Defiant Health Radio with Dr. William Davis
Defiant Health Radio with Dr. William Davis
What happens when you deprive yourself of blue light?
Science journalist Lynn Peeples did something extraordinary: She spent 10 days in a nuclear bunker exposed only to dim red light but no blue or other visible wavelength of light. She also rid the space of all clocks or other time-indicating devices and even avoided having any human contact. What she learned opened up numerous questions on how to best manage our day-to-day light exposure, wavelengths, and the implications they have on the quality of sleep, our moods, even various aspects of health and performance. After these sorts of unique experiences, along with discussions on circadian rhythms with numerous scientists working on this topic, Lynn comes to some unique conclusions.
Lynn is the author of the book “The Inner Clock: Living in Sync with Our Circadian Rhythms” in which she explores the role of purposeful management of your circadian rhythm, your inner clock, for management of energy, focus, and mood. Here, Lynn and I talk about her novel insights, along with practical advice on how to better manage your light exposure and circadian rhythm.
Lynn's book, The Inner Clock on Amazon:https://www.amazon.com/Inner-Clock-Living-Circadian-Rhythms/dp/0593538900/ref=tmm_hrd_swatch_0
Lynn's YouTube channel: https://www.youtube.com/hashtag/lynnepeeples?app=desktop
YouTube channel: https://www.youtube.com/@WilliamDavisMD
Blog: WilliamDavisMD.com
Membership website for two-way Zoom group meetings: InnerCircle.DrDavisInfiniteHealth.com
Books:
Super Gut: The 4-Week Plan to Reprogram Your Microbiome, Restore Health, and Lose Weight
Science journalist Lynn Peoples did something extraordinary. She spent 10 days in a nuclear bunker, exposed only to dim red light, but no blue or other visible wavelength of light. She also rid the space of all clocks or other time indicating devices and even avoided having any human contact. What she learned opened up numerous questions on how to best manage our day-to-day light exposure wavelengths and the implications they have on the quality of sleep, our moods, even various aspects of health and performance. After these sorts of unique experiences, along with discussions on circadian rhythms with numerous scientists working on this topic, lynn comes to some unique conclusions.
William Davis, MD:Lynn is author of the book the Inner Clock Living in Sync with Our Circadian Rhythms, where she explores the role of purposeful management of your circadian rhythm, your inner clock, for management of energy, focus and mood. Here, lynn and I talk about her novel insights, along with practical advice on how to better manage your light exposure and circadian rhythm. Welcome, lynn, thanks for joining me. I know you came. I heard about you through Martha Carlin and she has some terrific ideas about your special insights into circadian rhythm and related type topics. How'd you get involved in this in the first place?
Lynn Peeples:Well, I, you know, I think the roots of it really go back to growing up in Seattle. So I grew up in this place where the winters were very long and very dark. I, like a lot of us, was at a high school that started at 7.30 in the morning, which for weeks of the year meant going to school in the dark, and I kind of yeah, I always had this sense that, well, I didn't sleep super well, and then I had this like ebb and flow throughout the year in my mood and in my energy and just felt kind of out of whack. And then it wasn't until I moved away from Seattle and went to college in Minnesota, where it was in the wintertime, it was very cold but also very bright, and I just remember starting to feel better. And then it was moving back to Seattle, which was about 12 years ago now.
Lynn Peeples:I had an opportunity to tour the Mariners ballpark Then it was called Safeco Field, mariners big ballpark, then it was called Safeco Field, but they had just installed circadian lighting in the locker room and I had no idea what that was about. But it was also an opportunity to go to my favorite ballpark, where my home team played, and tour around. So I went in there, learned about this lighting that they had installed, that they would brighten and enhance in the blue wavelengths before the baseball games and then dim and warm the hues of the lights after the games. So it was supposed to energize the players before the games, calm them down after, help them sleep. Know what was this circadian thing about, and could just the idea behind this help explain some of my, you know, lifelong struggles with energy and sleep? And then, I mean, things exploded. I just started connecting a lot of dots, talking to hundreds of scientists about how we have disconnected ourselves from the natural cycles and everything that is doing to our bodies.
William Davis, MD:So you subscribe to this notion that early morning blue is essential for alertness, concentration et cetera.
Lynn Peeples:Yeah, and for just setting our clocks to the natural cycles, so right, it's like the kind of direct impact of that light on our energy levels and everything, and then plus setting us up for success throughout that day and the next.
