Secrets of LIGHT – Brain Health, Inflammation, Fat loss and More with Dr. Dan Pardi

Content By: Ari Whitten

In this episode, I am speaking with Dan Pardi, Ph.D.—the CEO of humanOS and the host of humanOS Radio. His research investigates how lifestyle factors such as sleep, exercise, and diet, influence cognitive functioning. We will talk about the secrets of light and how it affects brain health, inflammation, body composition, and much more.

In this podcast, Dr. Pardi will cover:

  • The #1book for fat loss. I bet you can’t guess what it is!
  • The shocking truth about how light affects how fat or lean you are.
  • Understanding exactly how light impacts your health.
  • What exactly UV light does to your body and the absolute best ways to stop it from causing damage.  
  • What it means to be light deficient and what happens to your body when you don’t get enough light.
  • The importance of understanding the different wavelengths of light. They each affect your body differently!
  • The vitamin you can’t go without if you want to protect your skin.

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Secrets of Light Brain Health, Inflammation, Fat Loss, and More with Dr. Dan Pardi - Transcript

Ari Whitten: Hey, everyone. Welcome back to the Energy Blueprint Podcast. I’m your host, Ari Whitten. Today I have with me one of my personal friends, one of my favorite health experts, who I’ve had on the show already, who’s one of my favorite podcast guest, his name is Dr. Dan Pardi. Dr. Dan Pardi, now you recently completed your Ph.D. He’s the CEO of humanOS and the host of humanOS radio. He’s a researcher at Stanford University, and his specialties include building systems for health, behavior optimization, and habit building. Welcome to the show, for number two, Dr. Dan.

Dr. Dan Pardi: Second-time appearance. It’s really good to be back. Thank you.

Ari Whitten:  Yes, you were invited back, which means–

Dr. Dan Pardi:  I must have blown it the first time, you’re giving me a second chance.

Ari Whitten:  Yes, we’re doing a redo because your first one was so bad. Tell me a little bit about your background, what’s your PhD and what kind of research have you been involved in?

Dr. Dan Pardi:  I basically did two PhDs. I don’t know if I should be proud of that or ashamed of it, but the first part was all on the molecule GHB or gamma-Hydroxybutyric. Years ago, I started to do work in that field, when I was working for a pharmaceutical company called Orphan Medical. Orphan Medical was working with orphan diseases and orphan diseases has a population of under 200,000 people. They were not actually getting large drug manufacturers to work on compounds for their conditions, and so the FDA created some regulations that then incentivized companies to say, “Hey, we’ll actually limit your cost of development so that you can help to address these people with these needs.”

I thought that was a great mission and that’s when I got into sleep. That was the compound that we had and as I– I knew nothing about either, when I started, but I became very interested in both sleep and this compound and developed my own questions, did writing, wrote a review paper of that, was well received and got a lot of citations. The mechanism of it is just really, really interesting. It’s unlike really any other drug that you think of from a pharmaceutical. GHB is producing all cells of our body, and if you take super physiological doses, it can have a variety of effects ranging from positive feelings that people would take as a drug of abuse and there’s now been more scientific investigation into that, which is cool.

Ari Whitten:  It makes you euphoric, right?

Dr. Dan Pardi:  Yes, it has a euphoric feeling. It actually has pro-social, pro-sexual effects. Oliver Basha of Switzerland has now done some definitive work in that area, series of five or six studies that’s looked specifically into how people perceive others, and it just puts you in a very warm happy and even actually feeling sexual state. He noticed that showing people neutral images was more arousing. It was equal, it was as a rousing as showing people that were not affected by the compound, didn’t have it in their system. They were as turned on if they were watching something that was highly arousing. That’s new and that people, of course–

Ari Whitten:  Or watching the garbage men come by their street, picking up garbage gets them super horny, that sort of thing?

Dr. Dan Pardi:  Yes, exactly. This drug is just sort of personality because they’ve been considered the date rape drug. Although that was an unfair characterization, it can be used in that regard no doubt, but any drug that has central nervous system depression effects can be used in that way, so there’s actually some–

Ari Whitten:  Sorry, I was just going to say, I think there’s also a time, maybe back in the ’90s, when a lot of bodybuilders were using it because I think it’s like a growth hormone to [unintelligible].

Dr. Dan Pardi:  That’s absolutely right. It does directly stimulate growth hormone. They thought for a while that it was stimulating growth hormone because it elicits slow-wave sleep. Unlike most other sleep medications which will put you to sleep, but suppress slow-wave sleep, this will cause very robust increases in slow-wave sleep particularly in certain populations where it’s been tested. It increases slow-wave sleep in all populations that have been tested, even people that don’t have a specific condition. Anyhow, we release a lot of growth hormone during that stage of sleep across the 24-hour period, that’s when you have the highest release of growth hormone. It’s paired, the release of growth hormone is paired with that physiological state.

Further work by some Italians then showed actually, you don’t need to be in that state of slow-wave sleep in order for GHB to elicit growth hormone release. Bodybuilders got word of that and then started to take it every couple of hours, and it made them very lean, but it also can elicit at that point with really serious withdrawal symptoms that have actually killed people. It has a downside and it has some serious consequences, but that’s of course, really abusing the drug. Narcoleptics take it and it helps them have much greater wakefulness the next day, you think of narcolepsy, you think of sleepiness. It also suppresses some of the other symptoms that actually correlate strongly with the intense sleepiness that they have, something called cataplexy. It had fairly miraculous properties for that population. That’s what I started to research, and that’s what I did a lot of my writing on.

Ari Whitten:  That was Ph.D. number one?

Dr. Dan Pardi:  Yes. If I were to continue with that line, then I think that there’s real potential for that medication to help with Alzheimer’s disease.

Ari Whitten:  Interesting. I know it’s used, it’s like, it doesn’t go by GHB, but it goes by another name and it’s used as a pharmaceutical for narcolepsy right now. I think, there were some changes maybe a few years ago if I’m remembering correctly, where it became a scheduled drug and very tightly regulated. I think it’s also really expensive as a pharmaceutical, and I don’t know the details around that, but that’s what’s popping in my head right now.

Dr. Dan Pardi:  That’s absolutely right, Ari. Part of, at the time when it was being investigated for clinical trials for approval by the FDA for narcolepsy, they were afraid that releasing this compound to the world was going to create an oxy cotton-like situation, where they were releasing a compound that was going to help some people but it was going to be widely abused. They didn’t want that. It has one of the only bifurcated scheduling of any drugs which means that if you prescribe it, if a doctor prescribes it for narcolepsy or actually they can prescribe it off label too for anything, then it is scheduled through medication, but if it is diverted in any way, by a doctor or by a patient, then it has schedule on characteristics like-

Ari Whitten:  Interesting.

Dr. Dan Pardi:  – cocaine or anything else. Actually, I think, cocaine might be even schedule too because it does have therapeutic usage. You find cocaine on crash carts. Anyway, so if I were to continue that work, it would be in Alzheimer’s disease because we know that it’s the lack of slow-wave sleep that seems to be possibly causal to the accumulation of the path and amount of characteristics of Alzheimer’s disease, which is the aggregation of beta-amyloid and also, neurofibrillary tangles. So not only does slow-wave sleep help to reduce that disease burden, but it also will elicit [unintelligible] which is a brain protein degrading enzyme, so it actually helps to break down to the beta-amyloid.

