Matthew. I'm going to put them all there so you can continue your learning experience. Guys, I'd love you to take a screenshot of the podcast, share it on social media. We want to get this information on sleep to as many people as possible. And you can help us do that by promoting and sharing this podcast on social media. If you

could tag me, but you could also tag Matthew. Matthew, what social media network do you tend to be on? Yeah, so I'm on the internet all over the place on Sleep Diplomat. So at Sleep Diplomat on Twitter, and you can find me on the web at sleepdiplomat.com. And I would love to learn more about what people enjoyed and just hear their thoughts about sleep on Twitter. That would be wonderful. Yeah, guys, so please do tag me, tag Matthew. I want to put all those social media links on the show notes.

Do check them out as well as sharing this with your friends. If you could go on to whichever podcast platform you are listening to this on and give the podcast a five star review. What it does is it helps raise the profile of the podcast it helps get the podcast to more people but it also helps me attract fantastic guests such as professor walker so i can get you more world-class world-leading information coming in the future guys i hope you've enjoyed today's podcast from matthew and myself thank you take care and sleep well, everyone. That concludes today's episode of the Feel Better Live More podcast. My hope and Matthew's hope is that after listening to these two conversations, you start to shift your attitude towards sleep. I've said many times before that if you are not prioritizing sleep in the 21st century,

you are probably not getting enough. Use the tips that we went through in this podcast to make small changes that will improve your sleep health immediately. There are plenty more tips on sleep in Matthew's book, but also in my book, The Four Pillar Plan, which is available in many countries around the world. And in the USA and Canada, it's available under a different title, How to Make Disease Disappear. Matthew and I have touched on the fact that sleep is a significant stressor on the body. And I go into detail about this, as well as stress in general, in my upcoming book, The Stress Solution, The Four Steps to Reset Your Body, Mind, Relationships and Purpose, which is available to pre-order now. If any of these books interest you, if you go to the show

notes page, drchatterjee.com forward slash whywesleep, you can access everything that Matthew and I discussed. You can look at many different articles that Matthew has written, but you can also order some of these books. If you prefer video, the entire video of my conversation with Matthew is now available on my YouTube page, which you can find at drchastity.com forward slash YouTube. Guys, as I mentioned in the introduction, this is the very final episode in season one of my Feel Better Live More podcast. I'm super grateful for the support and the love that you have given this podcast since I launched it back in January.

We have together almost hit 1 million listens now in just six months, which is frankly phenomenal. Remember, if you have two minutes to fill out a really short survey at drchatterjee.com forward slash survey it will help me understand what you want to see more of and what kind of guests and information you would like me to have on the show i will be back with brand new episodes every single week from the first week in september so make sure you have pressed subscribe so that you can be notified when the next episode of Feel Better Live More comes out. From me now, I'm signing out from season one of the Feel Better Live More podcast. I hope you have a wonderful summer. Enjoy whatever you are doing. Remember, relaxation is a critical pillar of health. So I hope you all manage to get some time to chill out over August.

I will see you back after the summer. And remember, it is always worth making small changes to your lifestyle because when we feel better, we live more. Thank you.