Feel Better, Live More with Dr Rangan Chatterjee - The Science of Sunlight: How 20 Minutes a Day Could Transform Your Mood, Energy, Sleep & Longevity with Dr Roger Seheult #586

Episode Date: October 14, 2025

When we think of sunlight, vitamin D is usually the first thing that comes to mind. But the truth is, the full spectrum of light that we get exposed to when we spend time outside plays a vital role in how we sleep, how we feel and even how our cells create energy.   This week’s returning guest is Dr Roger Seheult, who believes that sunlight is one of the most accessible and underutilised tools we have for improving health – and the science he shares is compelling.   I’m delighted to welcome back to my Feel Better, Live More podcast for our third conversation.  Roger is a quadruple board-certified physician in Internal Medicine, Pulmonary Diseases, Critical Care and Sleep Medicine. He is also an Associate Clinical Professor at the University of California, Riverside, and Assistant Clinical Professor at Loma Linda University.   Alongside his clinical practice, he co-founded MedCram, a medical education platform with over one million YouTube subscribers, widely used by hospitals and medical schools worldwide. Roger is also a sought after lecturer and has received multiple awards for his contributions to medicine and education. His passion lies in making complex medical science accessible, and he regularly lectures to schools, hospitals and media outlets.   In this conversation, we discuss: Why deficiency in sunlight can show up as fatigue, poor sleep, inflammation or even raised cholesterol. The three “macronutrients” of light – visible, ultraviolet and infrared – and how each plays a different role in mood, immunity and cellular energy. How infrared light penetrates deep into the body, supporting mitochondrial function and how it may help protect against diseases such as diabetes and dementia. Why spending 15–20 minutes a day outside – even in the shade – can be enough to recharge our cells. The growing evidence that sunlight exposure lowers the risk of all-cause mortality, cancer and heart disease. Practical strategies for getting the benefits of sunlight safely, even if you live in colder climates or spend much of your day indoors.   Roger also shares his “eight laws of health” – simple, timeless principles that include nutrition, rest, fresh air and sunlight – and explains how neglecting them leads to the chronic conditions he often sees in his work in intensive care.   This is a fascinating conversation that will change how you think about sunlight. It isn’t just something that makes us feel good – it’s a fundamental part of how our bodies stay healthy. And the best part? It’s free and available to us all.   I hope you enjoy listening.   Support the podcast and enjoy Ad-Free episodes. Try FREE for 7 days on Apple Podcasts https://apple.co/feelbetterlivemore. For other podcast platforms go to https://fblm.supercast.com.   Thanks to our sponsors: https://www.boncharge.com/livemore https://www.calm.com/livemore https://thriva.co/   Show notes https://drchatterjee.com/586   DISCLAIMER: The content in the podcast and on this webpage is not intended to be a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your doctor or qualified healthcare provider. Never disregard professional medical advice or delay in seeking it because of something you have heard on the podcast or on my website.

If I were to say, what is the single biggest intervention that someone can do right away that would show not only benefits in the short run, but also in the long run, and is the lowest hanging fruit, there's no question in my mind that sunlight is that intervention. Hey guys, how you doing? I hope you having a good week so far. My name is Dr. Rongan Chatterjee, and this is my podcast, Feel Better, Live More. When you think about improving your health, do you think about how much time you're spending outside? You see, I think many of us have come to the conclusion that spending time outside in the sun is only about our vitamin D levels, but honestly, it is so much more than just that.

Our exposure to natural light plays a vital role in how we sleep, how we feel, and even how ourselves creates energy. This week's returning guest is Dr. Roger Schwell. Roger is a quadruple board-certified physician in internal medicine, pulmonary diseases, critical care and sleep medicine. He's a professor at the University of California and at Loma Linda University and is also the founder of MedCram, a medical education platform, with over 1 million YouTube subscribers

widely used by hospitals and medical schools around the world. And I think for me, one of the things I love the most about Roger is that he is someone who, like myself, has a deep passion for making complex medical science accessible and easy to understand. In our conversation, we discuss the eight laws of health and how neglecting them leads to the chronic conditions that Roger ends up seeing in his patients. Why a deficiency in sunlight and time outdoors

can show up as fatigue, poor sleep, inflammation, and even elevated cholesterol levels. The three macronutrients of natural light, visible, ultraviolet and infrared, and how each one plays a different role in mood, immunity, and cellular energy. Why spending 15 to 20 minutes a day outside even in the shade can be enough to recharge ourselves, the growing evidence that sunlight

exposure lowers the risk of all-cause mortality, cancer and heart disease. And of course, we also cover practical strategies for getting the benefits of sunlight, even if you live in colder climates, or spend much of your day indoors. I think this conversation has the potential to fundamentally change the way you think about natural light. Spending time outdoors is not just something that makes us feel good. It is an essential ingredient that our bodies need to stay healthy and thrive. And the best part is completely free and available to us all. Dr. Schwartz, you are really passionate about the importance of sunlight for multiple aspects of our health. So right at the top, I wonder if we

could start with the common signs that might indicate someone has a deficiency of sunlight in their life. It could be a whole host of things. When you look at the studies of lack of sunlight or the studies where people get enough sunlight, we're literally talking about mortality. And we can get into this later, but if you look at the particular causes of death as you go into the winter season, it's infectious diseases, it's non-infectious diseases. So it's going to be interesting to sort of pin down exactly what symptoms they would be. But if we have to do that, I would say things like fatigue, inflammation, pain, inability to sleep. I mean, these are very broad symptoms, but symptoms nonetheless, I mean, there's also laboratory findings. For instance,

elevated cholesterol, elevated triglycerides. These are things that have actually been statistically shown to improve when there is more sunlight in the forecast or in the weather report for those periods of days where those subjects are actually tested. There was an Oxford study that actually looked at that that we can get into. So it's really, look, if I were to say, what is the single biggest intervention that someone can do right away that would show not only benefits in the short run but also in the long run and is the lowest hanging fruit. There's no question in my mind that sunlight is

that intervention. That is such a bold statement in many ways. It's a statement that many people have probably not heard of before through the lens of health. Because when we think about health, we're thinking about nutrition, exercise, sleep. And of course, these things are important. But I guess the thing about sunlight and I guess broadly speaking natural light is that we've not really prioritized it or spoken enough about it for quite a while now, have we? That is true. And if we look back historically, this was not something that we ignored. historically in terms of health. If we just go back 100, 120 years,

and I always like to reminisce on this, a building in the United States, that's 100 years old, it could be a historical monument. In the UK, not so much. I mean, you have buildings there going back hundreds of years, more than hundreds of years, and you can see hospitals, buildings that were designed to heal,

and you can see very clearly that they were designed when they're over 100 years old, to bring light in, to bring fresh air, in. And look, I'm not telling you something that you don't already know. Florence Nightingale, who by many have been considered to be the founder of modern nursing, said when she was taking care of English soldiers in Crimea, said, look, there's two things that I see that have the biggest impact on the health of my patients. Number one, fresh air, but a close second to that is light, sunlight, not just daylight, but direct sunlight. And she's quoted as saying that. And she was

no, she was there. She was at the bedside. She was known as the lady with the lamp. And that was well known at the time. And we have sort of forgotten about that. But with the benefits of modern science and technology, we can now actually literally get down to the molecular levels and show how getting out in sunlight can be tremendously beneficial on so many different levels. Yeah, it's interesting. As I was thinking about our conversation today, I was thinking about why is it that we have perhaps undervalued natural light and sunlight over the past few decades? And of course, we can say that there wasn't enough science, and as the scientific studies are done, there's more awareness, so we can put that into practice. And I think,

there's definitely some merit to that. At the same time, I think sometimes it comes down to what we can easily see, right? So we can see the food on our plates. We know what we're putting into our mouth. We can see how many steps we've taken or whether we've gone to the gym or not. So these things are easier to visualize and to track. But I've often thought stress has undervalued in terms of the impact it has on us because a lot of stress is invisible. We can't see it. And you can perhaps make the same case for light. Yeah, of course, the sun we can see. But as we're going to dive into, you know, sunlight is, there's visible things coming from the light. There's invisible things coming from the light. So I wonder if some of this is to do with like literally

the visibility of these components in our life. Absolutely. And that's what I've tried to, and you've tried to bring to people who are watching and who are interested in this, is to make health graspable at any level so that people can understand that. I have to confess, and we'll get into this later, I have just come across a wonderful little device that I love to use, and I can probably share some of these things later. It's a little film, and in the line of what you're talking about, it's a little film that you put over the lens of your smartphone camera. What it does using actually some quantum physics is it'll take infrared light, which has a lower energy, and using rare earth metals and some anti-stokes effects and some physics, it'll actually shift the frequency of that high enough up into the visible spectrum so that you can actually see the type of light that we're going to talk about today, which is primarily infrared light. and you put this over your camera,

and it's like Christmas morning from me, literally. I mean, I'm going out everywhere. I'm shooting things. My kids think I'm crazy. But it's an amazing transformation where you can literally see the light coming off of the leaves. You can see what's going on inside. When you come into your house, how dark it is,

because there's a complete absence of infrared light. You can see how much the windows are preventing that light from coming in when you open one of them and you can see the difference. It's quite stark. And I've been posting actually these things on social media, and you're absolutely right. People are like, wow, I've heard you talk about infrared light, but I had no idea that that's how much light was literally coming off of the trees. And this is how much light is literally being blocked by the windows that are supposed to be letting this light in.

And it's so devoid inside the homes where we spend 93% of our lives. And what you just said is so true about the fact that we can't see. see some of the most beneficial effects of the sun. I follow you on X, Roger, and I've been very much enjoying all these photos that you've been posting, actually, because it does make the invisible visible. And I've been aware, and like you've been writing about this so many, is the importance of light, but I don't think I had that full appreciation of infrared light and actually how important it is.

And literally when you come from outside to inside, it goes down dramatically. So, I mean, we're going to talk about that, but perhaps we should just zoom out a little bit and go, okay. So someone listening is getting so far that, look, light is important, okay? We know that getting outside is important. And many people, maybe as a kid, were told by their parents, get outside and play, okay? but let's really try and unpick what is it about being outside that has all of these different aspects on our health because it's not all infrared light, is it?