Anyway, it does a lot of stuff. That’s what I would do if I was continuing with it. Then the second Ph.D. basically, or the second part of my thesis was really looking at ecologically relevant amounts of sleep loss, and it’s, how does that show up? How does that affect which we can all experience, just missing a couple of hours here and there? How does that affect eating behavior and could that be then contributing to the obesity epidemic? That’s a really interesting line of work, had a couple of papers there.

Ari Whitten:  I will say also, I’m familiar with your work going back all the way to 2013, because my first book, Forever Fat Loss, I drew from some of your work, around your research in sleep and really explaining. You’d written several articles explaining some of the mechanisms linking circadian rhythm and sleep and metabolic regulation of body fat. That was your work and the work of Stephen Guyenet was really instrumental in furthering my own understanding of that topic.

Dr. Dan Pardi:  We’ve had a very complementary relationship. Stephen is an absolute assassin in that field. He really reads research more carefully than just about anybody I know. He has a very strong skill in seeing what the research really says and because he’s so invested in it, and has been for so long when he covers any subject in the area, he covers it very thoroughly and he’s accumulated, he’s crystallized an incredible degree of knowledge and understanding. If you haven’t read the book, The Hungry Brain, which is his book, I recommend you do so. It’s technical. It wasn’t going to ever be the most popular book on weight loss that’s out there. It is probably the best book on weight loss that’s out there.

Ari Whitten:  I agree. I will also say I’ve had him on the podcast, where we’ve covered a lot of the information in that book where I– Stephen is very much an academic and speaks very much the language of science. I think he’s really good at communicating to other scientists. I would just interrupt every now and then and just be like, “Let me just translate that for the average person who maybe didn’t understand what the hell you just said. I think for everybody listening who’s interested and the reasons that the factors that drive obesity and fat gain and lose fat, I just want to emphasize Dan’s recommendation for that book and also listen to the podcast that I did with Dr. Stephen Guyenet as well.

Dr. Dan Pardi:  Let me modify what I said. I said the best book. Actually, you’re absolutely right. The best book for an individual might be a different book that has ideas that are in parallel with his writing. I would say his book summarizes the entire field really well, and it’s mostly suited for somebody that has a higher-level desire to understand some of the intricacies of the mechanisms. But it’s also still– A lot of people could get through it with the right amount of interest than stick-to-it-iveness, but, yes, that’s probably the better way to say it.

How light affects health and energy

Ari Whitten:  Yes. I’m with you. Your expertise centers heavily around sleep and all facets of sleep and you’ve also– I think unlike maybe a lot of people with a similar background you’ve connected the dots with sleep, with some of the other factors, nutrition, lifestyle, environmental level factors rather than just purely this biomedical research paradigm of like, “Let’s identify the biochemical mechanisms and then develop a drug to interrupt galanin or whatever specific biochemical that’s abnormal and people with poor sleep.” You’ve zoomed out and brought things back to the big picture which obviously I love. Something that ties very much into sleep which is light, and that’s the focus of this podcast that I want to talk to you about.

We’re going to delve into light more broadly, but I know we were chatting before this podcast and what we don’t want to do here is rehash a lot of the common knowledge that’s already out there. People are starting to learn more and more about circadian rhythm and that’s becoming more prevalent and more talked about. People already know about the vitamin D story. Those are the two aspects of light and how light affects human health that are at least a little known, but even better there’s way more to the story than most people are aware of. I want you to paint the picture of light and human health more broadly and tell us what are these bioactive wavelengths of light? What’s the big picture of light and human health? How is light affecting us?

Dr. Dan Pardi:  Yes. I’d love to. In fact, I’ll even take one step further back to say thank you for recognizing what my efforts are really trying to do. I feel that scientific journalism is something that is underappreciated in our society, that all institutions are trying to create more and more researchers. There’s not enough dollars for that. There’s a lot of talented young researchers who would know science well, who’ve gotten a good education in that, and yet we need more people that are looking across a subject with some expertise.

Then helping that information you could say it trickle down to all different– Into whether it’s interventions that are being created by companies, all the way down to the person who is just trying to take care of themselves in today’s world. I will probably no longer be an expert in anything ever again, and that I can see that as a strong possibility. I was an expert at GHP at one point and I was completely dedicated to that literature. Now my goal is actually just to look at what are all the factors that are involved in human health and not only that, but then what can we do about it? That’s why I think the story of light is so interesting because it’s– Yes.

Ari Whitten:  I hate to do this, but just something you said just jumped out to me, out at. You said I won’t be an expert at something again. I just want to translate that and what I think you mean, which maybe not everybody listening picked up on, within the scientific community nowadays as of 2019 and really the last couple of decades, few decades, there’s more and more hyper-specialization. To be an expert in something means you need to focus on some very, very narrow sliver of the overall pie to the nth degree and those are the true experts in that field.

There’s a saying that just you reminded me as you were talking, as you said that health experts or I think it’s like doctors know more and more about less and less until they get to the point where they know absolutely everything about nothing. It’s obviously hyperbole, but the idea is this trend of hyper-specialization, and I really agree with that statement to a large degree. This trend of hyper-specialization has created a million fragmented parts of the health puzzle, and you have a million different health experts on little slivers of the overall pie and way too few people who understand how all the pieces of the pie fit together.

Dr. Dan Pardi:  That is exactly right. That is exactly true to my perception. I have seen that. I’ve felt it and I like to stress test that idea. Whenever I come up with a thought or an idea about how something is, I try to look at all the counter arguments that would make that idea not true. I gave a talk a couple of weeks ago and not to get off topic, but it was really on the state of health and our healthcare system. We can rail against the healthcare system for failing but it’s basically– It’s an incomplete system, and it has to do with the fact that it is completely not attending to the full definition of what health really is.

Now if we were to successfully raise a healthy society we would probably be spending 50% of our time in the school age training people for how to live well in a world that is rich with persuasive technology, that is completely embedded into the work and culture of modern life. Not only do you now have to live healthfully with technology that might be pushing you into patterns that we know are not healthy, you also need to learn how to harness tools that are working on your behalf, to help you amplify your efforts to do well. Podcasts are a really great example of that. There’s other tools too, but 10 years from now things will be different.

Mostly we need to not just train specific information, we need to train the capacity to adopt to change. A changing environment, changing the information base and then changing you. Then you also have to be able to work with uncertainty, and know-how to just aim what you’re aiming for and basically not give up all the foundational things when you’re trying something new. So, you’re not just trend topping. There’s lots of ideas there, but that is I’d say the thesis. When I say you’re not going to be an expert in any one thing, my pursuit is to be an expert at tying it together and helping people benefit from, or the farthest our understanding is and actually how that affects their life and how they live, and that’s the goal.

Ari Whitten:  I’ll just emphasize that I agree that is the right goal and that’s my goal as well.

Dr. Dan Pardi:  Yes. Cheers. It’s going to be on this crusade with you.

Ari Whitten:  Also, I veered us off track there but let’s get back to light. Big picture over you, light and human health. What is this story look like? There’s 30,000 flip view.

Dr. Dan Pardi:  The story looks like this. Sun is bad for you. That’s what it looks like.

Ari Whitten:  Melanoma, you’re dead. Therefore stay out of the sun at all costs.

