Future of Sunscreen and Final Recommendations

Welcome to Everyday Wellness Podcast. I'm your host, nurse practitioner, Cynthia Thurlow. This podcast is designed to educate, empower and inspire you to achieve your health and wellness goals. My goal and intent is to provide you with the best content and conversations from leaders in the health and wellness industry each week and impact over a million lives Today I had the honor of connecting with Rowan Jacobson He writes about science and nature in the less explored corners of the world for Harpers outside the Atlantic Scientific American Smithsonian, the New York Times, as well as many other. He's the author of nine books and has performed at multiple events, lectured at Harvard and Yale and appeared on CBS, NBC, and NPR. And today we spoke about his new book in defense of sunlight We spoke about the value of sun exposure as well as vitamin D, why light is a master regulator, the influence of shift work, why cortisol rhythm dysregulation and the physiology behind this is so problematic The minimum effect of a dose of light as well as exposure and intensity How UVA and UVV wavelengths impact our physiology, the importance of nitric oxide production, and specific recommendations from his work, I found this book really fascinating, incredibly unique and really speaks to the nuance around light exposure. If you enjoy reading science writers' work, I highly recommend Rowan's book Rowan, so good to connect with you. Thanks for coming on everyveryday Wellness Thanks Cynthia, Re really good to be here. What do you think M people get wrong about the power of sunlight I think the part that we all tend to get wrong is that bad And we just we know that there are some things about the sun that we need to worry about The part that people don't realize is that There are so many beneficial aspects to getting a sensible amount of sun lightight. And I think that's the conversation that we all need to start having. BeCause I think for so many of us, you know, I grew up at the beach at the Jersey Shore for those of my New Jersey friends that are listening And that was a day when know sunscreen wasn't really pushed. I'm sure all of us had debilitating sunburns multiple times over. I mean, I was so tanned by the end of the summer. A some point there was this large pivot of just bringing awareness to sun exposure. And I think we're now at a point where things have the pendulum has swung the completely opposite direction whereere I think many people fear any sun exposure And I oftentimes will tell patients that For anyone that lives north of Atlanta here in the United States probably not getting enough sun exposure in the cooler months because we're so covered. You know, we have four seasons, just like you have four seasons, farther north of even where I am And so helping women understand that know that sunlight exposure, even getting some sunlight, has a lot of physiologic benefits. When you're thinking about the value of sun exposure and lookingoo at the research, what were the things that you found as you were starting to flesh out, map out this book in terms of quantity of time of sun exposed that seems to confer the most physiologic benefits Yeah, you know, I think you mentioned the really important factor We actually mentioned several really important factors there. I'm glad you wroub the pendulum because I think it's important to keep in context that the messaging we've received since that era of, you know, like body oil where we were all trying to get as tan as possible. So tanning beds. tanning beds They are all not ye can of worms. There are good reasons why the medical establishment wanted to really drive the message home to everyone that If the sun is not know your friend in un limited quantities and you really do want to be careful and avoid that The inevitable nature of pendulums is that they go really far and they they get momentum and they keep going. So now it does look like we need to maybe start to a little bit. But in terms of your question What's the key thing to understand? It's and how much time, it's really wintered. That's the question for a lot of us. like Most of us live in places where in summer we're just going get. All the sunlight we need to be healthy, just going about our day. But Yeah, if you're above like say, forty degrees latitude, you can't make any vitamin D from sun in the winter. even, you know, even if you could lie out naked in midwinter in midday in winter, it wouldn't help in terms of vitamin D So And it's when we get really deficient in D and probably other things that the sun makes that we start to see the negative health of that. So it's not about going to Canccoun and le in the sun for eight hours. It's making sure that we get some throughout the year if we can. Yeah, it's interesting. I always felt like I made up for the fact that I was probably not getting enough sun exposure because both of my boys swam competitively for years. In the summer, we had two meets a week where the parents were on deck at a pool standing in direct sunlight, even if you wore a little bit of sunscreen, we were getting so much sun exposure, even with hats on and visors and everything else. And so I used to always say that it's amazing to me how much better I always felt in spring and summer when I had more sun exposure. and how for many of my patients, I have patients that are so fearful of getting any sun exposure that I don't think we speak enough to this vitamin D piece And so when we're thinking about the value of sun exposure. It's not just synthesis of this pro hormone vitamin D, which is really critically important It's understanding that light in and of itself is a primary zeitgeeiber, which is this time ceue for our circadian biology. So let's talk a little bit about what sunlight exposure to our eyes, what that is actually doing for us physiologically. because during the pandemic, and my poor listeners have heard me talk about this a lot. One of the few things we could do was walk our dogs. and so our dogs got a lot of walking outside because we were bored right being at home. Yeah And so the joke being like, dogs were like,le know, these memes with dogs standing on top of cabinets, please don't take me on there to walk. But how that time period, that entire year of our lives where walking outside more without sunglasses and how that's become something that my husband and I crave, notot only is just bonding opportunity without kids but how we crave that physiologically. So let's talk about How light is this master regulator Yeah, and that is such an important part of it. And you're right, we all weirdly had that surreal pandemic era when Often our health improved because we weren't in an office all day I know for me, like I was getting a lot of long runs in 'cause I didn't have anything else