The 15-Minute Fix: Why Your Body Craves Daily Sunlight

Added: 2026-06-01

[00:00:00]There was a study in 2011 in Sweden.

[00:00:03]>> Yes.

[00:00:04]>> Is that linked to this?

[00:00:05]>> No, this is a completely different study, but that that's also a very important study. So, the Swedish study is is is groundbreaking. Um this was a study where they asked 20,000 20 to 30,000 Swedish women about their habits in sunlight.

[00:00:21]And they divided these women into three categories. Those women that did not get a lot of sun, those that got a moderate amount of sun, and those that got a lot of sun. And they followed them for 20 years. And they they kept a track of each one that died and what they died of.

[00:00:37]And when they were done with that, they were astonished because what they found was that the women who had spent most spent the large amount of their time outside or that spent the most amount of time outside had the least amount of mortality from cancer, from cardiovascular disease, and non-cardiovascular disease. And those that spent the least amount of time outside had the highest levels of that.

[00:01:01]The magnitude difference between those two was so much that they were able to show that women who in Sweden who spent the most amount of time outside and smoked had the same mortality as those women that did not spend as much time outside and did not smoke.

[00:01:24]>> They were equal.

[00:01:25]>> They were equal. In other words, being in that category of not spending much time outside in the sun was the same risk factor for death as smoking.

[00:01:35]>> How do they know it wasn't linked to exercise? How are they able to establish causation cuz that's a >> You're absolutely That's an excellent question. So, the the difference here as you go up is this is a this is an association study, okay? So, the the question is is how can you get causation from association? You can't.

[00:01:53]But, if you look at the Bradford Hill criteria, there is a way that you can potentially make a a strong argument for causation if there's something called a dose-response curve. In other words, if you can show you're not just comparing two things, but you're comparing three or more, if you can show that as you increase the variable, that there is a change in the the output, that is strongly suggestive of potentially causation. By the way, this is exactly what we did to show that smoking causes lung cancer. Obviously, we can't do a randomized control trial.

[00:02:27]Here, you get to smoke, you don't get to smoke. We'll follow up in 20 years to see who has lung cancer. This is exactly what we did. We showed that that there was such a strong association with cancer risk with smoking that we were able to say through association that smoking causes lung cancer. By the way, Richard Weller, who's a dermatologist in England, uh did just last year a very similar study as to the Swedish study, except it was 10 times bigger, and he did it with both men and women.

[00:02:55]He found the same results.

[00:02:58]It was a UK Biobank study.

[00:03:00]>> What did he discover?

[00:03:01]>> He discovered that either from from solariums or from um or being outside, using solar radiation data, uh he was able to show both on their their questionnaire and also where they lived that the more light that they had, the lower their risk as of of um mortality uh and um and and cancer mortality. So, the question was does it increase melanoma?

[00:03:29]>> What's What's melanoma?

[00:03:31]>> Melanoma is is a skin cancer. So, that's the big risk. That's the big risk that everybody's concerned about. You go out into the sun, you're going to get skin cancer.

[00:03:38]And he was able to show in that study, this was like three three 400,000 people in this study. UK Biobank study, Richard Weller.

[00:03:47]He was able to show that there was no increased there's no statistical increased risk of melanoma incidence, but there was a reduction in non-skin cancer mortality.

[00:04:01]Okay, so so here's the trade-off. If you want to go out into the sun in England, okay?

[00:04:08]The benefits are you're going to have a reduction in non-skin cancer mortality.

[00:04:14]>> So, everything other than skin cancer.

[00:04:16]>> Correct.

[00:04:17]On the other hand, there's no increase in melanoma incidence. So, that caused him to write an a an op-ed and publish it. And actually, you can look up this op-ed. It's a great op-ed. Uh it published in a um in the Journal of Investigative Dermatology called Sunlight: Time for a Rethink. Where he goes through the arguments. And he's actually shown and and there's been a number of changes that people have making around the globe. So, public health uh organizations that are saying now, you know, before we have said that, you know, the s- the sun is a deadly laser.

[00:04:53]And you should avoid it at all costs. We may need to rethink that.

[00:04:57]>> So, you're telling me that essentially 15 minutes in the sun every day turns on a switch in my body that improves my mitochondrial function, which is going to impact a variety of different parts of my health. Is that essentially what you're saying?

[00:05:11]>> Essentially, yes. And And we're looking And this is in an environment where where we are spending less and less and less time.

[00:05:19]To give To give you To put in perspective, if we were on a British ship 300 years ago, and I came to you and I said, "Do you see this little yellow fruit? Just by eating a little bit of this yellow fruit, all of this disease that you're seeing around you with your fellow shipmates is going to go away." That That would seem almost incredulous, right? But that's exactly the case.