Dr. Dan Pardi:  That would be an exercise or like an orthopedic surgeon saying only seeing all of the fractures and the problems, the orthopedic problems that come in from people that are training and doing exercise whatever and saying, “You know what, we really shouldn’t exercise.” It’s terrible.

Ari Whitten:  We shouldn’t use our hands at all.

Dr. Dan Pardi:  Yes, exactly. We just need to immerse ourselves and then grab some glass jar with– Barely protected in the outside world. That I think is a consequence of hyper-specialization, is that you are seeing a lot of the problems coming in because as a doctor, there’s the other part of how our healthcare system work. It acts when there is a crisis. Somebody, “Oh, what’s this thing on my skin? Let me go get it checked out.” I think with the best of intentions the goal is to reduce the risk of having those problems occur as much as possible. For no bad intentions from anybody in the medical field, but I do think it is a consequence of a system that has some pathology involved and its execution.

Ari Whitten:  That’s exactly what we’re talking about, the hyper-specialization. If you only see skin and you don’t understand how to connect it with everything else you can see, “Oh, there’s increased rates of melanoma or skin damage” and so you conclude you got to stay out of the sun, and yet simultaneously there’s this massive body of literature showing that sun exposure is protective against so many other diseases and even many other types of cancer.

Dr. Dan Pardi:  Right. Let me just say now, like this idea of be a harbinger of the bigger picture here, which is that we are exquisitely sensitive to the natural world around us. Light is a great illustration of this. We must avoid the silver bullet thinking of, “This has been the thing that is explaining all of the issues.” It could explain some, for sure but use it as, “What else might be affecting my health and ways?” Sunshine is– I grew up in a world where you want to try to stay out of the sun as much as possible, SPF 70 wear clothing as much as possible, just stay out of the sun.

That I felt that message became increasingly firm throughout from my young childhood into my young adulthood of maybe 20, 30 years old. Yes, and that I think, and I don’t know if that is a completely fair characterization of how every dermatologist thinks, but I do think it is representative of how the messages that you tend to get from the broader dermatological field.

Ari Whitten:  You’re very nuanced and cautious in your use of language, which is very much the scientific academic style, and I appreciate it. I wish you wouldn’t mince words, because I know what you’re actually saying, but you’re very cautious not to offend anybody in the process. Probably smart.

Dr. Dan Pardi:  Well, it’s actually representative of how I feel. I do think that– I wouldn’t want to impute my opinion about how somebody else thinks, because I’ve not done a survey to say, “All right, what do dermatologists really think?” This is what I think they think, but it would be cool to actually do a survey, because I’ll tell you this, and I bet this is true for you too, that you have been exposed to different types of doctors. Ones that don’t see outside of the guidelines they’re implementing, and ones that feel completely constrained and frustrated by that rigidity. I know, the doctors that I’ve gone to, I mean, they have to work, they have only a certain amount of time to see their patients, they have to work within the system.

I think that that is also fair too, there are different types of people. The other ones are like, “Hey, this is the evidence base, everything else just doesn’t have a strong evidence base. Let’s go with that.” That is how I feel about this. Anyway, the next part of the story I would say is, I gave a Ted Talk just about a year ago. In fact, it might be a year ago. Gosh, what’s the date? The 19th. I think I gave it on the 17th last year. I hadn’t thought about that till this second. That was a really fun experience. It’s a 12-minute talk and it’s called, let’s see. I’m not sure, I can’t remember the title. [laughs]

Ari Whitten:  You can look it up, but watched it right after it came out.

Dr. Dan Pardi:  Oh, cool. I’ve watched it too. How much light do we need? Something like that.

Ari Whitten:  You did it. You not only watched it, but you were the one on stage doing it.

Dr. Dan Pardi:  Yes, man. Boy, weaving together a story like that and memorizing it, had a lot of– It was a fun process, but not an easy one.

Ari Whitten:  How to optimize light for health.

Dr. Dan Pardi:  There you go. That’s a good title. [laughs]

Ari Whitten:  There’s a good title.

Dr. Dan Pardi:  Yes, and that, I think actually is a better way to think about the subject of light, that there are risks involved. It’s not necessarily linear, live outside. We might end up with a situation similar to zero drop shoes where a lot of people haven’t grown up with that, and that we all of a sudden adopt it, you could actually develop some issues as well. Anyway, that subject, the Ted Talk had this cadence to it. I gave an analogy, this metaphor in the beginning of gravity, and that there are really serious consequences when we go into space and live there for a little while.

We know that astronauts have reactivation, blatant variances, loss of muscle mass and bone mass, so much so that if they go up for just a month, they’ll come back down and have decreased bone mineral density for five years. Now, we don’t think of gravity as something that is part of our health, but it is. If we were able to then alter our terrestrial gravity relationship, we would then need to figure out ways to get enough gravity in our day, that was a line.

Sunlight and skin and how much you should get!

Ari Whitten:  If we were all living in offices and structures that were gravity-free environments, or like minimal gravity environments and then there were man-made sources of gravity that only gave you part of the gravity spectrum.

Dr. Dan Pardi:  Yes, totally. I said we would use that technology. Imagine you could put on a suit and you felt lighter, and you could jump like LeBron James. You would totally want to feel that and live with a modified relationship of gravity, but there could be consequences too, and that was that analogy too, was saying, “Oh, well, I’m going to talk about light today. Let’s now start looking at hunter-gatherer patterns.” We don’t know, we can’t say that all-natural living communities had the exact same light exposure, but some work that has been done is that there’s a couple of groups we looked at, they woke up before the sun.

They get outside they had their peak light exposure between 9:00 and 12:00, between when they woke up actually to about 12:00, but the sun became stronger at 9:00 AM. Then they would seek shade to get out of the heat of the day and rest and relax. That was probably part energy conservation as well, lose more hydration if you’re out there working.

Ari Whitten:  Especially in an equatorial environment.

Dr. Dan Pardi:  Yes, exactly. We basically humans had that relationship with light for millennia, all through human evolution, which really includes pre-human evolution because we didn’t just start evolving right when Homo sapiens became identified and present. There was this natural relationship with a light-dark cycle as this earth would rotate on its axis, and there was also seasonality depending on of course, what latitude you lived at. Then, of course, we had the great migrations and people moved away from equatorial settings and into higher latitudes, adaptations were made over time. Whenever we’re exposed to novelty, we don’t do very well at first and there are consequences to that.

Basically, that is the relationship that humans had with light in our distant past. In 1879, Thomas Edison patented the incandescent light bulb, and that technology spread very rapidly over the next 100 years where it went from an idea and a very cool concept or tech to a lot of people having it in their homes. That type of light is not very strong, and it has the tone of sunshine or rather, excuse me, sunsets and dawn, so dusk and dawn. There are problems with that lighting and that it’s very energy costly. We’ve tried to now come up with new light. Then that new light is, first we had compact fluorescents. They maybe were more efficient, but they gave people headaches, and they’re terrible to look at.

Like you said, they’re only representing a certain spectrum of light so it’s an unnatural signal. Then in 1982, the Japanese invented light-emitting diodes or LEDs, and that had a very rapid change because they’re very powerful. They’re more energy-efficient, you can dim them, they can be very bright, you can now even change the color. We have them in our screens. From 1992 until now, that technology has been spreading rapidly as it’s been incentivized. Let’s replace our old artificial lights with these new ones. That’s also really changed how humans live. Most people spend 90% of their time indoors. That’s from the Environmental Protection Agency.