to do. A lot of dog walks for sure. But yeah, so we have these proteins in our eyes that are similar to the ones that we use for provision for detecting light converting that in the brain into visual images these other ones called melanopsin, they don't contribute to visual images, they are just there. to kind of count up the light you're receiving at any particular moment and send those signals to the brain to tell the brain where and so that the brain will then tell the body where we are in the day night cycle, the circadian twenty four hour cycle of the planet And if you think about, you know, we're like a An organization built out of thirty seven trillion cells Most ofich no way of seeing what's going on in the outside world. So they depend on indirect messages to tell them where they are in their day when they should be active, when they should be sleeping, when they should be getting ready for food coming in And you know so all those cQues, which as you say are called zeit givers, like time givers, our cells depend on this information. And one of the most important pieces of information is what these melanopsyin proteins of the eye are detecting. they send the signal to the brain And then one of the things the brain does with that is decide when to make melatonin, which is a hormone that we're all familiar with. A lot of people have trouble sleeping, take it as a supplement the hormone that is produced in the brain and then travels throughout the brain and then the body and tells the cells, okay, night is here. so you know you might want to think about settling down for the night. Melatonin Q is all based on how much light is coming in through the eyes and not all the different wavelengths of light that are detected by the eye. It's primarily light in the blue part of the spectrum, which is the most common part of sunlight. Sunlight has all the different colors in it combined Blue is a big part of it So for whatever reason, the way the system works is these proteins in your eyes are counting how much blue light is coming in and then sending that message to the brain and the brain is deciding when to tell the body to go to sleep because it's night and when to stop making melatonin so that the body will start to wake up and get active during the day So There's kind of two parts to the light in that part of it. During the daytime, we need that signal of bright light hitting our eyes to let us know that it's day and so that the brain will let the body know it's day And then at night, we don't want that signal to be hitting us becausecause that'll trick the brain. You know, in ancient times, there was no light at night. was nights were super dark So that lack of light was a signal that it was night and the whole body should rest and restore and heal and then get ready for the next day. So we really do need those outer cues from light so that we can be like surfing that day night. wave and it's really important the health of all the cells in our body that we do that. Something I hear constantly from women in our community and something I understand personally is this Nothing about your effort has changed and yet our bodies are responding differently Your midsection feels different. Y blood sugar is much less stable and your cravings may have shifted And let's be honest, your energy probably isn't what it used to be As a nurse practitioner with over twenty five years of experience, I want to be completely transparent with you about why Estrogen is one of the body's master regulators of metabolic health. 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This is a targeted cellular support for the transition we are all in and's designed specifically for women in perimenopausea menopause and built around what actually is effective Go to wWW dot mitoQ dot com slash Cynthia and get ten percent off your first order Again, that's M IT OQ ot com slash Cynthia to get ten percent off your first order Well, and I think it's so interesting because, you know, you mentioned that Before we had electricity, there was a lot more darkness in our evenings. and I think about the technological advances in you know, my children's lifetime But the ability for people to be streaming twenty four seven to have exposure to electronics twenty four seven, to be able to essentially never leave your home and be able to order anything you want, you know, whether it's on Amazon or UberEats what have you And how the influence of our circadian biology is being so heavily altered and dysregulated given our modern day lifestyles As someone who just has created this new book that you're putting out into the world I can imagine that for you as you were writing the book, you probably have some genuine concerns about these alterations and these normal physiologic processes. I think a great deal as someone that used to work night shift in awa both as an ER trauma nurse, also as a nurse practitioner and how messed up my physiology was in my twenties and thirties but acknowledging there are a lot of people that do SHifF work. So how does our modern day lifestyle plus or minus shHifF workers or individuals who, know EMS workers, police officers, our health carere team that are out there How does that influence our physiology Yeah, I'm really curious about shift workers because we actually now have really good evidence that that shift work, being up for the night shift is really challenging on the physiology. It's, you know, you It's not what your body was designed for. L noobbody was doing shift work ten thousand years ago So it's really confusing to the body, the signals coming in. And what normally happens is the reason that we sleep at night is to basically repair everyday life, just the activity of everyday life creates damage and you know trash, just like if you think of an organization, some sort of corporation stuff goes wrong during the day and then you know you need or if you think of a factory, right You need maintenance all the time to keep things running. and you got to take out, you know, the trash, whatever like the waste products are that you make. It's the same with the body. You need downtime would you shut down the normal activity so that Things can get fixed and like the trash can get taken out And normally that happens at night. Like that's what we're designed for So when you change up that rhythm and you have to be awake at night. And the thing about shift workers is they're essential. Like society cannot go on without all those people doing those very important jobs in the wee hours but it is really challenging for there physiology because it's like the cells are like, well, do we shut when are we supposed to shut down? And brush it down to the day because I'm still getting the, you know, the ue from the light that I should be awake. When does the trash get taken out? It can