There's other components as well. Absolutely. So when we look at the light that's coming from the sun, there's basically three types of light that we want to talk about. There is obviously the visible light, which you can see. And there is countless studies and decades of research that shows that visible light itself has a tremendous health benefit on the individual. Why? Number one, it prevents depression.

So we know that people who live at high latitudes, who are not exposed to enough visible light, especially during the winter months when the days are short, when they're getting up before the sun gets up and they're getting home after the sun goes down, they are susceptible to seasonal affective disorder. And a very easy way of overcoming that particular issue is with visible light into the retina that stimulates a portion of the brain that prevents depression from happening. So that's that's visible light. That's that first aspect. We also know that visible light, especially early in the morning when the sun is coming up, helps to ground and to establish a good circadian rhythm. There's something called the Zeitgeber that affects

the timing of all of the processes in your body. So visible light is important. So those two things right there are just the top of the list in terms of the things that visible light does when you get outside. Now, in terms of the two types of invisible light, when we go past violet, we get ultraviolet light. And we all know that ultraviolet light, specifically ultraviolet light B is very important

in the production of vitamin D, 3, in our skin. So that type of high energy, so this is short wavelength, high energy, when you look at the visible spectrum, you have the colors of the rainbow, when you go off to the violet side, the wavelengths get shorter and the amount of energy in those photons is much higher. They have the energy to penetrate just very shallowly into the skin, which is where they're needed. But the energy that they deliver is enough to actually break the bonds in these molecules of cholesterol. so that it can actually change it and convert cholesterol into vitamin D. So that's, we know all about, well, we know a lot about vitamin D. We've known about it for a long time. And we often, to our detriment, simply chalk up sunlight and sunlight exposure just to giving us vitamin D. Now, surely it gives us vitamin D.

And vitamin D is very important. There's a number of trials that show that vitamin D is important. And I supplement as well. And I think it's a good idea to supplement. if you're low. Vitamin D is important, but that's just one aspect of invisible light. Okay, so we've talked about visible light. We've talked about ultraviolet light.

Let's go to the other extreme. So past red, this is also invisible, but this is very long wavelength, and this is what we call infrared. And today we're going to talk about red and infrared lights, and there's a couple of aspects of this light that's very important to understand, and that is, is that as opposed to short wavelength, which has high energy, infrared light is a lower energy type of light with a long wavelength. But here's the key, and this is the point that people sometimes mix up.

It's this long wavelength that's actually able, despite the fact that it's low energy, is able to penetrate deeply into the human body. And because of that, this is really important to understand. Going outside into the sun on a sunny day is not, just for the skin. It's not just for the eyes. It's for the entire body because this particular type of light from the sun, which is long wavelength, has actually recently been shown. There's a paper by Glenn Jeffrey from University College London, professor of ophthalmology. He's just

published in nature scientific reports that this type of light from the sun not only penetrates deeply into the human body, but he has actually been able to detect it on the other side of a human being. In other words, it goes right through. Yeah, it's amazing. As you were describing that, Roger, I was thinking, okay, we understand when we think about food that there are three macronutrients, right? Fat, protein, and carbs. Yeah. So perhaps now we need to start thinking about light in the same terms. We're now saying, okay, there's light. but under lights, there's at least three different components from what I'm understanding from you, okay? The first one is that visible light. So we can see that. That's why going out first thing in the morning is so good for our circadian rhythm. It helps set the kind of clock in all of our cells, and that can have an impact therefore on things like mood, sleep, and our guts.

There's also a second type, which is the ultraviolet light, the UV light. And of course, for many years, we've heard about vitamin D and how important that is. And many people know that sunlight outside on your skin at certain times of year will increase your production of vitamin D. So that second component is the UV light that's going to help with vitamin D, which of course has a very powerful effect on our immune system and many other things. And then there's this third component of lights, which we're going to spend a lot of time talking about today,

which is infrared lights. We cannot see this part of the light spectrum. But as you're going to describe, it has a powerful effect on our mitochondria. And that's why, if we sort of circle back to the start of this conversation, you said that going outside and getting sunlight is the most important thing that we can all do to improve our health, right? Which I'd love. Because when we understand that the mitochondria

sits at the heart of everything and you're going to, you know, I've seen many of your Medcrown videos where you've actually described the powerful effect that infrared light has on our mitochondria, you're like, well, of course. A lack of sunlight

is potentially going to be impacting energy, vision, heart disease, stroke, dementia, everything. So I know I said a lot there, but would you agree that it's helpful to think of this like the macronutrients of food? These are also the macronutrients of light, perhaps. You know, I actually hadn't thought of it that way until you just mentioned it, but you're absolutely right. Food is a general category, as is light, but there's different aspects that that food provides in our body depending on our needs. And just like proteins are important for

muscle and fats are important for myelin and the brain and carbohydrates are also important in terms of energy that is necessarily immediately. So too is vitamin D needed for certain aspects and the products of infrared radiation is also important. So I think it's actually a very good analogy and it makes us think about things holistically. And that's really, I think, going to be the underlying theme that we're going to see today is what we tend to do in science, I call it scientific reductionism, and other people have called that too, is where we find something that's beneficial. We try to isolate the active ingredient. We amplify it and we put it into a pill and we patent it and we give it to people. And I guess what I'm saying here is that when you go

outside, you're getting a whole buffet, a whole cornucopia of things that are mixed together dynamically for your body at the right time. So think about this. It's amazing situation. There is a clock in your body that is set by the sun. And as the day goes forward, the amount of ultraviolet light and infrared light that you're getting from the sun also changes along with that circadian rhythm. Is it possible that we were, that we are connected to that circadian rhythm so that we're supposed to be getting lots of infrared light in the morning and lots of infrared light in the evening when that's abundant? And we are ready to take in ultraviolet light in at noontime. I'm speaking out loud. I'm thinking out loud, but I think what people will

see as we go through these studies and we get into the minutia of some of this and the details and the trials and the evidence is you'll start to see that really the best solution is not to go out and necessarily buy a lamp or a red light thing. I mean, those have their place. But if you have the ability and you can do this, it's to go outside into the sunlight because everything that you need is literally right there. We're saying sunlight a lot. And of course, you know, any time it's day, wherever you are in the world, yes, the sun is there, causing that, you know, illuminating the planet for us. But of course, sometimes we can see the sun directly and other times it's hidden behind cloud.

When it comes to these three macronutrients of light, as it were, is there a problem? Or how do we address, you know, receiving these nutrients if we live, let's say, in northern England? where it's not sunny all the time and often it is cloudy. Yeah, that poses a problem. So let's get into the physics of infrared light and talk a lot about what it is and what it does and why it's important. And then it'll become clear about where we are with clouds and other things as well. So as we talked about, infrared light recently published article in Nature Scientific Reports, Glenn Jeffrey, took these people outside, and it was high noon, and there was no clouds in the sky,

and he was able to show that infrared light literally goes through the body, can be detected out the other side, and the wavelengths in that paper that he found that were the best at doing this was in the infrared spectrum, no surprise. And specifically, he picked 850 nanometers, which is a wavelength that's in the near infrared spectrum, but definitely cannot be seen by the human eye. So there's a couple of properties that you need to understand about infrared light in nature. Number one, as I said, it penetrates very well. Number two, it's well absorbed by water molecules.

So there will be a diminution, a reduction in the amount of infrared light on a sunny day if there is cloud cover. That's going to diminish it somewhat. The other thing that's actually very interesting as well is that leaves on trees and grass are highly reflective of infrared light. You may have realized this independently. If you go out on a nice summer day, sunny day, and you touch leaves that have been the sun for hours, they're not hot because they're reflecting the particular type of light that gives warmth from the sun. And you also know this when you go out on a sunny day. If you close your eyes, cover your eyes, someone spins you around, you can actually feel what side of the body

is facing the sun. And the reason is because infrared light not only penetrates through your body, as we've just discussed, it can also very easily penetrate through your clothes.

And so you can feel that. That warmth that you feel from the sun is infrared radiation, penetrating deeply into your skin, going through the tissues, and activating the heat receptors as they go through.

So what I've done actually is, In terms of your question about clouds, I've taken that infrared film, put it onto my iPhone. I've actually posted this on the internet. And I've done the very same time of day as there was clouds going overhead. And I took a photograph and a video of when it was full sun and when there was minimal sunlight because it was covered by clouds. And what you can see very clearly is that the amount of infrared light doesn't diminish that much

because the leaves and the trees are so reflective of that, that infrared light is sort of spreading everywhere, and you can pick that up very easily on the film. I'll be happy to share those with you. What is the relevance of this idea that in the Glenn-Jeffrey study whereby, you know, the sun is coming on to us, but some of that light is going through us, what does that tell us?

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And it basically went right through. And they were able to measure a fraction of that light out the other side. And what the authors of that paper said was that clearly infrared light is able to penetrate into the body, be absorbed, but it's still able to penetrate through 30 centimeters. Now, the question is, what is it doing in the human body? What is it up to? What affects does this actually have? So I try to take this slowly with people because the first thing that people have difficulty understanding is that sunlight actually is affecting their entire body when they go outside, not just the skin. Once they understand that, the next question is, okay, well, what

is this infrared light actually doing? For that, we actually have multiple studies that have looked at this. And all of them have been, well, many of them have been on a petri dish or in a laboratory using infrared light from artificial sources, showing very amazing changes. And none of the scientists really understood at the time that this could be the effect from the sun because they had no idea that infrared light was able to penetrate that deeply. So if, you look at the literature in the last 10, 20 years, you'll see people doing tests with low-level laser therapy and things to see, you know, how deep this is going. And the way they were doing the experiments was looking to see how much it penetrates in a straight line. And they were getting,

you know, maybe a centimeter, maybe a few centimeters. Just back in 2019, Scott Zimmerman published a paper in melatonin research that he predicted it would be about eight centimeters based on his research, we now know it goes much more deeply. And there are basically all of the cells of the human body, even through bone, infrared light can penetrate through. So think about the effects on the brain. The question, again, and you alluded to this, is what is this infrared light actually doing in the human body?

Well, we know it's actually affecting changes in the mitochondria. And this is the organelle of the cell that is responsible for producing energy. It's the batteries of the cell. Now, this is important for the obvious reason, but for another reason, too, which is that we have seen scientifically with research that as we get older, as we age 40 years, for instance, we can see a drop in the output of these mitochondria in our cells by as much as 70% in the retina, but over the entire human body, 30 to 50% in some cases. So there's a material drop in energy production. And what infrared light is doing is it is restoring in some way, in a partial way, the energy output and the efficiency of those mitochondria to restore energy to the cells, whatever they happen to be cells of, whatever organ they happen to be. And they're restoring the function of those cells.