It’s completely changed how humans have lived. Because of that, we are now getting much less sunshine overall and if we do, it’s more, we’re fully clothed. Typically, we’re trying to stay out of it as much as possible. With that backdrop, I’ll spend less time on this now. I talked about a variety of consequences that occur from brain performance issues to mood issues and depression. This is both not getting enough sunlight and also getting too much after dark or even when you’re sleeping. So, you have to consider the 24-hour period. Then the last part was saying, well, what can we do about it? How do we mimic or emulate a natural lighting environment?

When I say the best type of light that you can get at any time of day is the light that’s outside, and how do we replicate that from our indoor spaces so we can do better in the modern life? Following on from that, I really wanted to dive more deeply into the benefits of sunshine because they’re clear. We know that 70% of the United States and over a billion people worldwide have low vitamin D status. Can you successfully mitigate all of those issues of lack of sunshine by taking vitamin D pills and upping, increasing your levels? No, I don’t think so. We also see things like blood pressure changes.

We can talk about some of those consequences, but let’s talk about light perhaps first. If you think about all the radiation that is coming from the sun, there are different types, and we won’t go into all of them. But you’ve got the visible spectrum, which is 400 to 800 nanometers. That’s the wavelength of light that we can see. If from the 400 side, that’s going to be really dark blue, all the way up to 800, which is very vibrant, red rich, very rich red. Beyond that, you’ve got infrared spectrum, both near mid and far. The wavelength essentially keeps getting longer and longer as you go out in that direction.

If you go in the other direction towards the blue, and you keep going past the visible light spectrum on that side, the wavelengths get shorter and shorter and shorter, and you enter first into the ultraviolet radiation spectrum.

In that we have three different bands that you can consider and those include you UV, A, B, and C. We mostly are thinking about the health benefits or the health implications, I should say of UVAB. Because most of the UVC is blocked by the ozone layer. Now that would have been more of a concern when the ozone layer was depleting, but we’ve made some good strides there so that’s good. But then with UVB, that’s going to be a wavelength of around 280 to 350 nanometers. About 5% of ultraviolet radiation that reaches the Earth’s surface is UVB. The preponderance of UV light ultraviolet radiation that is reaching us is UVA. That’s a wavelength that is 315 to 400 nanometers. You can almost think of it like really dark blue light. [laughs] It doesn’t have color to it, you don’t see it, but that’s a way to conceptualize it.

Ari Whitten:  We can see a small part of the UV spectrum, right? Because there are UV lights that people use for sterilizing, and we can see just maybe a very small piece of the UV spectrum that overlaps into what’s visible for the human eye? Is that it? That’s my understanding. I’ve always assumed that.

Dr. Dan Pardi:  I think that that’s true. For both sides of that visible light spectrum where same with infrared, at the very end, at the very upper end there between red and infrared, then you can see probably a little bit of that too. When we think about the characteristics of UVA, that’s the stuff again that 95% of the UV that you’re getting exposed to is that. Now how much you’re getting exposed to depends on a lot of different factors. Is it winter out? Are you in a colder climate? Is it early morning or later afternoon? What about if you’re getting the exposure of light but through glass?

Actually, UVA does go through glass, but UVB doesn’t. There are some health risks, it can induce pro-inflammatory cytokines in the skin and it can degrade vitamin D. I’m looking forward to talking with you. I won’t go on a tangent about that now but just this relationship between light and vitamin D, not just as a stimulator.

Ari Whitten:  Real quick. The pro-inflammatory cytokines, I think can sound scary to people. I think it’s also important to understand, to integrate this with an understanding of [unintelligible] and the fact that for example, exercise, physical exercise can also create a transient increase in pro-inflammatory cytokines. Yet it’s still perfectly helpful.

Dr. Dan Pardi:  100%. Pro-inflammatory cytokines are signaling molecules in the body. Rudimentarily, we just talked about inflammatory cytokines as good cholesterol, bad cholesterol. It’s really about the balance. To your point, that tends to be a horror medic signal that then elicits favorable responses in the body. It’s not automatically bad, but it is a source of, you could say risk under certain conditions. Other things that matter too, your altitude if you’ve ever gone skiing, and it’s cold outside that you get terribly burned. You come back, you look like a lobster because at altitude, you’re getting more exposure.

Then you can also get quite a bit if you can look at a UV index, which is a measurement of the UV are getting exposed to. Under certain conditions, some people will get burned when it’s cloudy out because the UV index remains high. People think, well, the sun is not out, and therefore I’m not getting as much exposure to it. If it’s a warmer day, you could end up getting burned that way too. Then of course, surface type. If you’re by the water, you could get burned because the UV is actually getting reflected against you. Those are some factors when we think about light, what it is and how what your exposure is to it.

Then if you think more about from an individual level, things that are going to infect your exposure have to do with genetics. Do you have naturally dark skin? By the way, an interesting question for me is, we’re so mixed now. My mom is so white. [laughs] She’s polish and Irish. My dad is Maltese. He had dark skin and I’m somewhere in the middle. I turn red a bit, just like my dad did when I get tanned. I’m still wondering, I’m like, was that a sign? Is that just how we tan or am I getting some good benefits from my genetics and also have some risks there too? I don’t know. Then things like your age, if you like anything, the more damage you’ve occurred in your life, then the more risk, the more vulnerable you are to stressors.

You might not be able to respond in a healthful way, were the same degree of exposure to sun earlier in your life might have not been bad, but now it could be harmful. Because with age really thinking also about exposure history. Did you get a lot of burns when you were young? Then how tan are you right now? Tan is protective, right? We mostly tan from the UVB spectrum. I think walking around with a light tan all year long is a good idea. That’s another idea. Then of course, your clothing. This is what I was going to say earlier about vitamin D, is that your vitamin D status if you think about a modern person’s relationship, you might get very little light exposure, sunlight exposure throughout the year.

Then you go on vacation and then you get outside and you get a lot. We know that a lot of people have low vitamin D status. You go outside, you have low vitamin D, you don’t have much of a tan. Those rays hitting your skin are going to be probably more harmful because you haven’t acclimated to them. Now, of course, I’m not saying not to, but you really want to be very careful, I think of how much sun exposure you get. You don’t want to binge and purge relationship with the sun. You want a nice consistent relationship with the sun and how much you get is still, I think, a question that I am searching for. What is healthy and what is problematic? That’s obviously probably going to be a moveable spectrum and depends on genetics and things like that.

Ari Whitten:  Understanding that you just said it’s a complex topic that you’re still looking for more certainty on?

Dr. Dan Pardi:  Yes.

Ari Whitten:  I will say that my personal interpretation of most common recommendations, is that they’re way underestimating what is normal or probably optimal for most humans. Understanding there is a huge range of probably what’s optimal depending on ancestry and skin type, from everything like maybe optimal for somebody with super pasty skin and U melanin from Irish ancestry or from Scandinavia or something like that. It might be maxing out at 10 to 20 minutes a day of direct sunlight.

I was down in Mexico recently in a tropical environment down there surfing, and a lot of the local Mexican guys who were surfing with and who were taking us out on boats to the surf spots, they just literally hang out all day in the direct super-hot, almost not equatorial, but very intense like tropical sun for six, eight hours a day of direct exposure of sunlight and their skin is completely adapted to it. They don’t wear sunscreen and they don’t get sunburn. I’m just curious what your take is on how you would explain what’s an optimal amount of sun exposure?