actually be really complicated for your cs to figure out what they should be doing and when wouldould you scramble that That said, I think, you know, people can they they're also pretty plastic th thoseselves. they can adjust So probably it's better if you just consistency is really important. So like I I know a guy who's an astronomer in Arizona and he's awake every night through the night, but he has a super, super regular schedule. Like he's pretty much doing the same thing. at the same minute every day. like he goes for a long hike before he goes into You know to work to like the little like the little bike box next to the telescope where workks And so and he has no problem. He's like, this works for me quite well. I'm quite healthy. I mean I'm in my fifties, I'm healthy I haveve no trouble sleeping. So I think the like Your body can adjust, but the really hard part is if you're the type of shift worker that does not have a schedule And was that were you on one of those? Were you kind of cycling through? Oh, yeah, you would have three twels and I got to a point where I did better doing three night shifts in a row. And they trying to function like a human being on the other four days I was off. But I always felt very disoriented. I was never someone that stayed up all night studying. I was someone that genuinely needed sleep And I can tell you, even though I live fairly close to the hospital, I worked, There were many mornings when I drove home I don't remember from the time I left. And so the time I got home, which is terrifying. But I think it's you're in a semi conscious state driving a vehicle, which is to me now terrifying that I realize that. But I think for a lot of people and almost always we have healthcare professionals and EMS workers that listen to this podcast and' like, you know, what can I do? And I think for a lot of individuals, although you give the example of the astronomer who has figured out for himself because he has a consistent pattern to being awake at night and being asleep during the day. moreore often than not, shift workers have to flip flop back and forth with their normalcy of their lives. And that I think is more disorienting and probably is contributing to a lot of the health effects that we see for individuals that work night shifts or work swing shifts or flip back and forth And it's really speaking to circadian vulnerability. And this is something that becomes really critically important to realize as women are navigating changes in hormones, changes in neurotransmitters that heavily influence melatona and cortisol our circadian rhythm and why women suddenly start suffering from insomnia Some of it's because we're trying to do too many things, but more often than not, our physiology is no longer matching up with our circadian biology. And so not at all uncommon to see women in midlife that really start to struggle with sleep And so you too not just women. I mean, I know it's more common with women, but I definitely like insomnia kicked in for me in middle age for sure. Like I could just youum core modes were changing or something Yeah, no, absolutely. I mean, we make less melatonin after the age of forty. and there's definitely I've had guests on the podcast who are anti melatonin supplementation. and I always say if every other hormone is declining with the exception of cortisol Why not consider small like small dose melatonin if that's appropriate for you. So if anyone's listening, some medical advice, talk to your practitioner about that. But let's talk about cortisol because in opposition to melatonin is cortisol. And I think it is such a misunderstood hormone in terms of context You know, you talk about sunlight exposure, that's really when we're talking about these peak cortisol awakening response throughout the day, how it ebbs and flows, follows kind of a circadian pattern and then kind of declines as the day goes on when melatonin is being secreted in larger amounts Yeah. I mean, Cornwal Zal has a bad rap right now. in a sense, deservedly so because We all Most of us are making too much of it in a sense Again, I'm going to refer to, you know, ancient patterns ten thousand years ago Cortisol is a good thing in that kind of context where maybe regular life is a little bit less overstimulating than it is today So cortisol, it raises the activity level of your cells, including your neurons, so your brain, your body. increases the speed with which they make energy and they burn fuel. and you know, it actually makes your senses a little sharper, makes you a little quicker. All the stuff that you might need to survive in, you know, in a landscape, an environment that can be challenging or dangerous or whatever. likeike if you want to hunt food, it helps to have some cortisol. you you know, you want to like keep track of what's going on and who's around and where your kids are. It helps to have some cortisol. But what's normally supposed to happen is like you said, it's kind of this dance with melatonin where, you know, the light hits, cortisol will go up in response to light, but it willll also go up in response to stress Which makes sense, right? If something is challenging you, stress is just a challenge from the world You want to like raise your game and start burning some resources so that you can like deal with whatever that stressful thing is. But then what's normally supposed to happen is During the day, you know, you make some cortisol and you deal with whatever you got to deal with during the day and melatonin is not being produced And then the evening, the light drops You know, hopefully all the challenges are like put away for the day And at that point, you want cortisol to drop so that your cells are less active and you want melatonin to rise for that period of rest and repair Ned restoration that happens during sleep And so that's so and that, you know, that just fits in very nicely with the twenty four hour cycle of like twelve hours a day, twelve hours Now of course, things are wildly different from that So any sort of stressful event that comes along is going to raise cortisol and those stressful events don't necessarily sunset, right? And it's stressful that it can be even like thinking about anticipating the future stresses of the next day, like the bad meetings that are coming up or whatever so the body is sort of unintentionally revving you up to prepare for that And that means your cortisol iss not going to go down. your cells are not going to go into that that stage of rest and repair And so that's what you want to avoid. So it's interesting in terms of light light's not the pure answer to this. There's a whole lot of things in modern life that are factors Getting more light during the day can actually help you to drop those cortisol levels and raise those melatonin levels at night because