And this paper that Glenn Jeffrey showed, in this case, he was checking. for color vision, which is highly dependent on energy output. And it showed that in the retina, the mitochondria was able to effectively go up enough that the threshold for color blindness in these subjects drops statistically significantly enough to show an improvement in their vision just with this type of light exposure. Yeah, it's certainly incredible. As you're describing that, Roger, I'm sort of thinking about a battery that we charge, right? So, or a phone, right?

We kind of understand the concept that our smartphone needs charging, right? So many of us in the evening, you know, during the night, we'll charge our phones. So in the morning, they're ready to do what we need them to do throughout the day. But if we think about light and the fact that we're living these indoor lives now, and yes, you mentioned scientific reductionism, of course, that absolutely plays into vitamin D where for many years, you know, we've just thought sunlight equals vitamin D. It's like, no, wait a minute. Sunlight equals many things.

One thing is vitamin D, but there's many other things that sunlight does on our body as well. But maybe this infrared light is almost charging us. So our cells and our mitochondria are actually getting charged up. And if we live indoors and we're hardly exposing ourselves to natural light, maybe many of us are running around on low charge. all the time. You know, it seems like quite reasonable based upon the research

and based on what you're saying, to think that actually we're almost being suboptimal versions of ourselves by not getting out in the natural light and getting charged up. That's a great analogy. You know, have you ever put your phone on low battery mode

because you didn't have enough charge and you couldn't get to a charger fast enough? Yeah. It's jittery, right? I mean, it doesn't work as fast. This is, I believe, a very good analogy as to how we are functioning. When our mitochondria go down, our metabolism goes down. We gain weight, depending on the cell type that we're talking about.

If it's in the brain, it's dementia. If it's in the heart, it's congestive heart failure. If it's in the pancreas, if it's in our peripheral tissues, it's insulin resistance. All of these things have been tied to mitochondrial dysfunction. Aging has been tied to mitochondrial dysfunction. And we can talk about some things that are, you know, maybe too early to talk about, but COVID, long COVID, it's tied to mitochondrial dysfunction. And I think it was really, this is the reason why I'm here talking to you about this,

because, you know, in my day job, I'm a critical care physician taking care of patients in the ICU, and so I saw firsthand what was happening, and it led me, it drove me to research more about what was going on. You know, why were my patients who were dying low with vitamin D? Why were my patients who were dying and infected with SARS-CoV-2 dying? And I started to find out that SARS-CoV-2 hits the ACE-2 receptor. And the ACE-2 is not just a receptor for the virus. It's also, it mitigates oxidative stress.

And oxidative stress is the enemy of mitochondrial function. So all of these dots started to connect for me, and I started to research this more and I found some amazing studies that have been done by individuals who are highly skilled, but they were in their silo. And I don't know if they really connected the dots. What I started to do was take research in all of these silos all across the world and start to put together a hypothesis. And at the end of the day, what I came across was that sunlight was very beneficial.

And I thought I had discovered something new. But in fact, we had known this all along. We just didn't have the scientific research. we had the empirical understanding, but not the scientific research on this. But, yeah, the data is overwhelming, and it's amazing. We can get into that. But we're going down this path trying to explain what's going on, why we're going this way, what's going on in the individual human being, and then what we can do is we can show

on an epidemiological basis what's actually happening, because the truth should be redundant. Yeah, what you said a short while ago, I think, is just worth double-clicking. I like you, I'm really passionate that at the end of this conversation, people start taking their light exposure much more seriously. You've mentioned this, and I've covered this on the podcast many times in the past, that when our mitochondria are not working well, so when we have mitochondrial dysfunction, it can cause a whole variety of different problems.

Heart disease, type 2 diabetes, obesity, dementia, inflammation, as you've mentioned, long COVID. even some cases of cancer, right? So mitochondrial dysfunction right there at the heart. And what you're saying from the research is that one of the ways in which we can address this mitochondrial dysfunction is to get large amounts of infrared light.

And the way you get that infrared light is by going outside. I would agree with that. But I would also, and there's probably some people in there thinking, oh, I need to get out there for hours, the day. It's very interesting. In my discussions with Glenn Jeffrey and Robert Fosbury, who also collaborated, who's an astrophysicist on this, is that you actually don't need to get out

and have large amounts of infrared lights to get these type of changes. Some people might out there be thinking, well, I've got very fair skin. I burn easily, or I've got a history of melanoma, or maybe I've had melanoma, or some sort of skin cancer. And here's the good news. The good news is that you don't need to have massive amounts of infrared light. You just need to have small amounts and you can get it without even being directly in the sun. I've taken some photographs and I've measured this. You can actually get outside in the shade so long as you're surrounded by a lot of trees. It's bright.

You're going to be getting much more infrared light in that environment than you are in your office. And in fact, I would even go as far as to say this. there is an aspect of infrared light called the bifasic nature of infrared light, which means that after you get enough of this infrared light, further stimulation of infrared light is actually less and less beneficial. Let me give you some examples. When Glenn Jeffrey did his studies on glucose metabolism, and he took subjects and exposed them to this type of light on their back, it was only for about 15 to 20 minutes. Glenn Jeffrey has been working with flies and humans now for decades and the mitochondria all act the same once you have about 15 to 20

minutes of this type of light this effect actually lasts for days he did an experiment on on people with difficulty with vision and just shining light into their eyes for about three minutes actually had an effect for days on the mitochondria so so it doesn't have to be for a very long time but it does have to happen. And here's where we are with the population. Look, there are some people that get outside in the sun, they're gardeners. This message for them is probably not as essential because they're out there already. But for the majority of people, and I've looked at the statistics, I think in England it's 92%. In the United States, it's 93%. That's how much time we're spending indoors away from sunlight. And so we are talking about a huge amount of the population at very one

extreme that maybe just 50 or 100 years ago, that was not the case. We were outside. We were in the sun. We were getting around. And that was enough. But now what we're talking about is people who get up in the morning, go to their car in their garage, drive to a covered parking lot, go to their office, spend the majority of the day when the sun is out inside of an office, surrounded by windows that block infrared light and lit by bulbs that don't have any infrared light, come home and they come home after the sun goes down, and they go back to their home and they expose themselves to light at night working on their computer. And this is their existence literally for weeks on end until maybe the weekend comes and the sun happens to be up and they get outside and they get some

sunlight. And so this is the existence that we're talking about. And what I'm saying is that they should make a concerted approach, a concerted effort that's very important to get outside for just literally just 20 minutes, 30 minutes if the sun is low in the sky. And to get that sunlight on their body on a daily basis, that right there can actually have a tremendous benefit on their health. It doesn't need to be sunbathing every single day. And they don't necessarily need to get light panels to do this type of work, but just getting outside in the sun on a daily basis is very important. What have you changed in your own life over the past two to three years having, you know, gone deep into this area of research? So I am a physician and my, the nature of my work

being in the hospital is shift work. So I'm in the hospital at 7 o'clock in the morning and I get out at seven o'clock at night. And the nature of that is that I'm not going to get exposed to a lot of light. So I can't keep my mouth closed about it. So I tell everyone around me. And it used to be that I would go out at lunchtime in a little patio area that had a few picnic tables. And I would always make it a point never to eat lunch in the doctor's lounge, but to get outside in the sunlight. And I always noticed that it helped rejuvenate me, gave me more energy for the afternoon. And as I started to say this more and more to other people, I found it more and more difficult to find a seat at lunchtime when I got outside because more people started to do exactly the same thing. And I started to talk to them. And they also, either because of what I told them or because they've independently researched this as well. And so I've been trying to make it a point that on my lunch breaks or any type of breaks that I have, I try to get outside. I walk around, try to get as much sunlight as I possibly can. Because our lives have have changed in the last 50 years.

We are now primarily indoor creatures who live in climate-controlled environments, who see the outside as being kind of wild, and we need more control. We don't like the heat. We don't like the cold. And that's a whole other topic about how we're not exposing ourselves

to that type of extremes, which is actually really important for our human body in terms of heat shock proteins and things. So we've basically tamed our environment down And unfortunately, because of energy efficiencies, we have eliminated that portion of the solar spectrum that we considered wasteful because it provided no visible light and wasteful because it heated up our environment. And so we've actually intentionally eliminated that type of light from our environment.

And so what's funny is, it's not funny, but it's just kind of strange, is now we have these devices that give us that back and the results are astounding right and people are like incredulous like why would this light panel make me so much more why are the studies showing this and i just have to think back you know 300 years ago imagine if we were sailors on a british ship and and um and you know i'm watching your and my gums bleed and people are falling apart and dying and someone comes to us and say hey you see this lemon all you got to do is eat this lemon and you're going to be so much much better. How could that possibly be? How could eating a lemon make us better? But, you know, I like to quote Robert Fosbury, who first said this to me. He said, you know, Roger, lack of

infrared light is the scurvy of the 21st century. Wow. Yeah, it's very profound when you put it like that. I wonder, Roger, how much do you think, if we take a step back, and look at how many of us modern humans are living. As you've said, 92, 93% of our time is spent indoor. And therefore, you and I both see this huge interest in health. People feel sick, they feel tired. They're wanting advice on how to live healthier lives. And let's take nutrition, for example. There's obviously many debates over the best diet for people to have. And some people seem to feel that they have to partaking quite restrictive diets sometimes in order to feel well. And I've seen that with patients. Sometimes actually it really works.