[00:05:39]We We are the scurvy of the 21st century is the lack of sunlight.

[00:05:45]Everything is inside.

[00:05:48]Uh we we avoid the outside. We avoid discomfort. We avoid high temperatures.

[00:05:52]We avoid low temperatures. We We used to go out and play sports. We now are are playing virtual sports on on pads.

[00:06:01]We have windows that are specifically designed, especially here in Southern California, to eliminate infrared lights. Because why? Infrared lights comes in and it heats up. One of the interesting things We didn't mention this about infrared light is the way that we interact with infrared light. You can You can tell this on your own. You go outside and close your eyes. You can tell which side of your body the sun is on. And the reason is is because that infrared light not only can penetrate through your body, it's also penetrating through clothes.

[00:06:32]Very easily. And you can feel that. That That heat that you're feeling is the infrared light going through the going through the clothes, going through the skin, and interacting with your heat receptors that are well below the surface.

[00:06:44]Um so you get all of this.

[00:06:47]>> How long does the average American spend indoors? The average Brit spend indoors?

[00:06:51]>> Good question. They're almost identical.

[00:06:54]Uh I think the Brits spend a little bit more time outside than Americans. The The last number for Americans was 93% and uh Brits is 92%.

[00:07:03]>> Were we born to be outside?

[00:07:04]>> I think so.

[00:07:06]>> You think our ancestors probably spent a huge amount of time outside?

[00:07:08]>> Yeah. And And if you think about when I say outside, that also brings into play a a number of other of the new start uh letters that we haven't talked about. Uh exercise. You're much more likely to do good exercise outside. You're much more likely to get air. That's That's the right type of air outside.

[00:07:27]The other aspect about infrared light, briefly, is that trees are highly reflective of infrared light.

[00:07:34]In other words, if you're in an environment where there are trees are present, you're going to get much more of this beneficial infrared light than if you're in a concrete jungle.

[00:07:44]So so So plants like this In fact, the way that we measure the the forestation of the Amazon is through satellite imaging that looks at infrared light because it reflects infrared light back. So, the best thing best situation to be in is to be outside on a green on a day where where there's lots of green trees. We've known for We've known for decades that people who live in green spaces do much better in terms of diabetes, do much better in terms of hypertension, mortality, all of these things.

[00:08:18]>> Depression.

[00:08:18]>> Depression, all of these things, yeah.

[00:08:20]And And when you think about this, um you you bring up a point in terms of of correlation. How do we know it's not depression? We used to say, "Well, people who live in green spaces have more money.

[00:08:32]They people have they have more access to things. Maybe that's what we're seeing."

[00:08:36]I just have to tell you this study.

[00:08:37]There was something called the Green Heart Study in South Louisville, Kentucky. They did an amazing thing.

[00:08:42]They took this 4-square-mile area in South Louisville, Kentucky, urbanized area, and they measured everybody's hs-CRP.

[00:08:52]What is hs-CRP? Highly sensitive C-reactive protein. It's a marker of inflammation, and it's been correlated to bad things like stroke and heart attack. So, if you have high levels of of CRP, that's not good.

[00:09:08]So, they measured every They measured about 700 people.

[00:09:11]And then they did something extraordinary. They purchased 8,000 mature trees, dug holes, and planted 8,000 trees into 4-square-mile area. And these are trees with leaves on them.

[00:09:26]2 years later they come back and they measure all 700 people in their study, repeat the HRCRP.

[00:09:32]Dropped by 13 to 20%, which correlated to about a 10 to 15% reduction in strokes.

[00:09:39]These people didn't change their socioeconomic status. They didn't institute an exercise program.

[00:09:45]And so really it kind of shoots in the heart the idea that the advantage that we see with green spaces has to do with something else that we're not measuring.

[00:09:54]I actually believe that we'll talk about fresh air, too, that things like these plants, but much bigger. This is kind of like a bonsai plant. That's But trees outside, they actually have a benefit and what they represent, again, is these things that don't leverage the other parts of your body in in terms of the chains uh that make all of the chains bigger cuz they're they're they're they're having a benefit. But you can't get the benefit of this if you're inside a house.

[00:10:25]>> So what should we do about this in terms of how what changes should I make in my life to capitalize on this? Um this is a this brand here is called Boncharge.

[00:10:35]They do these these red light devices.

[00:10:37]They do like red light saunas, blankets, um masks. They're actually a sponsor of mine because I I started wearing this and I think they they found out.

[00:10:45]>> [laughter] >> And I started wearing it because of my girlfriend.

[00:10:48]Uh she was wearing it every day and I got curious and so I as I always do I'm always super skeptical.

[00:10:52]>> Sure.