it's all the contrast. L if your days aren't very bright, like you're spending most of your day indoors in fairly dim lighting, which a lot of us do now in offices then your body iss not getting that really strong signal It's daylight, it's time to do stuff, which you get when you're outside. So you're maybe a little less alert, a little less on your game than you would be if you were in natural light And then the contrast is going to come that night when maybe, you know, indoor like modern Environments yeah at night are not that much darker than indoor modern environments during the day So then your body isn't going to have that obvious switch where the light just suddenly like fades and it's like, okay, it's night, it's time to settle down, sleep. and repair So one way that we can deal with that cortisol melatone and dance is to make sure we're exposed to bright light during the day, especially our eyes Was there in course of writing the book, was there any minimal effective dose of light exposure, Was it fififteen minutes thirty minutes, ten minutes, five minutes, because inevitably my listeners will be curious to know Was there any defined minimum effective dose of sunlight exposure, obbviously without sunglasses, preferably morning light. But for those individuals who are like, I work in an office where there are no windows Yeah. For many years, I worked in hospital environments where I didn't see a lot of sunlight. so I acknowledge that sometimes we are dependent on our work environments and sometimes it does not align itself with this kind of support But if someone's thinking, I only have, you know, five, ten, fifteen minutes in the morning, I could sit outside and drink my coffee or have a cup of tea because I'm You know, now at a stage where my kids are independent enough, they get themselves up, get themselves dressed, get their breakfast and, you know, be heading to school. What was it that you found as you were kind of compiling the book and putting all this together Yeah, and there's kind of two components to that. There's the length of light exposure that you should get and the intensity of that light exposure. And the intensity part has been measured pretty well Ps measure light in terms of lux And you can you can download free apps for your smartphone where you can actually measure the amount of light that you're in with Llex It gets totally addictive. You're like everywhere you are like,, I wonder how many lucks But So it's shocking how much more light there is outside. We don't tend to realize it because eyeballs are really, really good at adjusting to the ambient lighting to compensate so that we can see things well. You know, you see that with your pupils as soon as you go outside, they become like little pinpricks if it's bright out there. So we're not as aware of it visually, but Indoors, if you check your light meter, you'll find that you're maybe in like two hundred lucks of light whichich is not, you know, it's it's actually pretty dim A bright office might be four hundred of light Like, you look like you're in a pretty bright office right now. You maybe in like, I guess like three hundred or four hundred Step outside onn a cloudy day and you're going to be in like ten thousand luucks of like twenty thousand lus and it's the clouds part and you got like full sun shining down on you It's like a hundred thousand lookus of light. So a hundred thousand versus a few hundred. is just you know, shockingly different for the parts of your body that are detecting that part and telling the brain Okay We are in light. now. this is like the real thing. And so what that means is that if you're spending your day indoors which most of us are forced to do most of the time You're not like your eyeballs are not telling your brain that you it's daylight They're like Oh, it's weird. It's kind of like, you know hazy out here. I mean, you know, it's like, It's not dark, but it's not light. It's in between So that's a confusing signal. So in terms of intensity You got to go outside and it doesn't have to be sunlight. clouds are fine, shade is fine outside. You're still going to be in maybe like to ten thousand Ls of light, even like under the trees in a park In fact, that could work great because then you're not getting any ultraviolet, so you don' have to worry about skin cancer, but you're still getting those really strong circadian rhythms. Then there's the question of how long to do that? And that's less well studied Any is better than none. I have questions about, you know, you hear a lot of people say you go out and get that like ten minutes of morning light like, you know, first thing And that can't hurt But I do wonder what like if you do the ten minutes and then you go right back into your two hundred lux, you know living room How much of an effect does that have? And I haven't seen anyone who's looked at that exactly There's a cool experiment they did in Colorado a couple of years ago where they took some, you know, healthy young adults And they tracked they put light meters on their wrists and they tracked how much light they were exposed to during a week of their normal lives in Colorado And I think, you know, these were like typical Colorado like you know, thirty year olds. They were out and about, they were walking their dogs, they were hiking. They're getting pretty good light during the day. I forget it's like they averaged nine hundred and sixty llux during the day, which is better than most of us But then they made them go camping for a week then track the light and track their sleep And when camping, they averaged like four thousand lucks, so like four times as much light on average as they were getting in their regular lives And the amount of time that they were above a thousand lux, which some scientists believe is the amount that you need to sort of register as daylight for your brain was many times larger than what they got just living their normal lives. and their sleep totally changed. They slept more and they went to sleep onene to two hours earlier and woke up one to two hours earlier. So just that week of camping, they kind of locked into the silver cycle a lot more closely than most of us did I think it's fascinating. I was just in Denver with my husband and you know, it's a mile above sea level And I remember saying like the sun feels so much more intense, which of course makes sense because it's at elevation. But what an interesting research article and how many people listening when they go on vacation or go camping sleep more deeply. They go to bed earlier because they don't have the confines of their modern day lifestyles maybe as heavily and readily upon them that, you know, that's usually what's contributing to you know why our sleep isn't nearly as good as it once was. And I think about you know, a lot of women