They cut out certain things and it actually really does help them. But if we're trying to take this big picture view, I just wonder if we're missing these natural signals that our biology has been wired to get for tens of thousands, hundreds of thousands of years, maybe the reason we're having to restrict our diets or, you know, take all this effort over our health is because we're missing this crucial macronutrient. As you say, infrared light. We're missing infrared light. So therefore, we're having to compensate. And then, I guess, going one set further, we often talk about the blue zones. And I know there's some, you know, controversy over the blue zones

around some of the literature, some of the research, but nonetheless, there do appear to be these areas around the world where people have high rates of longevity compared to their surrounding areas. And everyone's talking about diets and community and their movement and the low stress, which of course are important things. But I bet if we look at those populations,

they're also spending a ton of time outside. And they're in warm climates, a lot of them. I know Iceland isn't technically a blue zone, and I know they've got high rates of longevity, but a lot of the high longevity hotspots are in warm areas where people will naturally spend more time outside. So when you start to try and put it all together, it does start to converge on this idea

that we might be missing one of the most important ingredients for health, and it's sitting there right under our noses. Yeah, where do we begin? Look, we as human beings are a complex machine, and we intuitively know that the good care of a complex machine is not monolithic. If we have an automobile that we cherish, taking care of that automobile is not just about putting the right octane fuel in the tank. You also have to change the oil. You also have to change the air filter, rotate the tires, et cetera, et cetera. and the total care of that automobile is going to allow it to run for a long time.

And I can sit here and talk to you about sunlight, but sunlight is really only one of the eight laws of health that I like to talk about. Nutrition is one of those. So we do need to put the right things into our body. Exercise is another one, as you mentioned. Water is another one. So the free use of water is important in terms of filtering things, but not just the internal use of water,

but also the external use of water. Water is a very high-specific heat, which means that it can absorb heat and raise the temperature very little, but it can also do the opposite. It can give off a lot of heat and still keep its temperature. And so because of that property,

you're able to use it to elevate body temperature in certain situations when the body needs help to do that. That's another discussion. Sunlight is just one of those laws of health that we are talking about. What are some of the other laws of health?

Temperance, not eating too much, avoiding alcohol, smoking. As a critical care physician, I see the results of the abuse of some of these drugs. Air, fresh air. People believe that fresh air, the best type of air is air that is just nitrogen and oxygen. And I can tell you, the best actual type of air is not only oxygen and nitrogen, but also some of the phytton sites that come off of trees that actually have been shown to improve our immune system.

So walking out in nature, there's also good bacteria, just like there's good bacteria for our gut, there's also good bacteria in the air that actually can help suppress infections. So this is science that is looking at, you know, what is really good air? The best type of air is the air that you find outside. And as I mentioned before, Florence Nightingale seemed to see that empirically with her patients. And then finally, the last two would be rest. So not only good sleep and the ability to rest, not only nightly, but also taking a break every seven days and unwinding and basing yourself once again on the values and the core values that you have and being able to think about things that you're not allowed to think about during the week because it's such a high stress environment that it's good to stop. It's good to sort of after you're swimming under the water for six days to pop up and look around and see where you are and where you're going.

in life and to take restock of that. That's really important. And then finally, the last law of health, and look, we've got good research on this. And it's not, it's out of the sort of a lot of people consider this out of the scientific realm. But faith has been well shown in multiple scientific studies to actually have a benefit above and beyond community. So actual, you know, coming together, worshiping. This really has a strong focus on purpose. I know a lot of people kind of shy away from this, but if you're open to it and you look at the research, the research is there. And what I found is not all, but most of the chronic diseases that we see today and that I have to treat and I see them at the end of their lives in the ICU

is the manifestation of some violation of these eight laws of health. And I'm not against using medications. Look, when people are dying in my intensive care unit, I have to save their life. There's no amount of natural remedies that's going to take care of someone who's dead. We have to save their life. We have to use medications. We have to do the best that we can. But if I don't redirect them after we've saved their lives and show them where their illness has come about from the violation of one of these eight laws, I'm not really doing anything for them. I'm just sort of delaying the inevitable. If you want to concentrate and someone's out there listening to this podcast and they're saying, look, I'm tired of being sick,

I'm tired of being ill, I'm tired of having chronic disease, and I really want to make a change. What I would do is put out these eight pillars of health, and these are not new. These have been around for some time. In fact, there's a university just outside of Sacramento called Weimar University that's actually put these together in a mnemonic called New Start, N-E-W-S-T-A-R-T, nutrition, exercise, water, sunlight, temperance, air, rest, and trust, and put those out and look in your life, look back on your life, look where you've been, and see where you might be violating those laws of health. And those are the areas that I think we can improve on.

What I think is essential, what I like to talk about and get into the evidence for, because I'm sure people listening to this saying, okay, give us the evidence, is that first, is that S right there in the middle. And that's sunlight. And I believe, you know, it's just one of the eight laws of. health. If you keep it, it's still possible to mess up on the other. What you really need to use that car analogy is all of those eight cylinders really firing and firing to get the real power of the V8 engine that you need in your car. All of those really need to be looked at and

and addressed. Yeah, yeah, I love that. I mean, I love the passion there, Roger. I love the analogy with the car, because that's it, isn't it? You're only as good as your weakest link. So you can nail everything in your car, put on the right petrol, you know, tune up the radiator, whatever it might be. I'm not a mechanic, okay? So, but if your back rear tire is flat, it doesn't matter. Like, you can do all that. You can keep spending more money on petrol or whatever it might be. That's going to be holding you back. And I guess you're drawing an analogy saying, hey, listen, maybe you're nailing your nutrition. Maybe you are getting 10,000 steps a day. but maybe that's indoors on a treadmill, right?

Maybe the weak link at the moment is your lack of time outside. Now, we also have to acknowledge that going outside is free, okay? It's not like you have to do anything or buy anything. Of course, some people's lifestyles and their jobs make it harder for them to do it as much as they might want to. But at its core, you're talking about something that is completely free of, charge, which I think is absolutely worth remembering. I want to dive into those eight pillars for sure, and I'm very interested in some of those ones at the end there, including faith. But just going back to sunlight, again, or natural

light, I guess, on your YouTube channel, which is fantastic, on Medcram, you've done so many videos on light and, you know, gone through various trials as to when a human being exposes themselves, to certain doses of infrared lights, you can have all kinds of benefits on your health. So from the top of my memory, I can remember, one study on vision, one study on blood sugar, okay? Everyone thinks blood sugar is just to do with foods. And occasionally I'll try and persuade them

it's also to do with stress, but there's also research, isn't there, showing that actually our light exposure influences our blood sugar. So can you just go through sort of top line of some of these papers? because it really helps build the case of people as to why exposing ourselves to light is so important. Yeah, so this is the part that I really love

because once people start to see the studies, then they start to sit down and realize that this is not hyperventilation. So randomized controlled trials are the top level of evidence that we have. It gets rid of a lot of the confounders, and now it's starting to come out that we have these trials that show this.

So again, Glenn Jeffrey's study, showing the people that were exposed to infrared light, not even at their head, just in their thorax, showed that there was an improvement in the mitochondria when this was given in a randomized fashion in the eye. So these cones in the eye in the retina look at blue light, green light, and red light, and they are extremely dependent on energy

from the surrounding mitochondria in the cell, in these cones. And to the point that as these people get older, their ability to distinguish different types of red, different types of green, is limited by the amount of energy output from the mitochondria. When Glenn Jeffrey exposed them in a randomized fashion to 850 nanometers of light, he was able to demonstrate that the threshold for that color blindness significantly dropped beyond any kind of understanding or confounding that in fact this was actually working. So, peer-reviewed, published in-nature scientific reports. You said 850 nanometers of light. Just to be clear, so everyone's following this, that is in the invisible range, right? So we can't see this, okay?

But it's that infrared range. And you also say something that I think it's worth highlighting. The light was being shone on their thorax, yet it was having an impact in many areas, including their eyes. And I think in one of the videos, you spoke about this being called the abscopal effect, how mitochondria can communicate within the body. So can you speak to that? Because that is super interesting. Yes.

So we know that mitochondria can communicate not only with each other within the same organ, but can also communicate in different organs of the same human body. In fact, we actually have seen mitochondria floating, free floating around, not even in a cell, but floating around in the blood. So there is a lot of things that we don't understand, but what was clear here is that it is possible to get the benefits of sunlight in parts of the body that are not being directly exposed to the sun

in the another part of the body. That was what was really clearly shown here in this study. Yeah, absolutely incredible. It's quite interesting, is that I'm really fascinated at the moment with vision and whether it's possible to improve, our vision and improve our eyesight. And, you know, recently I covered this on a podcast with someone called Dr. Bryce Applebaum.

And I've really been thinking about this idea that, you know, our modern lives, meaning that many of us are just constantly being exposed to just near vision, whereas we've evolved out on the planes where we could actually look out into the distance and, you know, spot the predator far away. And, you know, the current research is suggesting that by 2050, 50% of the world's popular

might have myopia and therefore need some form of glasses or whatever. But there are so many case reports out there, which are absolutely convincing me that the more time we spend outside, the better multiple aspects of our health. And of course, this study showed specifically how infrared light exposure can improve certain aspects of our vision. Yes. And vision is, of course, very important. And it's what Glenn Jeffrey does because he's a professor of ophthalmology.

But realize that the reason why there was improvement in vision in that study was because that's what he was testing. We've looked at in other studies, multiple other aspects. So people have issues with cardiovascular disease, cancer. I mean, the data is there for that as well. He also, by the way, checked blood sugar. And as we talked about already, there was a 27% reduction in blood sugar after a glucose tolerance test. He published that as well. That was from red light exposure, wasn't it? Yeah, 670 in that case, red light exposure. So there seems to be this red infrared area, the near-infrared where a lot of these benefits are occurring, yes.

And I'm sorry to just keep clarifying the terminology, but I think these terms sometimes people find confusing. When you say near-infrared, what exactly do you mean by that? It's very human-centric. So near-infrared is closer to the visible spectrum. So it's that type of infrared that's just beyond red. I see. Okay. Okay, then if we just zoom out to practical things that we can do, okay, just through the lens of infrared light at the moment. Of course, the best case scenario is that we spend more time outside.

You're saying we don't spend all day. You're saying these 15 to 20 minute bouts, maybe two to three times a day if we can, gives us that exposure, okay? But of course, some people are still going to struggle to do that. And red light panels are probably one of the hottest things in wellness over the past few years. I think a few years ago there was skepticism in quite a lot of areas about the benefits. I think that skepticism is starting to change now as more and more research comes out. What is your view on red light panels and how they can help us with our health?