Dr. Dan Pardi:  My bias is that the more natural we can live, then the better. I agree with you that once you have been able to make the acclimation to the sun stress exposure then there might not be an amount that is really very harmful to you. But I do also know that a lot of things have changed, not just our relationship with amount of sunshine we get. Our diets have changed and the diet has a big impact too. In fact, if we think about some of the consequences of sun exposure, they are real, you have things like sun damage. We call that erythema or reddening; you can have edema of swelling of the skin. This is again from getting burned. Photoaging, we know the mechanisms there to break down the collagen et cetera. Then there are, of course, the cancers melanoma, lip cancer, keratinocytes. Those are ones that are our concern. Then ocular cataracts, ultraviolet keratitis things like that are also concerns. We know that the ultraviolet radiation can directly damage DNA. How? It can do so in a couple of ways, but primarily by forming what are called protein dimers. What that basically is, is you form molecular lesions between thymine and cytosine basis in DNA, so they stick together when the photon of UV light hits the DNA.

Now, that doesn’t mean that we should totally stay out of the Sun because we have good DNA repair mechanisms that can come by. It can actually fix those protein dimers. It can cleave them it can put things back in safe. The damage effect does occur, and so you have to have good DNA repair mechanisms. That is hearkening to my comment about diet. If other parts of your life happen to not have adequate contributions that then are helping with DNA repair processes, you’re not getting enough sleep.

I just had a podcast with Leo Applebaum talking about the intimate relationship with DNA repair processes and sleep. You have to then consider other factors too that could then put you into a state where the stress stimulus which can be healthy, is now becoming problematic. It’s not directly related just to your sun exposure pattern, it has to do with other things too.

How certain foods can help build up internal skin protection

Ari Whitten:  Yes. This is a good point, and I was hoping you’ll bring this up. Because there’s also a lot of research around like, for example, specific phytochemicals that can build up in our skin cells that help protect the skin cells from UV damage. There is this very direct relationship that is already it’s not speculative it’s built out in the literature. It’s pretty substantially already as far as your consumption of things like astaxanthin, or cacao or various kinds of polyphenols, sulforaphane, things like that. That literally enhance your skin cells ability to take in, to be exposed to that sunlight and not incur lots of DNA damage from it.

Dr. Dan Pardi:  That’s exactly right. Even there’s been some interesting work. There was a paper in the New England Journal of Medicine. I’d love to get him on the podcast actually. Looking at NAD supplementation and how that affected the solar stress radiation response. Broadly phytochemicals there’s something called fern block, which is for this– In heliocare. These are oral sun protecting agents, and do you actually need to go buy those? They just tend to have their vital nutrients that are causing a good effect and some of them have more research than others.

My feeling is that you are probably just having a good vital nutrient-rich diet is good. When I get some exposure, you know what I always do? I go find a rosemary bush and I just will chew on it here and there across the day. Just take some off and eat it, because the rosmarinic acids have also been shown to limit the solar stress. Vitamin D is another factor, so if you have low vitamin D status, then another potential– I’ll say this, another potential thing that one could do, and I don’t know this to be true, it’s speculative, is to take vitamin D. If you know you’re going to get a lot of sun exposure that day, take some vitamin D beforehand.

Ari Whitten:  That’s interesting. Explain that, so the vitamin D itself it’s part of the skin signaling that lets it say, “Hey, we’re used to sun.” Whereas like if you have low vitamin D are you saying that the skin is more sensitive to sun exposure? Because it’s basically saying it’s more likely to just get damaged sooner?

Dr. Dan Pardi:  It in itself is protective, the vitamin D.

Ari Whitten:  Interesting.

Dr. Dan Pardi:  Yes, and it makes sense. When you get more sun exposure, your body produces more vitamin D. A lot of times–

Ari Whitten:  That’s fascinating. I did not know that because everybody thinks of vitamin D is like what it’s doing once it gets in circulation and what it’s doing in the body, but the more obvious thing, maybe just that it has very local effects as far as helping to protect your skin from sun.

Dr. Dan Pardi:  Yes, that’s right. It’s funny, oftentimes by the way, side point, we’ll see that “Oh, this inflammatory marker is off,” and I’m just making up a scenario here to illustrate a point. “Therefore, that’s bad.” What if that was protective? What if that response is actually doing its best to protect the body in important ways? Of course, it might therefore be a signal, but you can, I shall give you a direct illustration of this. That in Alzheimer’s disease, drugs that would break down or prevent the formulation of beta-amyloid cause the worsening of Alzheimer’s symptoms. That indicates that the beta-amyloid is occurring as a protective process and you can monitor it and it’s not a good sign, but preventing it is actually preventing the things that the body’s doing, in its intelligence to try to then limit the consequences of the situation. You can see a lot of different ways.

Ari Whitten:  Yes, and just for people who didn’t quite follow that, we’ve known for a long time that beta-amyloid plaques are implicated in Alzheimer’s pathogenesis, the generation of Alzheimer’s. It was thought all these plaques are causing the Alzheimer’s, and so let’s develop a drug that interrupts and inhibits the plaque formation. What Dan was just saying is that drug actually sped up the development of Alzheimer’s symptoms. It didn’t make things better, it made them worse it accelerated the progression.

One other layer to the story I think that I think is although it’s somewhat speculative, there’s not a whole lot of science yet I think it’s a big player. As far as our skin’s resistance to sun exposure is the full spectrum of light. I think a lot of the research that’s been done showing the harm of UV has been done in vitro, or has been done with isolated UV only light. Only ultraviolet light in isolation.

We know, I’m pretty confident that the research is going to conclusively show that red and near-infrared light maybe also mid and far infrared light counteracts some of that damage. Has anti-inflammatory DNA protective and cell regenerative effects that counteract simultaneously some of these oxidative stress and DNA damage that’s being done by the ultraviolet light. This is why I think the tanning beds are very clearly linked with increased rates of cancer, whereas sun exposure isn’t.

Dr. Dan Pardi:  Yes, I fully agree. We know you’re far more of an expert on red light than I am. That’s the next thing that I would like to shore up in my quest for personal health mastery is this element to really understand light, that aspect of light better. In fact, in the beginning of my talk that I did at the HS this year I said, “Here’s the spectrum of light.” I’m not going to talk about this today, we’re going to talk about other parts, but yes, I do agree with that. I know enough to know that the full spectrum of light that we get from the sun seems to be offering stress-inducing rays and ones that then happen to counterbalance the negative effects of that.

My question is, does timing matter? If you think about how much red light exposure we get across a 24 hour period, what point is it higher? What point is it lower? Some very interesting questions to me about timing. Yes, so but I agree largely that I know I think if we add natural light UV bulbs, where you got more of a full spectrum of light. Hey, you know what we’re not including all of the radiation or the radiation that the sun emits just by including UV visible, and also infrared spectrums. That would be a better start, a better place.

I can actually envision a time when we now had tanning beds in our home and got five or 10 minutes a day, just as a health practice. I would like to see that I think. I think I’d like to see more work on that, but I think that could be a good way to go. Because obviously, not everybody is in a situation where they can get full body sun exposure regularly. Would getting a little bit per day, let’s say 10 minutes in your home be better than the pattern we have now? I think so.