[00:10:52]>> So I went on online and started looking at some of the research and I was shocked.

[00:10:56]>> Yeah.

[00:10:56]>> It made no intuitive sense to me that a a red light mask or any like red light device could have a profound like a what I see as a profound impact on my health.

[00:11:04]Like I didn't believe it.

[00:11:05]>> Yes.

[00:11:05]>> To start with. It was like woo-woo stuff to me.

[00:11:07]>> Uh I yeah.

[00:11:08]>> But I couldn't disprove it.

[00:11:09]>> Right.

[00:11:10]>> All the studies, many of which you've referenced, um supported that it was having a profound impact. And as I've said on this podcast before, my girlfriend's always right.

[00:11:17]>> [laughter] >> She's like always ahead of the curve and always right. So I started wearing her mask and now I have my own from Boncharge.

[00:11:22]>> Yeah.

[00:11:23]>> Do you recommend these kinds of things?

[00:11:25]>> I I think it's reasonable to do. I I will say this. Um if you are getting enough infrared light from the sun, What we find in studies, not particularly with the mask, but we find in other things is that these these other areas don't have as much efficacy.

[00:11:41]It's almost to say, if you're on a ship with a bunch of people with scurvy and you already have a diet that's rich in vegetables and fruits, eating an extra lemon is not going to be that beneficial.

[00:11:49]>> So, what do you do?

[00:11:50]>> Like a lot of doctors do, we have shifts that go from 7:00 a.m. to 7:00 p.m. So, you're in the hospital, you're not going to get outside. So, at lunch, I try to get outside as much as I possibly can into the sun for my 15 minutes.

[00:12:02]>> What if you live in a cloudy country?

[00:12:04]>> So, that's a good point. Uh clouds, because they are water molecules, will absorb a lot of the infrared light. And the problem is is that that's the exactly the type of light that you want to get. However, even on a cloudy day, being outside, you're going to get more infrared light than if you were inside.

[00:12:23]>> Okay, so I still get the light I need when it's cloudy, but I just don't get a lot.

[00:12:30]>> Yes, exactly.

[00:12:31]>> Is there anything I can do to get even if it's super cloudy and I know I'm going to be indoors?

[00:12:36]What do I do then?

[00:12:37]>> Yeah. So, the light the type of lights that we have inside >> Like these ones?

[00:12:42]>> Like these. Uh and and and actually, I think the UK and the United States are very similar in this regard, is that we really can't get the old incandescent bulbs. We're on LED or or fluorescent.

[00:12:53]And if you think about what they've done in terms of of these bulbs, the old incandescent bulbs used to give you a very broad uh spectrum. So, all the way from, you know, just near blue all the way down into the into the infrared. The way that they've made the bulbs more efficient, they said, "Hey, let's stop using energy to give off this light that we can't see and give a very narrow spectrum of light that we can see."

[00:13:23]So, think about what they've done. They have, for the first time in the history of humanity they are now we are now being exposed to light in a very narrow spectrum without anything else. Whatever in the history of of humankind when we light a candle, when we would go outside into the sunlight, when we would have a kerosene lamp we were getting full spectrum.

[00:13:47]In other words, we were never getting blue lights without red lights. Now we're starting to get blue light without red light. So >> So do I change my bulbs?

[00:13:57]>> It's difficult to do that because you can't pick up in these incandescent bulbs, which brings me to I mean at least at least in the United States we have laws now that outlaw the regular selling of incandescent bulbs because of energy efficiency. Oh yeah.

[00:14:11]>> I'm on Google now I've typed in incandescent bulb.

[00:14:14]>> So there's something called a general service lamp, which is what the type of bulbs that you can plug in, but if you decide that you want to get a a bulb that you put into your microwave or a bulb that you would do into a type of chandelier that's a special type of chandelier, those are still available.

[00:14:30]You can still get incandescent bulbs for those.

[00:14:32]>> What about these kinds of bulbs? Is that an incandescent bulb?

[00:14:35]>> That's that is a that is an incandescent bulb.

[00:14:38]Again for these special type of lights, but I'm I'm talking about the light like the like the the good old fashioned A90 I think it's called a light bulb that you just screw in. Those are the 120 watts, those are getting more difficult.

[00:14:51]You it's harder to find. You can't go down to your Home Depot and and find them there. So Glenn Jeffrey and this is this is a preprint that he is he's done. He actually took people with that were working in this environment with LED bulbs. He's actually it's not peer reviewed, it's not published yet, but it's a preprint it's available on the internet, so I'm not speaking out of class.

[00:15:13]And what he did with 22 people is he switched out these LED bulbs and put in incandescent bulbs.

[00:15:23]And there was a there was a 25% improvement in in color differentiation in his study.