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It's in review right now where he took people that were in a LED environment. So in an office environment lit with LED bulbs. This is a very common scenario. It was actually at a building there at UCL. And what he did was he, in a randomized fashion, put a 60-watt incandescent light bulb, but each desk, and turned it on. in a randomized fashion and did a very similar test that we just talked about

where we measured the color blindness in these subjects. And what he found was that the presence of the incandescent bulb alone at their desk was enough to improve their vision. In other words, that incandescent bulb was giving them

enough of the infrared light to improve their vision so that they actually outperformed those people that were sitting at their desk with just an LED environment. Now, there was another study that was done where it was very similar to this, where they had, again, in an office situation, LED bulbs. And what they did was at each of these desks, they placed a red light panel, okay, similar

to the one that we're just talking about, to see whether or not it improved general wellness. And they had a number of factors, well-being. They had a number of endpoints, which escapes me at this moment. But there were definite a priori endpoints in that study. This is something that they found that was very interesting. And it's the reason for my placing sunlight above LED panels, red light panels, I should say. What they found was this. They found that there was an improvement in wellness in those subjects that had the red light panels at their desk.

but only in the wintertime. So in other words, they did this experiment throughout the year. They only found a statistical benefit. They only found effectiveness when they did it on subjects in the wintertime. So what does that tell me? It tells me that these things work when there is a paucity or a reduction in the amount of sunlight that someone is getting. So this brings up the paradox. The paradox is that sunlight is beneficial, but for any given individual, its effects are the best, are the most, are the most important, particularly and precisely at the time of year when it is the least available.

And so if that becomes an issue for someone, if they are not able to get outside because of their job or because of their abilities, and they're not able to get that light in the wintertime, we'll talk about some research about why this is really important, then yes, definitely. And look, I'm an ICU physician. I take care of patients that are too sick to even move out of their bed. So there is a need for this. But if you're a healthy individual that can be mobile and do, and you're asking the question, should I invest money in a red lamp or a panel,

or should I just go outside into the sun? To me, the answer is pretty clear. What if someone says, Roger, that's great, but I live in a place where six months of the year, it's cold, dark, rainy and cloudy, and even with the best intention, and even with you sharing all this wonderful research with me, I know what I'm like in the winter, I'm unlikely to motivate myself to go out when the weather is not so inviting. For that individual, would you say that, yeah, look, a bit like a supplement maybe, a food supplement. You know, if you're, I guess

if you're spending loads of time out on the sun all the time and you're topped up with vitamin D from the sun converting that vitamin D in your body, then you probably can have very limited benefit from vitamin D supplements because you're already topped up from your lifestyle. And I guess it's the same principle here, isn't it? It's like if you're low, if you're light deficient, then certain things like these redback panels can perhaps be useful. Do you see it like that? Yeah, absolutely. So one of the things that I learn as a physician is you can learn everything in the book, right? But you've got to meet and understand the patient that's in front of you and meet them where they are and try to figure out what's the thing that's going to work the best

in their particular situation. So you've described the situation where somebody is likely not going to be getting outside in the sun. And in this case, a panel is going to be certainly better than nothing. Look, there's several studies that have shown that the type of this type of light use is beneficial. The one that comes to mind off the top of my head is a Brazilian study where they looked at COVID patients that were admitted to the hospital. And let me just put a backstory on this. People who have COVID are very much in oxidative stress. We know that very clearly because of the ACE2 receptor. We know that their mitochondrial are damaged. We know that a lot of the issues with the blood vessels in the lungs is that the covering of those blood

vessels become so damaged because of oxidative stress that they release these factors that can cause blood clots to occur. This is all related to oxidative stress. And if you can mitigate that oxidative stress with infrared light, which is exactly what happens, then there's a hope that actually you could prevent a lot of the detrimental effects of COVID and hospitalization. So these group of researchers in Brazil did an amazing study. They actually made a light panel that you could wear. It was a jacket. It had LED lights on the inside, and it was transmitting at 940 nanometers. So that's still in the infrared spectrum, near infrared spectrum, just past the red light. It was wonderful because you didn't have to blind these people because you can't see the light anyway, right?

These are just LED bulbs. And they put it on all of the subjects. There's about 30 subjects. and randomly they would turn them on, listen to how often they got it, 15 minutes a day, once a day. That was it. We're talking about exposure to infrared light for just 15 minutes, 15 minutes, 1.5. And the intensity of the light was 2.9 milliwatts per square centimeter. That's at or below the amount of light that you would be getting from the sun. okay in that particular wavelength of infrared light so very not very high so we're talking about not very high lights for 15 minutes a day not much so after seven days they did it for seven days

they compared these two groups it was incredible every single endpoint that they looked at was statistically significant every single one of them the people who got the these were people that were admitted to the hospital that were not sick enough to be in the ICU but sick enough to be emitted requiring oxygen. Okay, COVID patients. Their oxygen improved faster. They were able to take a deeper breath faster. They were able to sustain their breath faster.

Their heart rates improve faster. Their respiratory rates improved faster. The cells in their immune system that were responsible for fighting the virus, instead of going down in the control group, they went up and actually improved. But the biggest number out of this whole study was instead of the average hospitalization for the COVID patient being 12 days,

it was cut by four days down to eight days. These patients were out of the hospital four days faster by just getting 15 minutes of essentially what was artificial sunlight. I mean, that is utterly incredible, right? Utterly incredible because we don't think about light as a nutrient like that as a as a as a drug as a medicine to use to increase the rate of discharge the speed of discharge right yeah and this is data that we've had for a long time i mean people who are closer to the window there's there's numerous studies so m iCU patients post-op patients

s icu patients cardiac patients they've done the research on all of these the ones that are closer to the window or if the window is bigger they are discharged from the high hospital faster. Can I ask on that? So that's interesting because we know, for example, if we want to make vitamin D, we know that we can't just be getting that sunlight through the window. We have to actually be outside with the sunlight on our skin. Yeah. How does that relate to those other components of light, you know, the infrared lights for our circadian rhythm, all these kind of inputs from lights? Because, you know, what happens if we're behind a window and not outside? Are we getting some benefits still or not really?

We are getting some benefits still, but not the full benefit of going outside. So that's why I'm such a proponent for leaving the structure and going outside. So here's the issue. A lot of these studies that were done looking at hospital windows were done decades ago, long before we started instituting windows. being put into buildings that had what we call low e glass. This is glass that is specifically designed to not allow infrared light into the building because that heats up the environment and increase the costs for air conditioning. So it's unclear how much of that would be true in an environment where there is the blocking of that

infrared light. Now, I don't know in England or in the UK, for instance, how often that kind of glass is used. I can tell you here where I live in Southern California, it's mandatory. It's because we have a problem here in California with homes being too hot, not with being too cold. So we've gone to one extreme to prevent the overuse of air conditioning. I could see, though, very easily in higher latitude areas where the sun actually produces heat in a good way. So you don't have to heat the house. They may not mandate that as much.

But this is still an issue. one of the ways you can find out if you're in your home whether or not your glass is a low e glass or not if it's glass that's more than 50 years old the chances of it being that type of glass are very low but another way is just simply standing in the window when the sun is coming through and if you can feel the warmth of that sun coming through that glass you are your chances are that that is not a low e glass and there's plenty of infrared light coming through although not as much as if you were to go outside. Yeah, it's interesting that as we're getting more advanced in many ways as humans,

so we can make this, you know, high-tech glass that protects us and, you know, means we have to use less energy to heat or cool down the house. We're also doing it at a huge cost to human health. And there's so many more analogies like that across society on that, as we've become more comfortable in our lives, as we've tried to make our lives more comfortable, actually our biology has really, really suffered. It's fascinating.

Yeah, and you know, Dr. Chatterjee, there's a study that just came out last year that I think many of your audience who's living in the UK would be very interested in. This was done out of the University of Edinburgh, and it was a dermatologist by the name of Dr. Richard Weller up there in Scotland, and he looked at the data bank, which is a wonderful data bank, by the way.

It's the world's envy. It's the UK Biobank, where we can get a lot of papers out of that data and statistics. What he did was he looked at, I think it was about 3 to 400,000 subjects, both men and women, living in the UK, and he looked at two things. Number one, he looked at the use in salariums. Obviously, you know that better than a lot of our American friends here over here, what a solarium is, but obviously it's, for those that don't know, it's basically these extensions off of the home that are covered in glass where you can go out and be exposed to a lot

of the light. So obviously, by definition, this is light coming through a window. But he also coupled that with shortwave radiation. They have the ability to look particularly in the UK and over a period of a year decide how much shortwave radiation is coming to that area. And what I mean by that is ultraviolet light essentially. So this is ultraviolet light we're talking about now, not infrared. But of course, when you're out in the sun, ultraviolet light is associated with infrared light as well. So all of this is coming as a package deal. Here were the findings. He found that as solar radiation went up, as solarium use went up, what went down was all-cause mortality, cancer mortality, cardiovascular mortality, and also non-skin cancer mortality.

The big question, though, that he had as a dermatologist, is, well, what about melanoma? And in that study, which is a very large study, they looked at what happened to the incidence of melanoma. And while the numbers slightly went up, it was unclear whether or not the numbers went up as a result of just by chance or whether it was statistically significant. So what we would say is that we cannot say with greater than 95% assurity that there was any rise whatsoever in melanoma incidents in a population in the UK. And I think that's actually very important because what we have now is we have definite evidence that exposure to sunlight, and we know this from the Swedish study

that was published in 2016, we know that sunlight exposure reduces the risk of all-cause mortality. It's associated with a reduction in all-cause mortality. It's associated with a reduction in cancer mortality. It's associated with a reduction in cardiovascular mortality. And yet, on the other side of this, we're not seeing a dramatic increase in the incidence of melanoma, which, of course, is a deadly skin cancer. And so Richard Weller understood. this. He actually wrote an editorial, actually a review to a major dermatological journal called the Journal of Investigative Dermatology, where he published a piece called Sunlight, Time for a Rethink. And he mentioned in that review that a number of major organizations, dermatological

organizations, even in Australia, of all places, where skin cancer is a real issue. And he showing that those organizations are now coming to the conclusion and they're realizing that avoidance of the sun is a double-edged sword and that we need to tailor our recommendations with the understanding that there is a risk-benefit ratio. I think that's a very good first step. Where I'm coming from on this is that I believe you can have your cake and eat it too. it's possible for you to get the benefits of sunlight exposure and if you're concerned about skin cancer or skin damage because of the nature of infrared light

and its ability to penetrate through clothes and its ability to reflect off of trees and be very high in your environment if you were that type of individual you could go outside on a sunny day you could sit in the shade around trees you could cover up with a layer of clothing wear long sleeves, even wear a wide-rimmed hat.