How sunlight may affect cancer

Ari Whitten:  What else is going on here with this light and human health story? There’s this vitamin D aspect we’ve mentioned red and near-infrared to some extent here. There’s different layers of the UV story. Where do you want to take this next? I’m curious also, have you dug into the melanocortin system at all, because there’s some really interesting stuff also that ties back into body fat regulation. Which is one of your seven PhDs that you’ve done.

Dr. Dan Pardi:  I would like to do more. It would be just there. I’m glutton for a punishment. There’s a variety of different subjects, those are some of the elements of sunshine that we should consider because they are real, but as we’re discussing, they might be artificially inflated in that is it the exposure pattern? Is that the type of light used in that particular study? There’s even some evidence that women at higher latitudes– There was a Swedish study, women that were getting sit tanning bed, not even a full spectrum of light, were having better outcomes on a variety of health-related topics.

About another way to think about this is yes, we do have increased risk of melanoma. We see that at least in the pattern that we have now but it’s not linear. It’s not linear in terms of groups of people that get naturally a lot more sunshine. We don’t see people that are living equatorially having skyrocketing levels of melanoma. Then we have to then look at, “Well, how much death does the skin cancers that are probably caused by sun exposure? How does that compare against any sort of anti-cancer effects that sunshine has?” That has been seen.

You can look basically at things like breast cancer, colorectal, which is a very big killer, meaning that it’s very deadly. It’s about 4% of the lifetime risk of getting cancer in your life, is towards colorectal cancer, but it accounts for almost 10% of the deaths. It is particularly deadly. Things like non-Hodgkin’s lymphoma, prostate cancer, you see a decrease in the risk for those cancers when you get more sunshine. Not only that, but you also have a better survival.

If you’re getting more sun, your cancer survival is basically associated with better responses in the patients that have higher cumulative sun exposure or who are diagnosed in the summer or autumn. That to me is a really interesting thread to the story. You might be increasing your cancer melanoma but decreasing your chance for other cancers that are more deadly.

Ari Whitten:  You just reminded me, this book called Embrace the Sun, it’s by a few different guys, Mark B Sorenson, William B Grant. I think those are the two main authors. They did a really great job compiling a lot of research, and there’s one specific chapter where they compile the statistics on basically how many people die in the US every year from diseases associated with sun overexposure versus how many people die from diseases associated with sun deficiency.

The statistics I’m going to get– The exact number is wrong, but it’s literally something like 5,000 people a year die from sun overexposure related conditions and something like 250,000 die a year from diseases associated with sun deficiency. When you frame it that way, it just makes it look all the more silly when somebody who’s hyper-specialized in one specific field, like dermatology is saying, just looking at the skin side of the equation and saying you got to avoid the sun, look what it’s doing to your skin.

If you avoid the sun, you’re also dramatically increasing your risk of dying from 30 other diseases.

Dr. Dan Pardi:  It is the consequence of that hyperspecialization. What are all the other different factors? You could argue, and we don’t have to go into this now, but others have argued that obesity is the greatest modern health risk of our day. The reason why is because of, if you think of obesity not as a level of body fatness on the body, but rather as a metabolic state that has high association with over 50 to 100 other conditions that lead to premature mortality, you realize that it’s a very big concern beyond the hyperspecialization of just looking at fatness or that itself.

It’s really indicative of a bad metabolic condition, particularly the very high levels. The evidence now for sunshine and weight is pretty cool. I’ve been enamored with finding out more about it. There are multiple threads, and so you mentioned the melanocortin system. What that is, Pro-opiomelanocortin is a peptide that is released in a couple of different places in the body, and those include mostly in the arcuate nucleus of the brain. That is an area that is considered almost like the fat set point.

You have certain neurons that are there that are producing these compounds. A lot of work actually into obesity drugs has tried to target that system directly. We know that individuals that have monogenic mutations of the melanocortin system have excessive obesity. There are 500, 600 pounds. Of course, most obesity is more polygenic, meaning that you have increased risk depending on the complement of genes you have and how they interact with modern environment.

You could be living a similar lifestyle. It’s one way to look at it, living a similar lifestyle but having very different outcomes and somebody else that has a different set of genes. There’s not a perfect depiction of that. Anyway, melanocortin is also released in the skin and it’s released in response to sunshine. That is quite interesting. Some of the cleavage products, this peptide that is produced is then broken down into a couple of different compounds, and those compounds are alpha MSH, which is a compound that has anti-obesity effects, beta-endorphin which we think of– I think if you know that compound you think exercise.

You exercise and you have to release, that good feeling hormones are released, that’s beta-endorphin. Also, adrenocorticotropin, some stress hormones as well. Alpha MSH helps to prevent obesity by basically suppressing appetite, that’s how it works. Exposure to the skin or eye from UVA, in particular, this is the work that’s been done just in UVA, you see a surge in alpha MSH. That’s interesting. That’s one line because part of the problem is that we’re also eating more.

Are we missing a signal by the way that we live, coming from sun that as contributing to an appetite that is deregulated in a manner that would lead to overconsumption in a permissive environment like the one we live in with lots of food choices?

The link between sunlight and body composition

Ari Whitten:  Well, to zoom out now to the big picture level, you talked about the mechanisms there. You could extrapolate that theory and say, “Well, if you don’t have as much of this compound that would be suppressing appetite, maybe that’s contributing to increased hunger that’s driving fat gain. Then you could look at the macro level and say, “Well, do people who get more sun exposure, are they leaner? And do people who get less sun exposure, are they fatter?” We see at that level, it’s true there as well.

Dr. Dan Pardi:  You could see that if a lot of people would avoid sun exposure or if they were overweight and uncomfortable with their bodies, and therefore were then avoiding getting more sun. That would be an unfortunate consequence for avoiding something that could ultimately be helpful. One other area that alpha MSH is produced or Pro-opiomelanocortin, which then, of course, converts into those three different compounds that I mentioned, is also in neurons. That actually illustrates a similar idea that I talked to with Antonio Nunez, who is a professor at Michigan State.

What he did is he took mice and he put him in a dim light environment for a period of time and he found that that constant dim light caused memory forming, hippocampal neurons to basically degrade and shrink. Then the performance on their memory tests was terrible and so we put them back into normal light and the stress of light caused the increase in

Dr. Dan Pardi:  EDNF and also another hormone called orexin which by the way, we talked about narcolepsy a little bit. Orexin is missing in people that have narcolepsy, I point but those compounds are induced by the stress of life and then they have a positive effect on causing plasticity and growth of neurons. Similarly, getting light into your eye also will elicit this appetite suppressant hormone, Pro-opiomelanocortin. Undoubtedly, there’s more effects like that that are occurring. Not only do we not get a lot of light, but we go outside and put glasses on right away.

Ari Whitten:  There’s another layer to this story of light and fat, which is more recently uncovered. I think just like literally maybe a year ago, I want to say there was some groundbreaking research that came out. I can see you nodding so you already know what I’m referring to.

Dr. Dan Pardi:  I know what you referring to.

Ari Whitten:  Can you explain what these other layers of the story of light and fat cells is?

Dr. Dan Pardi:  Blue light baby. This is really one of the coolest studies that I, fortunately, got to speak with Peter Light about it who discovered it. I’ll tell you the story because it’s an interesting one.