William Davis, MD:Absolutely, it's just one part of the equation though how are you managing blue later in the day?
Lynn Peeples:Yeah, so my day I really do, yeah, as you said, ascribe to trying to get that first light of the day, whether that's trying to get outside, which is the best, or being close to a window as you can see, at least right now I have a big picture window right by my desk, so I'm super fortunate there and then also kind of filling in where daylight can't reach with some of the modern lights that do have some ability to enhance and have more blue color.
Lynn Peeples:And then at the end of the day I do the opposite I cut the lights in my apartment and if I'm over at a friend's house or out and about, sometimes I'm obnoxious and I do wear some blue light blocking glasses. But it's really about, yeah, brightening the day and darkening the night. And it's amazing, I haven't thought about it, but we don't. We evolved with these fancy rods in our eyes that really can adapt to darkness, and so I I can get by with just these electric candles that I have around my apartment, which just give off this warm glow, right, and that's, you know, it's enough to see. So, yeah, there's many tools out there.
William Davis, MD:Have you had a chance to incorporate red infrared into your schedule?
Lynn Peeples:You know. So that's sort of outside the scope of my book. But I do have some interest in that and have been sort of researching it on the side and do play around with red light. I don't know where the date, I'm sure you know more than I but it seems like there's some growing data that it can help heal and do various things for our bodies. So I've been using it on some joints that have been less than healthy to see if that helps. But generally speaking, I mean the red that I used in the scope of circadian rhythms in my book is just for the point that it doesn't affect our circadian rhythms like blue light does. So when I did an experiment where I stayed 10 nights in a nuclear bunker, for example, I had the whole bunker set to just a dim red light because I was experimenting on what would happen to my body. So I wanted to eliminate any sense of daylight. So I use red light.
William Davis, MD:Tell us more about that. Why is that?
Lynn Peeples:Yeah. So I was seeking out a space where I could kind of go to the extreme and cut myself off from any cues that my body could use to tell day from night. Because that's our modern world and that is really the problem. That's how we're disconnecting ourselves in these rhythms that our bodies evolved to do the right things at the right time, without access to the cues, primarily light and dark, while the planet spins. So without that, yeah, we're disrupting our circadian rhythms. So I was trying to cut myself off from daylight as well, as you know, obviously, any clocks that are going to tell me the time, or any other human beings or creatures that also have rhythm that could give me any clues.
Lynn Peeples:And the best thing I found was via Airbnb. This man in Arkansas had bought a former Cold War era nuclear missile silo from the government, had gutted it and refurbished it into a fancy Airbnb, and so I got in touch with him and stayed in this. It was the command control center for this nuclear missile. I stayed down there for 10 days and he helped me. Just, you know, cover every clock that was visible and, you know, set these LED lights to be red and dim, just enough to see, but not enough to mess up my inner clocks. What happened? And oh, and I also big important point I decked my whole body out with various devices that were measuring my rhythms. So I had little buttons taped to me that were measuring my temperature. I was wearing a glucose monitor. I obviously was, as you might guess, wearing garments and various devices measuring sleep and heart rate. And then, at the end of the experiment, so I was uploading all this data and then I worked with scientists to look at these rhythms, to see what actually happened over those 10 days.
Lynn Peeples:And yeah, sure enough, my body fell out of sync with the sun, it drifted, and, what's more, that these rhythms in my body fell out of sync with each other, and so it's much like jet lag. So we've all probably most of us at least, have experienced that to some extent in our lives. But this was essentially an extreme form of it. I, you know, drifted later, which a lot of us naturally do, because, on average, our inner clocks run a little longer than 24 hours, which is why we need to keep sync to the sun, because it kind of keeps pulling us back to be closer to that 24 hour day.
Lynn Peeples:But my heart rate rhythm and my temperature rhythm. These, you know, fell out of sync with each other and that translated into I didn't feel so well, you know, my, my thinking was slower, my coordination was down. I was actually practicing juggling in the bunker. I tried to teach myself to juggle all kinds of interesting things to fill the time, but I was taking notes on a voice recorder and various things and I could really see from the data afterwards at about the point that I was feeling pretty miserable was when the data showed that I really fell out of sync and it was also kind of the extent or the amplitude of the rhythms in my body flattened. So I just I really I lost rhythm.
William Davis, MD:What became of mood?