And I believe that you could get the benefits of infrared light in that environment much, much better than you would inside, even with a window. Yeah, it's really quite remarkable when you start thinking about what we've been told to fear in society and where that has come from, right? because until relatively recently, this idea that you must fully cover up in sun cream before you go out in the sun, it wasn't really a thing. And as you say, there have been some unintended consequences of that. Of course, no one's saying, go out there and get sunburns.

No. At the same time, Roger, I don't know if you've seen this. I've seen this in a patient population in the past for sure. and many colleagues of mine who practice in a way to me have also seen this that often people who used to find that they would burn a lot

when they change their lifestyle and often change their diet quite dramatically from ultra-processed foods to more minimally processed whole foods they find that they burn less, right? Yeah. Which is, you hear it enough times ago

there was something going on there. And then the follow-up question or the follow-up thought for me, which really fits with the theme of this entire conversation is that maybe the reason that the sun appears to cause problems for some of us is because we're so sunlight deficient. Maybe if we weren't so deficient as a society,

maybe if we were all getting a couple of hours of natural light exposure every day, maybe we'd have to be less worried about those potential downstream implications. Do you know what I mean? There's quite a lot to unpick there, isn't there? There is. There's a lot. And, well, where do we begin? So, look, if we look at just what happens in a day when the sun comes up in the east and then sets in the west,

because the sun, when it comes up, has to cut through so much of the atmosphere, you're getting primarily infrared-rich light and ultraviolet poor light. What is that doing? There's evidence that that light, when it's going into the skin and into the body, is causing the production of melatonin in the cells in the skin and in the body. This is the same substance that's produced from the pineal gland right before you go to sleep, but it's a very powerful antioxidant, probably produced on orders of magnitude higher than in the pineal gland, but it's produced locally, and that melatonin is being built up getting ready for the onslaught of the day.

And then when the sun goes up, 10 o'clock in the morning, 12, 2, 3, 4, that whole area there where ultraviolet radiation is coming down to do, you know, obviously some good, right? It's producing vitamin D in the skin. But remember, the skin has been bathed with this melatonin, getting ready for the onslaught. And then as the sun starts to go down, you've got melatonin once again being produced to mop up any damage, any kind of mutations that have occurred, antioxidants. And so the entire cycle of the sun, as it's going from the east to the west, has built in because of the atmosphere and because of what it does in the human body, almost like a built-in protective progression in the skin so that the damage doesn't occur as much. You can think about what might happen if you were inside the whole day and only went out at noon, which is actually what I try to do. but I try to stay in the shade and I do get out more on the weekends

to make sure I build up what some people call that sort of solar callous where you've used it and those things are in place which you don't want is someone to all of a sudden who hasn't been outside to just go outside in ultraviolet light and ultraviolet rich sunlight

and get skin burned. That's not at all what we want to see. We want to see rational, moderate, sun exposure, above and beyond what people are getting now, which is significantly less than what were we getting just even 30, 40 years ago. Yes, you described that sort of path of the sun from east to west and the various wavelengths that we get exposed to throughout the day. It's an orchestra, isn't it? It's a symphony that it's going on to prepare us and to get us ready for the next level of exposure. But we're

missing that. We're sort of missing that where the window lies. And then as you say, what often happens, it certainly happens in the UK, particularly after a long winter, you know, where the first day that it's sunny, people will literally go out all day after having had no sun or winter and then often become red or get burnt. And it's these kind of extremes, right, that could be causing the problems, whereas if we had that more low-grade solar exposure throughout the year, maybe that wouldn't happen. Maybe we'd build up that callous. We'd have, you know, that adaptation, the body would be used to it. And of course, we have to recognize that skin color and skin tone plays a role here, doesn't it? Because your skin tone and mine are very different because of our ethnicities.

And therefore, we perhaps are going to need different levels of sunlight in order to thrive. Yeah, let's think about what happened here. I mean, I think it's pretty well accepted that the human race originated probably near to the equator. I mean, there's debates about exactly where, but that would tell us that the original human beings were probably darker skinned. And as a result of that, it was probably a result of the fact that sun was coming in at the equator pretty strong. But as these populations started to migrate, think about what happened. And what you saw is that these populations that start to move further and further north or south away from the equator, they start to develop lighter skin.

Now, why would the body find the need to do that? It's, I feel, because there is the important, such, there's, the body places such an importance on light at those latitudes that it actually needs to pull back that melaton or melan and it needs to lighten the skin so that it can get the beneficial effects of vitamin D, infrared light, of course, to that degree. But clearly you can see here that there is an adaptation that is occurring within the human species as you move away from this type of bright equatorial sun that you often get. What was interesting in the study you mentioned before of Glenn Jeffrey in the offices

where they've got LED lights overhead. And I think you said that some of the participants had an incandescent bulb put in front of them, right? So nothing else changed. and just from getting that more broader exposure to all these different wavelengths of light, they started to get better health outcomes. That's quite interesting because incandescent bulbs are getting harder and harder to get hold off.

The laws are changing. What we're able to buy these days is changing. Can you just explain what LED lights are and what has been the consequence of more LED lights coming into our lives? Yeah, so LED lights are basically, well, let's back up and talk about incandescent. Incondescent bulbs are basically taking electrical energy, converting it into a thermal energy, using different types of metals and filaments, and it's creating a very broad spectrum of energy coming out of that bulb.

So there is visible light, but there's also probably the majority of the energy coming out of that bulb, is in the infrared spectrum, and there's also heat coming out as well. So that was what was invented by Thomas Edison over 100 years ago. And what has happened is we've tried to improve on that equation there. We're trying to improve on that invention by saying, instead of putting so much energy into this entire cacophony of wavelengths, since the purpose of a light bulb is to produce vision, why don't we concentrate all of that energy onto the visible spectrum

and cut out the quote-unquote wasteful amount of wavelengths? And so you have light-emitting diodes, which is the product of technology, and where you have a very exquisitely high energy efficiency where almost all of the energy that's going in is being admitted as a visible light. Okay. So that is exactly what happens with LED bulbs. You can kind of manipulate the color on those. And it really doesn't matter for the discussion that we're having because whether you have a high fidelity LED bulb, one that's more blue, one that's more yellow, it's irrelevant because in all of those cases, they by definition are going to be missing the infrared spectrum that we would normally be getting. So for the very first time in human history, human beings are now being exposed to light that only contains visible wavelengths and does not contain the infrared wavelengths.

So whether it's the sun, whether it's a candle, whether it's a fire, whether it's an incandescent bulb, all of those always co-transmitted visible and infrared together. Now, why is that important? Again, we've already showed very clearly that infrared light is beneficial in terms of mitochondrial output of ATP. And if you look at the back of someone's retina and look at it under a microscope, you will see that the cones and even the rods to some degree are highly endowed with mitochondria. In fact, it's the one tissue of the human body that has the highest concentration of mitochondria. And the reason is, is because what the retina has to do is it has to

converts photoelectric energy into neurochemical transmitters that send signals back to the brain. And that has to be done rapidly and rapidly updated so that the brain can know literally by the millisecond what it is that's going on in the environment. That takes a tremendous amount of energy. And so you have two components here in the back of the retina. You have the components that are sensing the visible light. And you have the components that are generally the energy so that those sensors can do their job. And obviously, visible light is important for the sensors, but the non-visible infrared light is important for the energy generators.

And so now what we have is a situation where we are essentially asking the retina to make bricks without straw. We're giving them visible light. We're giving them a load to do, work on. But we're not giving them the light that we have enjoyed for malice. And now for the first time, that light that we are exposing our eyes to does not have that infrared light to support and to nurture the mitochondrial activity that is required. And so when you see these studies that Glenn Jeffrey publishes where he's adding light bulbs

to the environment, which are incandescent light bulbs, which have infrared, or he's shining specifically infrared light into those people's bodies, as we talked about in the first study. What we're seeing, and you shouldn't be surprised, that now that we're supplying the nutrients to the energy producers, obviously these sensors can now work at a higher level and the amount of red color blindness, green color blindness, and blue color blindness is going to drop significantly, which is exactly what it showed. What are these screens doing to the light spectrum that we're being exposed to? Yeah, so the screens do have. all sorts of light and particularly blue, it's not so much the issue of whether there is

infrared or not infrared, although that is a problem. Certainly you're not getting any infrared light coming from the screens. But the issue is when we're using the screens. So are we using the screens during the day or are we using the screens at night? And that comes down to a circadian issue. So use of light at night, whereas light is your friend. during the day. We've spent the whole time talking about how the benefits of light are, and we should put a caveat on that. We should really say that all of these benefits will only occur if really you're doing it when the sun is up. If you start to expose the body to light when the sun is down, that has the opposite effect. It shuts down melatonin production in the pineal gland.

It increases the risk of cardiovascular disease. It increases the risk of cancer. We know that very well. We actually have very good studies that show this. There's actually recently a beautiful paper that was published in the proceeds of the National Academy of Sciences in its title, Dark Days and Bright Nights. And this was an amazing study if I tell you about it. They gave everybody a watch with a light sensor on it. And they stratified everybody based on a Gaussian distribution. Who were the people at a particular hour that were getting more than 90% of the light sensor?

light of the population, and who were the people that were getting less than 50% of the light in that population? And what they did was they compared them at every individual hour. So they had a graph, and it started at 4 o'clock in the afternoon, and it went to 3 o'clock in the afternoon the next day. And they said, at each one of these hours, okay, in this hour, at 4 o'clock in the afternoon, who are the people that had greater than 95% of the light exposure at that hour, and who are the people that had less than 50? Okay, we followed them now for 10 or 20 years. Who died? And what was the risk? What was the associative risk? And so they showed it. And they showed that at 4 o'clock in the afternoon, if you're getting in the 95th percentile, 90 to 95 percentile of light coming to your body

as detected by the watch, your risk of dying compared to the people who got less than 50 percent was less than one. Okay? In other words, you had a lower risk of dying if you're exposed to light at 4 o'clock in the afternoon. Then they did 5 o'clock, 6 o'clock. And this trend continued all the way to about 9, 10, 11 o'clock at night. And then something happened. It jumped over one and went higher than one. In other words, people passed 11, 12 o'clock at night who had greater than 90% of the lights of that population compared to people who were getting less than 50 had an increased risk of dying at that time. And that continued until about 5 or 6 o'clock in the morning,

then it made a quick drop down below one, and now light once again was no longer a liability. It was now a benefit. It was an amazing study. So light is medicine depending on when you get that light. But one thing you said there, Roger, which I just want to clarify, you're saying even at 10 p.m. and 11 p.m., exposure to light can perhaps be helpful. I mean, you're not recommending people necessarily get their laptops out at 11 p.m. and expose themselves to lots of blue light. I don't think we can take that conclusion from that, can we?