Ari Whitten:  Peter Light.

Dr. Dan Pardi:  Yes. Right, he said this is one of the best [crosstalk].

Ari Whitten:  He’s like, “My last name is Light and got to study Light.”

Dr. Dan Pardi:  Yes. He has the light lab in Alberta, Canada.

Ari Whitten:  Is it named after light or is it named after his last name? Did he name it after himself for what he studying? [laughs]

Dr. Dan Pardi:  I think it was after himself because he did not intend to get into this field.

Ari Whitten:  Yes. Interesting.

Dr. Dan Pardi:  Yes. His work was focusing on islet signaling from the pancreas and diabetes. They were developing therapies to try to treat diabetes and other metabolic conditions. His original research idea was basically to look if they could transduce these photo-responsive– There’s a new field called optogenetics. Optogenetics can insert a light-responsive gene into various places throughout the body and then activate it with blue light.

We have a lot of ops and tissues that are throughout the body, of course, they’re in the eye. It’s a cool research technique because you get what they call better temporal resolution, you get better specificity and temporal resolution, which means that you can control the activity of turning on a neuron or turning it off like you’re controlling it and oftentimes pharmacologically you might be turning on several other different neuron systems.

The clenseliness of understanding exactly what neuron systems do what is been augmented through this technique. He was going to look to see if they could transduce photoresponsive receptors genetically into fat tissue, and then use that to then express insulin, which– Wouldn’t that’d be cool. Like you shine a light on your side.

Again, this is more just like they were doing it for research purposes but that was the original idea. They wanted to come up with a negative control. This is the, you always have a placebo. This negative control means that the group that should not be having an effect at all. They expose these control cells to blue light, and they were expecting no response but instead, the light elicited a reproducible small electrical current. They’re like, “What the heck, what is this artifact? Why are these cells that I didn’t transduce this photo responsive gene into, why are they responding to light?”

After they did some deep work in the library, they determined that something called the OPN4 gene codes from that non-opsin and isn’t expressed in white adipose tissue. Interesting. The next part was, they had no idea there was not– Actually, he said to me on the call, he said, “That took a lot of work.” It wasn’t a well-known fact, they had a researcher. Now that they had this idea they’re like, “Wait a minute, so fat tissue has like receptors already in them?”

Okay. Then they contacted some plastic surgeons, and they were able to get by having people sign off and contributing their fat samples, they were able to get human fat tissue, and they ran these light-sensitive currents were basically detected by the fat tissue. They’re like, “Okay, we’re onto something here, what’s going on?”

Now they have an idea like they were doing something completely different, now they have they’ve stumbled upon this mechanism, they were totally not expecting it. Now they wanted to set up an experiment directly to test this. They then try to determine if this was basically like relevant at all. Like, “All right, so they might be having an effect, let’s test it but is there a consequence to that effect that we care about or is it just epiphenomenal.”

They expose fat cells to a range of different wavelengths and finding that the fatty tissues were maximally responsive to blue light. Light somewhere between like 450 and 480 nanometers, that was the light that was causing a reproducible current and in the fat cells.

Now, they figured that it really requires a very bright light source, because only about 1% or 5% of light from the sun is penetrating the skin. If you had let’s say, blue light in your environment, might that be having a bit of an effect? Maybe not. Probably not according to him, it might not be strong enough to then actually penetrate the dermal layers and get to the fat tissue. It probably has to be the big, as he said the big solar radiator in the sky. That’s sort of what they studied. Here’s the light, here is the light type.

Then their next populations were on cells with longer-term exposure to the blue light. They have an idea, now they want to say, “Okay, well, if we put them under exposure repeatedly, what do we see?” They had them exposed for about two to four hours per day for 13 days in a row and then they were looking at the structure and function of the adipocytes. They found that it was physiologically relevant.

After 13 days of exposure, the fat cells were smaller. There were fewer cells that had these really deep lipid droplets. In other words, they weren’t storing as much fat there was like– They weren’t storing as much fat. This is a big deal because smaller fat tissue are thought to basically be less inflammatory and generally associated with better metabolic health in general.

They then looked at things like leptin and adiponectin and glycerol. Now, it doesn’t happen immediately but in this study of 13, 14 days of two to four hours of blue light exposure a day, you saw a significant reduction in a variety of different hormones like leptin, adiponectin, and also higher glycerol release. These cells are now releasing more fatty acids and affecting metabolic state. Wow. They basically said the quote that he used was something like, “We might have just stumbled across a mechanism designed to increase that storage during winter months.” When the tone and intensity of light goes down, that is a signal of human body to then store a little extra subcutaneous adipose tissue so that you have better thermic regulation in a colder climate.

Ari Whitten:  Yes. A couple of things, to comment on that last bit specifically, obviously relevant in the sense that we’re no longer that seasonally attuned in the sense that most of us are living in climate-controlled indoor environments now. We’re not getting those seasonal differences. Maybe, more importantly, most of us are getting little to no sun exposure. We’re not getting this light stimulus on most of our body fat stores where it could even have this effect. Most of us are missing that due to modern-day indoor lives.

The other thing I want to just comment on personally is that this was fascinating, I did not know all the background story leading up to this discovery so that was fascinating to hear the explanation. There’s multiple layers here circadian rhythm, there’s the melanocortin system, and how that affects appetite and there’s this direct effects of blue light on the fat cells.

There’s also research showing the red and near-infrared light can affect fat cell metabolism as well. There’s at least four mechanisms by which light is going to impact on body fat regulation here. It’s fascinating to uncover this because as we can see this story of light is so much deeper than most people think. Most people light is just the opposite of darkness. I turn on a light switch in a room and that’s what light is good for. They don’t realize that the light that they’re getting is directly impacting on their fat cell metabolism and causing electrical currents and impacting on feeding through their eyes impacting on the circadian clock in their brain.

Regulating all these different neurotransmitters and hormones and mitochondrial function and levels of inflammation and vitamin D which regulates over 2000 genes and red and near-infrared light which are directly impacting on growth factors and tissues and modulating inflammation and all these different aspects of how light is affecting our body and that’s not even the whole story. There’s like light impacting on our skin as you said, causing the release of beta-endorphins and maybe serotonin via skin pathway.

I think the big picture here if people are following all these layers to the story is like our body is deeply and profoundly responsive to all these different wavelengths of light. They’re doing all kinds of crazy stuff and activating literally probably a dozen different mechanisms and pathways in our body and influencing the expression of thousands of different genes in our body. Light is a drug, or maybe better-stated light is a nutrient, much like food, and we need different nutrients from food, and that impacts our body in profound ways. I think light is the same. We need different new light nutrients, and those things impact our body and all different profound ways.

Dr. Dan Pardi:  Nitric oxide release another one.

Ari Whitten:  Yes, I was just going to say, is there anyone or two pathways? There’s probably 10 more that you could talk about, but are there one or two more pathways that you think would be relevant to add here?

Dr. Dan Pardi:  Yes, in the Ted Talk, I talked about how blood pressure rates rise linearly as you move away from the equator and how blood pressure tends to be higher in winter months than it is during the summer. Well, it also seems there it could be a plausible mechanism here for body fat regulation as well. How well dietary nitrates can cause a browning of white adipose tissue. What does that mean? Brown fat is really anti-fat. White adipose tissue stores, lipid droplets and can be used for fuel and just for, the–

Ari Whitten:  Insulation.