Lynn Peeples:Yeah, the mood followed that too. So it's really a body and brain phenomenon. So I a body and brain phenomenon, so I, yeah, I felt more depressed, I felt more anxious. I also I struggled to sleep, like it was sort of you know. I felt like I just kind of wanted to nap all the time. I really lacked, lacked that rhythm. You know that awake during the day, sleepy at night, and then you know the the positive energy was essentially drained from me.
William Davis, MD:Did any of your devices give you any kind of feedback on sleep cycles?
Lynn Peeples:Yeah, so I was tracking my sleep cycles Definitely lost. I mean, if we're talking about the detail, you know I could see that I had less REM sleep, for sure, and uh, heart rate, you know, didn't drop as much at night as it did before the experiment no, it's really interesting it was kind of the same like the amplitude of my rhythms, so that included, um, yeah, heart rate, temperature and sleep. It was just, yeah, everything kind of flat lined would you learn um.
William Davis, MD:Would you learn with blood sugar?
Lynn Peeples:blood sugar. It wasn't as like obvious, but I definitely it did fall out of sync too with the other rhythms. And you know it's a complicated one because it's like you know there's so many factors going into what you're putting into your body. But but yeah, the blood sugar spikes did get kind of a little more extreme because, as we know, if you're not eating when your body is primed to handle those incoming calories, it's not going to, you know, serve you as well. Your insulin and everything is not going to be ready to tackle that. So you know it's hard to infer too much, but you could see some greater spikes and again, you know the overall rhythm was a bit out of sync.
William Davis, MD:And you managed to maintain a healthy diet during the entire experiment.
Lynn Peeples:I did. You know, I went down there with a bunch of bags of Whole Foods groceries and I mean the one kind of fun little anecdote that came from that. And this was, I swear, not planned, but it was two days before the end of the experiment, I believe. I was running low on food. It was dinner time, so I didn't plan this perfectly Right. But uh, I you know I used to always like breakfast for dinner. So I was like, okay, I'm out of like my main dinner foods, but I have, I still have some pancake mix and some blueberries. So I made myself a blueberry pancake for dinner that night and later, when I went back to the data, it was clear that I was actually eating that blueberry pancake in the morning when everybody above ground was also having breakfast. So I thought that was amusing.
William Davis, MD:Anything interesting with regards to dream content?
Lynn Peeples:Ooh, that's a good question. You know, I do not remember anything really standing out except and I did make a note of this but didn't really do anything with it I did have moments where I'd see light, like I'd close my eyes and there'd be kind of these flashes of light. It was almost like my brain was just craving daylight. So I would see these, yeah, almost, I mean just really vivid, kind of bright.
William Davis, MD:Why did you choose to use a low-level red light the entire time?
Lynn Peeples:Because the science shows that red light is going to be least impactful to our circadian rhythms. Because we have these third photoreceptors that were only recently discovered in our eyes right and those. They act separately from our visual system, but they're there. They're constantly trying to pick up cues from from light and dark. So they're looking for the intensity of light and they're really keying in on blue wavelengths, because that is the main kind of wavelengths that the sun's pumping out. In the middle of the day it's a full spectrum, of course, but the peak is really in the blue wavelengths. So when you get out to the reds, that's going to be more kind of. You know, end of the day you're going to get a little more of the red coming through, but it's just less likely to tell your body it's daytime. So that's what the scientists really kind of urge. You know, at the end of the day you want those warmer hues and then red light is least likely to confuse your brain.
William Davis, MD:So you do this crazy 10 day experiment? What happened when you finished, when you left?
Lynn Peeples:Yeah, well, first it was just, it was really wild to step up from that bunker and see the sun. I was, oh my gosh, I was blinded, so my eyes had not seen that for a while, so I was like I had sunglasses on and it was cloudy, but I was still kind of blinded by the light, literally. And then it took some days for my body to get back in sync. And again, you can compare this to maybe traveling internationally, because, also it's part of my book, I did go to Europe for a while to do some reporting and I came back and it was a similar, similar thing of trying to readjust right after, you know, crossing several time zones.
Lynn Peeples:So, yeah, it was probably about a week before I really got got my rhythms back and connected again. But yeah, but it was, it was a really. It was really fun, yeah, and it's interesting experience kind of going, going, going through those rhythms with the scientists, you know, drawing these diagrams and graphs, looking at how these things matched up or or didn't over the course of the time down there did you manage or manipulate your vitamin d at all?