No, the benefits were diminishing rapidly. And what happened was it started to go above one by the time you hit 10 or 11. There's other issues that happen when you expose your eyes to bright light at night, and that is that it can delay your circadian rhythm. And that's a real problem. So again, as they went from, well, I didn't say this before, but I'll add this, as they went from 90 percentile and up to 80 percentile and up to 70 percentile and up, they looked at different graphs, the magnitude of the difference started to become diminished. So this study told me two things. It told me the first thing was, is that light can be a benefit or a liability depending on

when it happens. Okay? And the number two is, and this is really dear to my heart because as a critical care physician, sometimes I have no choice, but I have to go in and take care of patients at night and I have to do night shifts. But what it told me was that that magnitude of benefit and risk was diminished in both directions when the brightness of the light was diminished. So if I have to go in at night and I have to see patients, I'm going to make sure that I'm in. a dark room or it's dimly lit or I turn down the brightness as much as possible because that makes a difference. It's not an all or nothing. And so I do believe that that's important for people who work night shifts. It's different if they are daytime people who occasionally do night shift in that situation night shift could be detrimental versus people who are on night shift all the time and they continue that trend the whole time. And it's really important that if they're going to do that, that they make sure that even on their days off, they are continuing to maintain their

dark light cycle. And of course, there's some things that you have to do. You have to make sure that your room is completely dark when you're sleeping during the day, that there's no light coming in. Sometimes you have to use aluminum foil around the windows. You have to get some sort of bright light exposure during the night to make sure that your circadian rhythm is in line. And I'll say this here because this recently just came out. It seems as though what's very important in terms of minimizing the cardiovascular risk from doing nighttime work is that you do not eat at night. So this was a very elegant study that they showed that people who they took normal subjects, they converted them into night shift workers for the study. And they showed very elegantly

that the best time to eat is actually after you're done with your night shift and you go home and you sleep and you intermittently eat during your sleep time and then go back to work and don't eat at all on your night shift because that confuses the peripheral clocks with the central clocks. Very elegant study. They were almost able to completely eliminate a lot of the metabolic problems seen with diabetes, for instance, in cardiovascular disease in terms of a short-term markers for surrogates in that study. So since we're on that topic, I just thought I'd mention that. Yeah, super interesting and very, very helpful, of course, to people who do work night shift. There's quite a lot of research now showing us, as you've just outlined, but many more papers

that the more light exposure we get at night, the worse are health outcomes. I think I've heard you talk before about a 2023 China study where they looked from satellites at how much light people were being exposed to. And the more light you would have been exposed to the night, the greater your risk of all-caused mortality, which was quite profound. Yeah, exactly. The other thing about it, too, it's even worse than that, because what we're seeing in these cities where we're using LED bulbs to light up, I mean, it's cheaper now to do it, right?

Because you don't use as much electricity. You can leave it on all the time, and it's actually going to use up less electricity. The problem is that photosynthesis is dependent on visible, light. It's blue and red somewhere in that area. And so what you're seeing is plants in the environment that are being subject to the light from LED bulbs outside are starting to become thicker. And interestingly, the insects that are supposed to eat these leaves on a regular basis to survive can't do it because it's too tough. And so what we're seeing is we're seeing a collapse in the populations of insects in these cities where these insects are not able to eat

any more food or less food because of the light on these trees. It's things that you wouldn't even think about that there are complications when you disturb the natural rhythm of light in the environment. Yeah. Unintended consequences of humans taking over the planets. There's another one. One of the things that has concerned me, the most of the most of the most in terms of public health, but specifically children's health over the past years, is the introduction of screens into classrooms. And in particular, the fact that a lot of kids now across the world have to do their homework in the evenings on bright screens. From all the research you've done and all your clinical experience, what is your perspective?

on that? Yeah, it's not good. So we know that people who are blind because there is an interruption in the, from the retina to the back of the brain where the melatonin is produced, they have less, 30% less cancer rates. And it could very well be because there's no amount of light at night that's going to shut down their melatonin production because the nerves are severed. And so what does this tell you? It sort of reinforces this idea that light at night, especially in individuals such as children, who need to have more hours of sleep than we do, right? We can get by on, I mean, ideally we should be getting seven to eight hours of sleep. For children in school, they should be getting close to nine or ten hours of sleep a night.

And so, you know, they're the ones that are staying up late. I mean, I have kids who are in high school. And what you've just mentioned is exactly what is happening in their situation. They are expected to have, in some of the classes, they are expected to have phones to be able to complete the homework because there's something online that they have to do. In other than the classes, they're expected to turn in their phone before the class begins because the teacher doesn't want distractions. I think that's actually appropriate. But when they get home, a lot of these assignments are turned in on electronics. So it's almost like it's like you can't even get into the game without having some sort of a handheld electronic device. Let's not even talk about the fact that the fact that they have an electronic device now allows them much more ease to get on social media.

And a whole host of other issues there that allows bullying, that allows, you know, that leads to depression. So there is a whole Pandora's box here where we have gone from using instead of paper and a soft light at night to screens. And there's actually a study that looked at this very topic where they compared a Kindle. So we're not even talking about like an iPad or a smart device, which is fairly bright. Kindles are not as bright, but they compared a Kindle device at night to reading a book with a soft incandescent bulb. And the display on how much light was coming to the eye was tremendous. The difference between those two. But they went beyond that.

They actually looked at how fast these people were able to fall asleep. And there was a statistically significant difference. And it was like 15 minutes versus 24 minutes. And that might not sound like a lot, but when you're trying to fall asleep and you have a reduction of melatonin as a result of that light exposure, that's a huge difference. So think about the kids exposing their own. eyes to light, thinking about their circadian rhythm being delayed, and they still have to wake up at the same hour the next morning to get to school. And so what you're seeing is a reduction in the much-needed sleep that these individuals need, these young children need who

are developing. I mean, their brains are developing. And when they don't get that sleep, we know, based on years of research, that that is associated with, you know, bad metabolic issues, obesity, inability to learn, and all of these sort of things. I think it's arguably the biggest public health emergency that's out there at the moment that's just sort of insidiously crept in. We need to be protecting our children and our teenagers. And you are literally working against one of the most fundamental principles of circadian biology, which is loads of light in the day, not much light at night,

when you are asking children to be on screens in the evening. And I've been talking before the summer with some local head teachers, and I said, listen, there's multiple issues here. There's the content, there's access to social media. But one thing that I think would have a profound impact immediately is just not to give children homework on screens, because at least then, they don't have to be exposed to bright light in the evenings. You'd improve sleep.

if they improve sleep, that will naturally improve mental health. And I could go on. Okay, Roger, in terms of then practical things that people can do, okay? So so far, you have beautifully made the case that we are a light deficient population, and that is having serious consequences on our short term and our long-term health. So there's been some practical things throughout the conversation,

I wonder if we could just really focus for the next few minutes on what are the things then you recommend people do to try and mitigate this? Absolutely. I believe that people need to get outside in any way they possibly can. If they're concerned about direct sunlight damaging their skin, they can cover up. And to get outside and just sit or exercise if they want to in an outside environment for at least 15 to 20 minutes a day, the best time of day to do that would be in the morning time.

And the reason for that is because you're killing two birds with one stone. Not only are you getting the benefits of infrared light, which are bountiful in the morning, but you're also getting the visible light into your eyes, and it's causing the benefits in terms of depression and also in terms of setting the circadian rhythm in order. So that's sort of a double whammy. I understand, though, that for many people, they cannot do that. And so for people who get up early in the morning and are not being exposed to the sun early in the morning and have to do it later in the day, that's perfectly fine. What I would recommend doing, especially at high latitudes where you are there in the UK and also in Canada and the parts of Europe, is to get something called a SAD box or a sad box.

And what does this stands for? It stands for seasonal affective disorder. It's very inexpensive. You can probably get these for about 20 bucks online. And the key here is that it needs to be 10,000 luxe giving visible light. It sets about 30 centimeters from your face and you're in front of it for about 20 minutes a day. You can also buy glasses that can do something very similar that can put that kind of light into the eyes. This is not a substitute for going out in the sun because it will not give you any infrared light.

However, it will help with the issue of seasonal affective disorder and circadian rhythm issues. So if you do this in the morning, this does not in any way make up for vitamin D from the sun. So if you need to supplement with vitamin D because you're not getting outside enough, you should do that. And it doesn't make up for the benefits of infrared light from the sun. So you still need to get outside during the day. But that light later in the day is not going to be beneficial in terms of depression and circadian. rhythm unless it's done in the morning, and so we're trying to substitute for that with the visible light in the morning time. So that's the key for sunlight exposure. And then the other

aspect is, is really after 9 o'clock at night, we should be making a concerted effort to turn off lights, especially lights that are overhead, because the receptors for this type of light are in the inferior portion of the retina, and they pick up particularly on overhead lighting. So if you want to, or have to keep lights low, keep them low in intensity, but also low in the position of the home if it's possible. And if it's really the best that you can do, turn them off completely. Don't go on screens unless you can help it. If you do have to go on screens, then make sure it's tuned away from the blue and more to a red. But again, the best thing would be no lights. The second best thing would be no blue light and more of a red light, a filter, but there's evidence that that

really is not as good as no light at all. And then, of course, the worst thing to do is just to turn all the lights on and keep the lights going and have that impact on your human body for long periods of time. Those are really, I think, the key interactive things that are beneficial, not just acutely, but also in the long run. And let me just sort of give some evidence here for this, because I think this is important. There was a study that was done at Oxford in congruence with Leiden University where they had people draw blood throughout the year. And they measured their insulin sensitivity and their triglycerides.