[00:15:28]>> What does that mean?

[00:15:29]>> They were able to distinguish colors 25% better than they were when they were exposed to LED LED What I say LED bulbs, these are the bulbs that are high on the blue end.

[00:15:42]Um so why would that be?

[00:15:44]The retina, which is the back of your eye, where in the light is coming in, there's these cones that are tremendously metabolically active.

[00:15:53]They're constantly updating, sending neural signals to the brain.

[00:15:56]And there's it's the it's the one tissue in your body with the most amount of mitochondria. And it's because they have to supply a lot of energy. As somebody gets older, that mitochondria is not producing the same amount of energy. And so the the ability of the energy that those cones have to draw on to do their work is less. And so they're not going to do the job as well.

[00:16:18]If you can perhaps increase the the the amount of output of energy from those mitochondria, you could improve the the the the ability to visually perceive. And and and Glenn Jeffrey's done this study already, where he for just 3 minutes, 670 nanometer light, very similar to that mask, in the eye, only in the morning, improved those people's ability to to to to visualize and actually see.

[00:16:50]>> And what does that mean for the broader picture of our health?

[00:16:52]>> they would be able to distinguish colors better and actually improve their vision.

[00:16:57]That's basically what it means.

[00:16:59]Um and so the question goes back to the first question that you had at the very beginning of the podcast, which is what is the effect of low energy output from the mitochondria?

[00:17:08]Well, it depends on what tissue the mitochondria is in. And so if it's in the eye, then it's going to be a bit visual perception. If it's in the brain, it's dementia. If it's You know, you see you see what I'm saying? So, what we start to see is we start to see that a myriad of different diseases are affected by the sun.

[00:17:28]I I challenge anyone to do this. If you look at a publication in the United States, I've seen it, where they map out the amount of deaths per in a calendar day.

[00:17:40]Cardiac disease, respiratory disease, kidney disease, uh pneumonia, uh all sorts of diseases, infectious diseases, non-infectious diseases.

[00:17:51]You will see a very clear pattern.

[00:17:54]The maximum amount of deaths every year occurs within a month after the shortest day of the year.

[00:18:01]So, we're talking December, January.

[00:18:05]We see the most amount of influenza deaths at that time. We see the most amount of cardiac deaths at that time.

[00:18:12]We see the most amount of kidney deaths at that time.

[00:18:16]So, you might ask, "Well, that that's because uh that's because people get together at Christmas time, and they spread the germs around more, and we have Thanksgiving in late November here in the United States, and and and and that's what's going on."

[00:18:29]The problem is is if you look at Australia, which is on the other end. So, when is their longest day of the year?

[00:18:36]Their longest day of the year is in December.

[00:18:40]And that's when they have the least amount of deaths, despite the fact that they're all getting together for Christmas in December. So, that doesn't fly.

[00:18:47]It's exactly the opposite. The most amount of deaths occur in Australia, in the Southern Hemisphere, in June to July. That's their winter.

[00:18:57]And so, what you see is deaths are correlated to the length of the day.

[00:19:03]This is the reason why whenever they have to whenever they show you deaths in the year, they always have to seasonally adjust it.

[00:19:10]>> And the length of the day is a proxy for the amount of sunlight.

[00:19:13]>> Absolutely. You're much more You're much more likely to get sunlight on the longest day of the year than the shortest day of the year, especially when And and this is well known. There There are some months, especially in people who are doing shift work, like 7:00 a.m. to 7:00 p.m., there's literally like December and January you will not see the sun because you are going off to work before the sun gets up and you're you're coming home after the sun is long set.

[00:19:38]So, you're not You're not able to see the sun. And so, you could go literally weeks without seeing the sun at all.

[00:19:45]>> Is there an optimal time of day to get sunlight?

[00:19:48]>> Yes. So, optimal time of day to get sunlight would be for those that are concerned about getting damage from ultraviolet radiation, as we talked about, when the sun is low in the sky, that's going to be beneficial because the ultraviolet cannot penetrate obliquely through the atmosphere as well as long-wavelength radiation. So, when the sun is coming up >> So, in the mornings?

[00:20:13]>> In the mornings and when the sun is going down in the evenings. That's going to be the time where you're going to get proportionally more infrared light and the least amount of ultraviolet light.

[00:20:22]Now, when the sun is directly overhead at noon, you're going to be getting the most amount of infrared light at that time, but you're also going to be getting a lot of ultraviolet radiation.

[00:20:30]And so, if you're not someone that's gone out into the sun a lot, you may want to avoid this period of time or, as we talked about, put on a broad-brimmed hat, put on clothes. I mean, more clothes because, as we said, ultraviolet light does not penetrate through clothes very well.

[00:20:48]But, infrared light can.