that, you know, we spend, I don't know teen plus years when we're raising children. fifteen, I' saying fifteen because by fifteen, most kids are driving. so there's a little less hands oness of that stage, but fifteen years where yourour focus when you get up in the morning is making sure that kid is fed, bathed, ready to go to school or wherever they're going. and then suddenly you have a little bit more time. And I'm certainly in a stage in my life where my husband, our youngest will be going off to college in August And I was saying to my husband, like we've had so much more time over the past couple of years, much more so than we had in twenty years which has been in lightning So how many people listening are like, I'm finally at a stage where I could invest fifteen, twenty minutes of light exposure in the morning that maybe I otherwise would not have had the opportunity to do. So just to be thinking about things that we can be doing differently. And yes, you astutely mentioned, when we built this house, there's a lot of windows. We have a lot of windows. We did that purposeully because we wanted much as much light as we could maximize based on where we are geographically within our neighborhood. That's mean when people come to our house, the first thing they say is, wow You have a lot of windows Yeah, and that is definitely one of the answers for circadian rhythms, like especially in the winter when it's like not depending where you live, it's not necessarily that easy to spend a bunch of time outside Windows, you know, are your Circadian friend? comes to getting your sleep habits lined up and not just sleep but the health of All those cellular metabolism aspects of sun exposure or just light exposure. So yeah, hang out in the window. If you can't go outside, hang out in a window, that's facing the light. and that gets you most of the way there. Now you touched on it. You mentioned UV A, UVB. So for the benefit of listeners, just kind of differentiating. I think a lot of the concerns about sunlight exposure have centered around Burning. So UVB rays Right UVA, know the aging rays. And again, Irew up in I grew up in New Jersey in the eighties and everyone was doing tanning beds. and I always feel like I have to apologize to my skin a thousand times over. But I think for a lot of people, they probably are thinking strategically like I wear sunscreen to protect my skin, but yet they're not thinking about these other effects. So let's differentiate UVA from UVB just from a very basic way and then kind of pivot and talk about some of benefits of UVA exposure Because I think that women, especially middle agge think about like EVA as, oh, it's aging,fore I want to slather myself in sunscreen. But again, there are some beneficial aspects to differentiating the different types of light that we're exposed to Yeah, that's great question. And for sure, we want to differentiate. They are very different in their effects and their risks. And this is really just starting to come clear in the research like People are realizing like we can't justop keep talking about UV because that can actually be quite misleading. So all those different wavelengths of light, those different colors, all that really means is how much energy those different photons have. and photons are like little particles of light And you can follow the spectrum. So like red light has very low energy in those photons. It's you healing. know red light therapy has become a common thing No risk from red light because those photons of light have very little energy in them They kind of gentle thenen you know, you go through the rainbow and yellow has more energy, green has more still very soothing Blue has the most in the visible spectrum And it's energizing. is that it's that sign of daylight of high energy light. Then you go beyond blue, you get to violet, which is even more energizing, but we don't see it's just a very narrow band. And then you get to ultraviolet, UV And that's the highest energy of level of sunlight that reaches the Eth. And so scientists break up the UV part into UVA and UV B A has higher than violet or blue, but not as high as UVB. UVB is the super high energy light. And that is the one that causes sunburns. and that's the one that could it can cause skin cancer by like actually messing up your DNA. So that's the one that everybody focused on originally. It also makes vitamin D. So the body it's a challenge for the body to work with UVB, but it's actually really beneficial. It has so much power that it can change molecules and that's how we make vitamin D in our skin. But so that initial round that initial generation of sunscreens that you and I used to use back in the day. only blocked UVB At the time, they didn't think EVA was a real problem because it was lower energy. So like SPF on a sunscreen That just refers to how good it is of blocking a UVB But the stuff that blocks UVB doesn't necessarily block UVA It didn't block it at all back in the day with sunscreens. whichich everyone thought was okay, it turned out it wasn't. It turns out UVA also can cause skin cancer and definitely causes wrinkling through by more indirect means, it basically creates free radicals in the skin. And that's what ends up causing You know, skin damage and wrinkles and also can cause melanoma. Those free radicals can end up like making changes that lead to melanoma. So it was kind of an oops. Suddenly know the research came in and everyone realized we need to block UVA as well. So then we got the broad spectrum sunscreens that block UVB and UVA. And those are way, way better than the generation that came before They're going to get better again next year as some other new blockers are going to come in that they've been using in like Japan and Europe for a while and are more effective. So They're a lot better than used to be and they're going to get better still When we do block UVB Like I said, we don't make vitamin D. And one of the things that I write about in the book is over the past ten or twenty years, scientists have learned that in addition to vitamin D, there's a bunch of other beneficial compounds that get made in the skin when it gets hit with these various wavelengths of light. but especially UVB. So there's now good evidence that we want to get a little at least a little of that UVB. Like you said, not enough to burn. Like every scientist I spoke to said burning's clearly bad. It's a sign that your skin got so much like got overblown by so much high energy light that molecules are so damaged that the bice is just can to get rid of that skin you know, you like I don't know if you ever got a peel back in the day as a teenager on the Jersey shore, but I got a few in Florida. bad, right? But you want a little bit of that UVB to produce all these valuable compounds. there's no other way to do it So