Dr. Dan Pardi:  Thank you. Thank you so much [laughs].

Ari Whitten:  I could see by the way you were miming it.

Dr. Dan Pardi:  Yes, exactly.

Ari Whitten:  You were doing like a whale or like seal blubber, hand gestures.

Dr. Dan Pardi:  I’m so glad you got that. We would absolutely crush it at that game where you like to draw on the board, and I have to guess the word [laughs]. We see this increased expression of thermogenesis related genes in brown adipose tissue with nitric oxide release. We get more of that when we get exposure to sunshine. Could you have an increased browning? Brown fat is actually considered a newer field because we thought we lost all brown fat by the time we were an adult. That has everything to do with how we’ve been living.

Ari Whitten:  It’s like it’s only in kids and babies, and then adults don’t have this. Then we realized that the reason adults don’t have it is because we’re living in modern climate-controlled insulated environments.

Dr. Dan Pardi:  Yes, exactly. Probably aren’t getting, and by the way, there’s a melatonin connection as well in terms of stimulating brown fat we’re living in less darkness. You have a lot of different connections there for disconnection. I think trying to regulate this in the modern world is hard. I’m really intellectually stimulated by this idea of blue light. Now, we don’t know how sensitive that system is. They were looking at two to four hours a day. Let’s just for argument’s sake that is the amount that we need.

It’s going to be hard. That’s going to be hard to get two to four hours of blue light. That’s particularly, and only, particularly if it’s coming from the sun. If it has to be that strong to penetrate the dermal layers and get into the fat tissue, it’s got to be the sun that’s doing it.

That’s going to be a hard thing to take advantage of even if more evidence builds up that it’s true, but we know more and more people can get outside. What I would say to close– Because gosh, there’s more to talk about, but I’ve got my kids– [laughs]

Ari Whitten:  Yes, I apologize for going a little over. I was going to ask you, and I want to be sensitive to your time here. We’ve covered a lot of theory, a lot of the mechanisms. I would love to wrap up if you could give like your top two or three light related tips, and you don’t have to give big explanations because we’ve already covered that, but if you could give your top two or three strategies to use some of this science around the light to benefit people’s health, what would you say?

Dr. Dan Pardi:  You know, I’ll leave it at one.

Ari Whitten:  Okay. You’ve been that much of a time crunch?


Dr. Dan Pardi:  Well, I want to be able to remember this one. Work to mimic a smart daily light rhythm, day, evening, and night. We have after the Ted talk on Human OS, I created a how-to guide. And in this, I talk about daylight exposure. I talk about evening exposure settings on your phones. A lot of it has to do with circadian rhythm elements, but generally speaking, I do have two recommendations. Generally speaking, try to have your indoor spaces, better reflect what’s going on outside.

There’s different degrees of sophistication, and I’ll give you one example of what I mean. You can get bulbs that can change their tone and intensity either manually, but they can be changed over the day, or secondarily, you could just have a different set of lamps that you use in the evening that then you turn off your day lamps and you put on your night lamps, that’s a good way to go.

There’s nothing better than just getting outside. The second recommendation is this. We do have that binge and purge type of relationship with the sun. Take it slowly acclimate to this over time. Don’t get burned. We do think that there’s a lot of evidence around skin cancer and skin problems. Photoaging is this binge and purge relationship, that might be the thing to avoid. Take it very slowly. Almost like I say, with cold showers.

If the idea of that is so detestable to you that you just can’t do it, take a warm shower, then make it cool, do what your body can handle, and then acclimate over a period of time. It takes some discipline, takes, you’re going to get a lot more benefit, from sun exposure of doing it regularly, consistently over long periods of time than you are going to get a tan for a weekend, and then you’re back where you were. Be conservative but be consistent, and then you can level up to the point where maybe like those people living in that place in Mexico where you worried you’re outside all day and they’re healthy people.

Ari Whitten:  Beautiful. Dan, this has been awesome. I’ve absolutely loved this conversation. One of my favorite topics with one of my favorite people, I say this every time we talk, but I need to have you on again. For everybody listening, Dan has a brand called Human OS, Human Operating System. There’s an amazing podcast. There’s a great website, tons of great articles that he gives out for free. There’s a great program that is ridiculously cheap. I think it’s 10 bucks a month or 15 bucks a month.

Dr. Dan Pardi:  10 bucks a month.

Ari Whitten:  Access to amazing knowledge in there. I highly recommend it to everybody. The podcast is excellent too. He brings on lots of world-class researchers, and they talk about very niche topics as you said, like, for example, DNA repair and sleep, and you’ve brought on a couple, mitochondrial experts, Michael Risto and a few others. I listened to it myself. I love it, as it’s one of few health podcasts other than this one that I recommend to people. Of course, yes, Dan, really a pleasure. Then if you want to give a little pitch on where people can follow you and what you would recommend.

Dr. Dan Pardi:  Yes, we’re pretty active on Twitter. It’s more scientific there, the conversations on the podcast I love them, and that’s not about me, it’s about the guests. I go directly to researchers. I think there’s a lot of different types of good conversations, but I felt that was missing often. I go speak with a researcher, and I talk to them about their latest study or their understanding of the field.

At this moment in time, we launched a podcast yesterday with Professor Pankaj Kapahi, from the Buck Institute, and we talked all about AGEs or Advanced Glycation End Products. The podcast is the official podcast of the Sleep Research Society and The Canadian Sleep Society, but we cover aging, mind everything related to the body and how to get it to be its healthiest, and it’s a lot of fun.

Then on Human OS, funny enough, our courses are a little bit different. They are actually not as detailed, and they’re really designed to give somebody a framework understanding of the subject. They’re 20 to 30 minutes, and we want you walking away from taking one of these micro-courses and be like, “I understand that subject much better now and we really want to help people pursue fluency, which means you know a subject well enough where it can direct your actions.

Then we pair that with how-to guides and sometimes other tools, whether it’s a diet, let’s share a bunch of recipes and we’ve got workouts, and you can track yourself. It’s an ecosystem of support all the help amplifed the efforts that you are putting in to make those more effective and efficient over time. That’s what we do, and it’s such an honor to always come on here. I love our discussions.

Ari Whitten:  Yes, me too. Real quick just to make sure people know where to go. It’s, is it human? I forget. It is or dot?

Dr. Dan Pardi:  Dot me. Thank you.

Ari Whitten:  It’s all about me.

Dr. Dan Pardi:  It’s all about me [laughs]. Go there. You can check it out, and then you can find the blog there too and links to Twitter and all that.

Ari Whitten:  Awesome. My friend. Well, thank you again so much. I know you got to run to do your thing with your kid. It’s time for my evening adventure with my son as well. Have a great one I look forward to talking to you again very soon.

Dr. Dan Pardi:  Yes, likewise. All right. Have a great night.

Ari Whitten:  You too.

Secrets of Light Brain Health, Inflammation, Fat Loss, and More with Dr. Dan Pardi - Show Notes

How light affects health and energy (10:58)
Sunlight and skin and how much you should get! (25:03)
How certain foods can help build up internal skin protection (41:48)
How sunlight may affect cancer  (49:55)
The link between sunlight and body composition (58:24)


Listen to the podcast with Dr. Stephan Guyenet on Carbs, fat, insulin, and fat loss

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