And what they found was when they looked at the weather report in the previous seven days, by the hour, the more sunlight that was in the weather report in the past seven days predicted how their insulin sensitivity would be and their triglycerides. Specifically, more sunlight translated into lower triglycerides and higher insulin sensitivity. That was literally within seven days. So as somebody is listening to this and saying, look, I'm going to make a change starting today, we have actual evidence that shows that we will start to see changes within the first seven days. In fact, we have information based on Glenn Jeffrey that literally within the first few minutes

in terms of vision, we can start to see improvements after about 15 minutes of light. Now, what about long term? Do we have evidence for long term? I would challenge anyone listening to this podcast to simply go to a great, graph that is easily available at your public health department for your nation that would show based on the day of the year throughout the year, where do we see the maximum number of deaths from cardiovascular disease, from pneumonia, from kidney disease, from dementia, all these infectious and non-infectious diseases. And you will see a pattern. It's clear as day in all of

the countries that are far enough away from the equator. The pattern is that the majority of the death, the peak of deaths, is one to three weeks after the shortest day of the year, so in December, for those in the Northern Hemisphere, and the lowest, it's when the hospitals are the least impacted, when you have the least amount of people on your service in the ICU, as I can tell you, is one to three weeks after the longest day of the year. It's in July. And we see this pattern every single year. And what do I take from that? I take from that, this, that sunlight impacts not only the health in terms of our vision. It impacts our cardiovascular health.

It impacts our ability to fight infections. It helps with our kidneys. This is why I struggled a little bit with the very first question that you gave me is, what are the symptoms of somebody who is lacking sunlight? And when I see that all of these diseases literally in unison go up

at the same time of the year after the shortest day of the year, and they all go down and then reach the lowest point, one to three weeks after the longest day of the year. It tells me that sunlight impacts so much of our health, that it's really difficult to pinpoint exactly where it is. So what we see here is we see short-term benefits, we see long-term benefits in terms of survival, and there are some very simple, inexpensive interventions that we can all do to make an effect.

And I'll end this little section with this. we are headed right now into the winter season. The sun is starting to pull back away from the northern hemisphere. If history is any determinant, if last year is any determinant, if all of the years that we've ever measured this is any determinant, we are going to start to see an increase in flu, RSV, cardiac deaths. Look, we actually see more cardiac deaths, a difference in cardiac deaths during the flu season than total flu deaths, period.

That's how much of an increase we see. We don't call it the cardiac season. We call it the flu season because flu goes to zero. But as we are headed into this part of the year, one of the things that we can do to reduce the incidence of a lot of these problems is to work hard, even though it's going to be difficult to do, to get outside and to expose ourselves to sunlight. Let me just give you one study just to finish this up. Harvard Kennedy School, this is the political school of Harvard, did a study back in

2021. And they looked back at the flu virus and where it hit. And they were able to use CDC solar radiation data and also the incidence of flu. And they looked at 2009 specifically because the flu that year came a little bit early. So they were able to uncouple temperature, which is cold in December and warm in July, from sunlight, which is low in December and high in July, of course. And after they looked at all of this and did the correlative studies and did the multi-regression analysis, they came up and they had this conclusion. Sunlight is strongly protective against influenza. And when I saw that and I started to put all of these things together, it became very clear to me that one of the things that we are missing more and more of, especially since the pandemic, since we've become so accustomed to staying at home now and having. having things come to us and staying inside of our homes and not going outside is that we are not

getting enough sunlight and so much disease and arthritis and inflammation and all of these diseases are as a result of us not getting enough sun exposure. We should double our efforts this winter to make sure that we're getting 15 to 20 minutes of sunlight. That's all I'm asking. Not sunbathing, no sun burning, just getting out into the sun to get that beneficial health that we all have had in the summer, but we're lacking in the wintertime. Oh, what a passionate plea for more time outside. You know, that's interesting, Roger, isn't it, about metabolic health? You mentioned insulin sensitivity and triglyceride. So improved insulin sensitivity, lower triglycerides. These are very good things for our metabolic health. And you're saying that that was heavily correlated with the

amount of sunlight exposure one was receiving in the seven days prior to the blood test, right? That has such widespread implications, because if we're trying to help people with their metabolic health, which I'm often talking about on this show, you cover on your Medcram channel, right? We're often talking about diet and exercise. And as you say, with your eight pillars of health, of course, those two things are important. At the same time, do not negate. light exposure, getting outside, will also help you with your metabolic health. And just a couple of things just to make sure we've sort of hammered home. We have been saying sunlight a lot throughout this conversation.

And I just want to make sure it doesn't get misinterpreted by anyone. I think you're saying get outside. Ideally, sunlight. But of course, if you're living somewhere where it's cloudy for three weeks, you're still saying get outside because you will still be getting some of these benefits even if you can't see the sun. Absolutely. So just to give you an idea, we measure the intensity of light, visible light, which correlates to invisible light as well, in measurements of lux. So right now in the room that I'm in, any room that you're in in your house can range between

50 and 100 lux. If you go outside on a bright, sunny day, it's about 100. thousand luxe okay so it's about you know multiple times higher that you're seeing a thousand times higher on a cloudy day it may be 20 to 30 thousand lux okay so that's still magnitudes of order higher amount of sunlight than you're getting if you stay inside your home yeah wow and you know on the subject of light in the day and darkness at night i think my family think i'm quite militant at the moment because I'm literally, I'm so, you know, with the kids are going to the bathroom in the evenings to brush the teeth, I'm like, get those lights off, you know, the bright LED lights. I set them really low and then someone's like ramp them right up. So I'm thinking of

getting them removed, but I've actually got these sensor red lights in the hallway. So when you're walking around, it's just gorgeous, it's a low, warm light. I've got full spectrum bulbs and everyone's bedside tables. I mean, I'm very protective at home of our light environment and the evening as much as possible. It makes a massive difference. Yeah, you can see it from the evidence, but you can also feel it. You know, you can feel the warmth and a calm when you have that sort of lighting at home. And it doesn't have to be that expensive. Roger, I did want to cover, there's a study I've heard you talk about before to do with the planting of green trees and the impact it had on high sensitivity CRP.

I wonder if you could finish off by outlining that study and the implications for us. Yes, and to get a visual on this, I would invite anybody listening to this to go to Google and type in infrared photography, and when it comes up and you see what infrared photography does, notice the trees, notice the green leaves, and you will see that they are highly reflective of infrared light. Now, that's not all that they are useful for. As we talked about with air, which is part of that new start, they also give off phytochemicals that could actually have an impact on our health,

and that's kind of involved with forest bathing. But for many years, we have had studies that have clearly showed that people who live in green spaces will have a reduction in diabetes. I mean, 20 to 30% reduction in diabetes, 20% reduction in all-cause mortality. 20 to 30% reduction in cardiovascular mortality. And so people have touted green spaces is something that we need to do. But the scientists who sort of criticize those studies say, look, people who live in green spaces

are higher socioeconomic classes. They have more money. They have better access to health care. This is the reason they have less of all of these bad things. So I love this study because it really puts a stake through the heart of that argument. What happened in South Louisville, Kentucky is in this four-square-mile area, this is an urban sprawl in South Louisville, Kentucky. It's called the Green Heart Project, if you want to look this up, recently published last year, actually. They had this bold vision of going through the neighborhood, this four-square-mile area, and planting 8,000 trees.

Now, these are not little saplings that you pick up at your home improvement place. These were full, mature trees with leaves already on them. Can you imagine how that changed that environment so dramatically? And what they did was they took about 745 people before they started doing the planting. And they measured this marker called Highly Sensitive CRP, which is a surrogate marker that looks and is predictive of bad outcomes like heart attacks and strokes and things of that nature. Basically, it's a measure of inflammation in the body. And we know, we talked about this already, that inflammation is based somewhat on mitochondrial dysfunction, and that has linked to the diabetes and obesity and all of these things.

So they measure the highly sensitive CRP levels. So it takes about two to three years, and they plant these 8,000 trees, all sorts of trees. And then they come back to the same 745 people, and they re-check their highly sensitive CRP levels after two to three years of these trees being in place. And again, they did not institute, you know, mandatory income. They did not institute an exercise program. They did not change their socioeconomic class. They didn't change any of that stuff.

Same people, same environment except for the trees, living in the same place, ostensibly having the same income. And, of course, they did all of the analysis and all of that. What did they find? There was a 13 on average to 20% reduced. reduction in CRP levels. Now, that's huge from a statistical standpoint.

But what that actually translates into is about a 15% all-cause reduction in strokes, a reduction in cardiovascular disease. And this is just from planting trees, which we know are highly reflective of infrared light. What do I believe was happening? I believe obviously their environment looked better. Perhaps maybe even they wanted to go outside more. But here's the key, I think, that happens is when you, the time that you do spend outside, when you have trees and plants in your environment, and you'll see this when you look up these

images on Google, you will see so much light and infrared light coming from these trees. These trees looks like they were designed to be infrared mirrors that are highly reflective of light in that environment. And I am convinced that when we live in spaces that are green and we go outside to enjoy those spaces, there are probably multiple levels of benefits that we're having. One of the ones that I'm convinced of, based on all of this data and research, is one of them is a bountiful, plenty amount of infrared light that you don't need to be in direct sunlight. You can be in the shade, you can be sitting there amongst the trees, and you're getting the benefits of this infrared light that we've been talking about today. Yeah, just an incredible study, and I think just sort of closing off our conversation, the three key messages are immerse yourself in nature, get outside as often as you can,

turn off the lights at night, is, I guess, one way that we could try and summarize some of the practical natures of this conversation. Roger, look, this is the third time you've come on my show. I really enjoy talking to you. You're such a knowledgeable doctor, but also so passionate. I love the way you communicate these ideas. I love the way you dedicate yourself to making the videos on your MedCram YouTube channel so helpful for so many people. If people want to follow you and sort of find out more about you, where would you direct them to go? Yeah, so we have a YouTube

channel called MedCram, M-E-D-C-R-A-M, and that's where I post maybe about once, twice, maybe three times per month, some pretty high-quality videos where we go through this data. I'm probably on a daily basis active on X. And you can follow there, it's just my name at Roger Schwellt. But we also have a website called Medcram.com, where we actually go over some of the sunlight aspects. And we have resources for medical professionals who can get continuing education credits through our company. And that's available as well. Roger, a huge amount of gratitude from me to you for making time and sharing your wisdom with my audience. And I very much look forward to the next time. Thank you so much.

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