then it becomes a question of How do you get the good stuff without the bad stuff And the trick there is mostly time. like middle of the day when UVB is coming through because it gets filtered by the atmosphere when the sun is low in the sky. just a few minutes a day is enough for most people unless they live, you know north and it's winter time. But the rest of the year you can definitely get the UVBU on in just a few minutes. Yeah, and I think that's I mean, it's certainly validating because I think for most people They have concerns about whether it's squamous cell or basil cell or certainly the worst and most pathologic is melanomas, which you know, I think again, I go back to, you know the nineteen eighties and everyone was in tanning beds and you know, how many of my friends have already had more than one type of skin cancer. And so I think it's the Goldilocks effect when we talk about The right amount of sun exposure at the right time, not too much We're not looking to be bronzy and nowadays there's so many options for self tanners. No one needs to be getting Sper Tan. And certainly we know a lot more than we did before. You mentioned that there's emerging research about additional compounds beyond just vitamin D. Let's talk about these because I thought this is a particularly interesting aspect that you discuss in the book Yeah, this is one of the big things that came along starting about, I think twelve years ago, maybe when scientists started to go like Oh, maybe, you know, if this is true, what we're seeing Maybe we need to change the recommendations a little bit becausecause a couple of different research groups kind of simultaneously discovered When ultraviolet light Hit skin. L likeike I said, it can like change these molecules to make vitamin D And that was the only thing we knew about for a long time. then these scientists discovered that The other thing it does is when it hits the skin, it produces nitric oxide And that gets produced out of nitrates, which we eat in vegetables. especially leafy greens and some root vegetables like beets. the more nitrates you eat through your greens and your root vegetables. The more nitrates you'll get you'll have in your skin. And when ultraviolet light hits those nitrates in the skin, it breaks them apart into nitric oxide. And nitric oxide is an incredibly important molecule in the body. It's used for lots of signaling between cells, but it's also used to dilate blood vessels. So when nitric oxide 's producing the skin, it kind of filters down through the circulatory system. and when it hits the blood vessels, It causes them to dilate and that lowers blood pressure And so there's now been a lot of studies that have shown that you know, if you shine ultraviolet light on a volunteer in a lab setting, you will lower their blood pressure and it'll stay low for about an hour, even from like just, you know, ten minutes of light So then people start going like, well, wait a minute, does that mean that when people are out in sunlight, their blood pressure is getting lowered That could be huge because The number one cause of deaths in the world is cardiovascular disease, things like heart attack and stroke. And the number one way to reduce deaths from those causes is to reduce blood pressure. So reducing blood pressure can save millions of lives a year. A lot of medicine is devoted to reducing blood pressure And so suddenly everyone realized that sunlight does it. naturally and automatically So then people started questioning like the math, like If you are avoiding sunlight entirely to reduce your risk of skin cancer, that makes sense, but then if you're simultaneously raising your risk of cardiovascular disease, which kills a hundred times, two hundred times more people. Doid that make sense And what is there a place we can find to balance that and get most of the good stuff and minimize the bad stuff. So that's been like the conversations of the scientific community now. Nitric oxide super important one. Since then, they've also got pretty good evidence that Compounds that are produced in the skin reduce inflammation throughout the body. And I know you've talked about inflammation on your show before like that's a really that's a key for all the diseases that are associated with aging They seem to all have an inflammation component and keeping down that sort of chronic inflammation that creeps up as we get older is one of the best things you can do to promote like long life and healthy living you know, into your later years. Well, and I think that we physiologically are connected to the earth And we in previous generations, one hundred plus years ago, thousands of years ago, we got a lot more sun exposure than we do now, not so that we're burning, but that we're just having our days were so much in alignment with our circadian biology. I love that you brought up nitric oxide, which I'm so glad that you did. Nitric oxide is so important. One in three women will die of heart disease We know that as estrogen is declining, estrodol, we are getting a reduction in nitric oxide production. So this is one of many reasons why this lifestyle piece to hairy menopause and menopause really becomes critically important and understanding that, yes, supplementation with estrordol can boost nitric oxide signaling. And know my background is in cardiology. so That whole endothelial dysfunction that comes with declines in estrogen and changes in nitric oxide signaling, you know that there's a lot to this conversation that I think is so important and if something as simple as sunlight exposure can help produce and support endogenous production of nitric oxide, I think that that is really interesting and telling. And again, just yet another layer to this conversation about how light exposure is supporting our bodies physiologically. I think that what I found really interesting is that the effect of light on nitric oxide production, I believe is independent of vitamin D, which I thought was really interesting in terms of, I think it's thought of that vitamin D as the precursor synthesizer or you know, the component to the conversation, but it's actually independent of that, is that correct? It is and that's you bring up a really important point there. because we've known about vitamin D for so long, like we discovered Literally a hundred years ago um, you know, if you didn't have any vitamin D in your body, you would get rickets, especially as a kid, you'd get rickets. So we figured out there was this like substance we didn't know about before called vitamin D that we had to have in our bodies to prevent rickets. So then vitamin D was on everybody's radar. And then they started noticing in the fifties and sixties people with highigher levels of vitamin D in their body had lower rates of everyvery disease, you can think of all the ones you mentioned and more Mental disorders, physical disorders, you name it, like low D raised your risk of incidence for all of them. So you know, by the eighties, we were all starting to think of vitamin D as kind of this wonder drug. And that was produced by sunlight. but If you if you want in the sun, you also raise your risk of skin cancer. So then the recommendations became Skip the sunlight and just get your D from supplements But then there were all these very large randomized clinical trials that were done to prove that Dupplementation would reduce the rates of all these diseases. And they pretty much all failed to do so. You know, it's just a huge body of work now showing that Vitamin D pills don't do anything for most people. If you have really, really low levels of D, it's a good idea to take them. Otherwise, you know they're basically just placebo hills. But so Everyone had assumed because we knew about D, that yeah, like you said The reason sunlight was good for you was simply because it produced vitamin D. So then people when they found about nitric oxide, they wanted to start doing tests to see, well, is it just So I'm like, is it just vitamin D or is it something else And vitamin D is produced by UVB, like we said before, but not UVA So some of the dermatologists who did the research, what they would do is they would just shine UVA on volunteers to see if that would reduce blood pressure, right? And it did. like so it was that blood pressure lowering effect was from the sunlight, wasn't indirect via vitamin D. So they proved that But then they also went and checked, you know, like they checked everyone in the United States pretty much like comparing NASA satellite data from how much light everyone gets to blood pressure, vitamin D, and so on. And what that all showed was that yeah, like UVA will lower your blood pressure a little bit, but UVV actually lowers your blood pressure even more. It's more important. And it was not because of vitamin D. Like Vitamin D does other good things for you, but the blood pressure lowering seems to be fifty percent from the UV, and the other fifty percent is actually from the warmth. Like warmer temperature will also lower blood pressure As someone that for many, many years aggressively managed aggressively manage blood pressure in cardiology It's interesting to know and to think about how many of my patients that were farmers And this is totally tangential conversation, but the joke is if you have a farmer that comes to the hospital, you know they're sick because they never come to the hospal, to they rarely want to be seen in clinic And How many of my patients were Ver physically active, outdoors were active from the time they got up to the time when they went to bed and how rarely I saw patients that were farmers that needed blood pressure medication. Now, I granted I worked in clinical cardiology for sixteen years, but they generally tend to be pretty darn healthy until they weren't. So they would go years and years and years of never seeing clinicians. It would only come in when they were ghastly sick, usually something they had put off dealing with because you know the first wives would say, You know he's sick if he's here in your office. Yeah. Yeah. ye. I think that' I mean that's an important. like we can definitely learn a few things from farmers and other people who are working outside. Like one of the things I recommend in my book, like all this new signs on light It's early days, so we still have a lot more to learn. Everything's going to change a little bit as more data comes in. But what's if you just pull the camera back even further, what becomes super obvious is that Being outside is just healthy for you in every way you can think of. Being standing up or moving around and being outside is Always good sitting on your butt and being inside tends to be bad. So you don't have to overthink it too much just like If you're making lifestyle changes that get you outside more often, It's going to be good. And like, you know, you don't have to worry about the micro details too much probably That's why I think I'm such a huge fan of people having pets because it usually gets them outside. It allows you to be more social. We know that that socialization piece is also important. But if you're having to walk a dog multiple times a day and you're getting sunlight exposure with each walk, that is ultimately definitely beneficial So In the course of writing the book and looking at this from the context as a middle aged person yourself When you're talking about light optimization, you're making recommendations, how is that showing up in terms of symptoms or research on symptomatology? I would imagine that Light exposure or light optimization is improving sleep is improving mood for so many people, and yet it's such an easy intervention and likely one we aren't talking about enough Mood's so big. Mood is a huge part of it. I wanted to talk about that too because Yeah, it's funny, you know, sometimes Mood gets u sort of like pushed off as more a secondary type of thing when health is involved. like it's not as like physiological as blood pressure, right? But mood is kind of the whole game in a sense, right? Like If you're talking about rich, enjoyable life It's all about mood. So mood almost should be the first thing that we focus on. and there like I don't even need to Hell, you know, the people listening, everyone knows like If you're out and you get sunlight, you feel better. And there actually we do understand the mechanisms there. when Ultraviolet light hit skin. The skin cells actually That triggers dopamine production in the brain. couple other feel good things as well, but the obvious one that's been studied is This released of dopamine in the brain And that would go that means like way back in the day, it was a reward signal, like like other dopphamine signals like The body was sort of like encouraged to seek out this light. I think, you know, basically it was a way of getting you up and out and about your day you know, like it was attractive to go out and get that hitid dopamine. So we really do, you know, We feel good when we're in And that can go too far. L the people who do you know, hanging on the Jersey shore all day long, they're a little addicted to that on exposure probably to an unhealthy degree. But a little bit of that is not a bad idea. Right. And I mean, it's like anything, that Goldilocks effect. I mean, ultimately We're talking about a dose dependent effect in a beneficial kind of beneficial alignment because for so many people And yes, I have friends that I grew up with who were obsessed with tanning. And to your point, know those dopamine hits, whether it's scrolling on your phone, which we know is not physiologically beneficial to us. as organisms versus getting light exposure for a specified amount of time can have a huge amount of benefit. If we're kind of looking at An evidence based kind of protocol. if we're pulling a galt from the book What are your recommendations about morning midday or even evening protols around light exposure. It could be artificial light, it could be sunlight exposure. What are you generally recommending to individuals So I think what makes the most sense is Get that morning light anytime you can. Morning light is not going be damaging. It's very low in UV But it's going to give you that blue light signal that's going to raise your alertness, basically raise your performance during the day and improve your mood. that't they' also like good evidence that morning light is good from a mood perspective No risk there. If you want to get the UV benefits, that is going to be more of a, you know, expose S of your skin to the sun between say ten and four And midday is great. Dpends. All of this is so contextual on where you live though and also what your skin tone is like because the darker your skin, the more resistant you are to undamaged and the less you have to worry about skin cancer, but also the harder it is for you to produce vitamin D and some of these other compounds because you just have more of a natural sunscreen basically So the recommendations really need to range depending on skin tone and where you are in the world by one way Again, that the scientists I talk to would sort of just like simplify it is never burn N get anywhere close to burning. So err on the side of getting less rather than more, but get a little. donon't get none. No matter who you are, don't get none. Even if you have like fair skin and you know, reddish hair and you're extremely susceptible to sun damage get a tiny amount, but just, you know do get outside And the sunscreen can actually be super helpful because It doesn't want one hundred percent of UV. Like it'll block ninety to ninety eight percent of the UV But that's still what's a teet te weeny bit through. and So Again, it's like Get outside because indoors, you get zero. Th then dark nights are great. If sleeping is an issue, the darker nights can help and it can actually help you go to a deeper level of sleep, a de deeper, more healing level But then I actually think another another great great and safe move to make. is, you know the park move or the forest move, where you're outside, but you're not exposing yourself to super intense sun All these photons of light, they bounce off the atmosphere. and so they're finding you in small amounts indirectly. So when you're underneath a forest canopy, it's kind of like a very natural environment for human beings. It's where we evolved and you're getting a really gentle, but full spectrum mix of light. So it's kind of like the whole food. If you think of light as a nutrient, that's the whole food that has all of the important elements in it, but nothing in too great a quantity. I think it's so important just to keep things in context. and it's not to suggest that you, I do a tremendous amount of travel as I'm sure that you do in the process of book promotion and sitting in airports in the evening where you're underneath a lot of artificial light That eighty twenty rule of if eighty percent of the time, you're getting adequate light exposure, you're not underneath artificial lights all the time. I know in our house, we tend to dim things down. We have dimmers on everything. That really helps. Just to kind of round out the conversation. you had alluded to some new technology in terms of sunscreen. of course The EU and just about everywhere else in the world they are light yearsars beyond us in terms of product development. What are some of the new sunscreens that are coming that are more effective or more efficacious for being able to filter out the things we don't want and allowing us to filter in the things that we do So the reason the EU and the Japanese sunscreens are different is because they have different rules In the U.S, sunscreen is regulated as a drug which is how they can, you know, they can say that helps to prevent skin cancer. That means your drug So there's all this required safety testing, like a lot of hoops you have to jump through on the safety testing to you know, to be a drug on the market. The EU, it's a cosmetic, so it doesn't have that level of safety testing. For a long time The EU was using certain filters that were not had not been approved in the US because all those poops had not been jumped through. Nobody had done all the safety testing, paint in the butt, noodybody wanted to do it So what we were tend like right now in the US, we use this generation of filters, especially oxybenzone for blocking AVB An avo benzone for blocking UVA. And like I said, they're way better than what we were using in the seventies and eighties They still there's a bunch of red flags about their possible role as hormone disruptors. allowed to say they're absorbed into the body in greater quantities than we used to think It's somewhat problematic. They also don't do a great job of blocking UVA. They actually let the lower end of the UVA energy spectrum through They've been the best that the U.S. had to work with for a while They just changed the rules. I don't know, justust a couple months ago, I think it was. where they're not going to require that safety testing for these ones that have been used in the EU. And the reason is that, well, look at the EU. they've been doing that using these things for twenty years. We have like a real world safety test people aren't growing third eyes, they're probably pretty good. So those are going to start hitting the market. And I forget that the name of the first chemical is it's going to hit, but there's going to be one and then there'll be more after that. You know I would say I have some hesitations about sunscreens that have oxybenzone in them. I think it's very low risk, but it's not no risk. So once you're seeing ones that are moving beyond Oxybenzone, I think that that's what to look for. Everybody's going to move away from oxyenzone as soon as they can, I think Yeah, a lot of the zinc based sunscreens are what seem to be quite popular right now. Well, I've so enjoyed this conversation. Rowan, please let listeners know. How to connect with you outside of the podcast, how to get access to your new book. This podcast will be released right around your publication date to my website is just Ranjacobs.ot com and my contact info is on there. So yeah, I would love to hear from anyone who's got more questions And the book is in defefenseive Sunlight and that It will be in stores everywhere as of june sixteenth and online too Congratulations Thanks so much. Thanks for having me so too If you love this podcast episode, please leave a rating and review, subscribe and tell a friend