Lynn Peeples:oh, I did not. No, I mean obviously. Yeah, that's one component, right? If I'm not getting any sun, I'm not getting any natural vitamin D. So, yeah, maybe that was part of it. Inherently, I was craving that, so I did spend a lot of time outdoors when I got out. I live by a park here in Seattle and I do like to walk around green light here and I was doing that a little extra. Plus, I could see color for the first time in weeks, cause when you live in dim red light, you don't see much color. So I was really happy to be reunited with color.
William Davis, MD:I'm glad you made that point about getting sunlight is the best solution, Cause I do see a lot of well, I think red light has a role, as you know, a different kind of role than blue, but I see people saying things like I live in Honolulu or Phoenix or Miami and I get lots of red light. No, no, go outside, Go outside. You can't do any better than sun.
Lynn Peeples:Oh no, we evolved for this. Yeah, we evolved for the natural sun. We evolved for this. Yeah, we evolved for the natural.
William Davis, MD:Natural said. So what have you learned, Lynn, that you've applied in your own life? Now understanding what you know about the circadian rhythm.
Lynn Peeples:Yeah, so I've realized that you know, like a lot of us, without knowing it, you know I've cut myself off from a lot of these important cues. So I was talking earlier about, you know, brightening the day and darkening the night. So that's definitely one. Got my blue blockers. Oh, nice, well, actually a key to that. So it's and I'm sure you're probably aware of this, but they do like lens makers are really kind of pumping out these blue light blocking coatings on a lot of prescription lenses that you can buy. But if you're wearing those during the day, that's not really necessarily helping out your inner clocks, because we want to really get as much blue light as we possibly can during the day. At night, yes, blocking that blue light could benefit you, but we kind of need to maybe be watching out for that. It's not filtering a ton. So if you're really out enough during the day, even if you're wearing prescription lenses with some blue light filter on them, not a big deal, but just want something to be aware of. Yeah, so I'm really I'm trying to just get outside more Morning's critical, but really throughout the day, just the most light daylight we can accumulate, the better, and there's some more and more research coming out, even just in the last few months, about how it really is across the course of the day, just the more light we can get, and then contrast that with as dark as we can get our nights. Now research is finding that on average, we live longer. I mean that goes hand in hand with being healthier, but really interesting.
Lynn Peeples:And then the other components, though beyond just the light and dark, is thinking about really, what else are we doing or telling our bodies? What other signals can we give our bodies that it's day versus night? And if you think about how we evolved, you know our ancestors were not eating 24 seven. You know they tended to eat during the daylight hours. You know maybe there'd be a hunt, bring back the animal or they're out. You know harvesting berries right, they were eating during the daylight hours. They weren't going out in the dark. It was risky and unsafe. And so that's our.
Lynn Peeples:Our bodies evolved to really be able to handle incoming calories during the day and we peak in our ability to do so late morning, early afternoon.
Lynn Peeples:So it's sort of the opposite, or close to the opposite, of a lot of the Western diets out there, where we really concentrate our calories at the end of the day we have this big dinner and sometimes that bleeds into like the later evening hours and the science suggests that stopping any incoming calories at least three hours before bed really serves us well and that allows us it'll be easier to fall asleep, it helps our inner clocks stay in sync and it improves our metabolism less likely to develop metabolic disorders, if we can really consolidate the hours that we eat, keep it earlier in the day and then try not to have that midnight snack or a sip of wine or anything else that's going to confuse our inner clocks.
Lynn Peeples:So I think it's yeah, it's the kind of the three C's is what I've talked about. So it's that contrast of light and dark. It's constricting I've talked about. So it's that contrast of light and dark. It's constricting your mealtimes. And then the third C I like to talk about is consistency, and this is becoming more and more important. The science is really underscoring that going to bed, getting up, eating, exercising, doing these things at the same time every day helps our bodies predict and prepare for those activities and that's really going to help our health and happiness and productivity and performance all those things.
William Davis, MD:How have these insights led to any change in sleep habits?
Lynn Peeples:Yeah, I really am patting myself on the back. I feel like I've become much better about being consistent. You know, like I on the back, I feel like I've become much better about being consistent. I break the rules. Hopefully we enjoy social lives and doing things that might mean compromising here and there.
Lynn Peeples:I now try to go to bed between 10.30 and 11 every night and tend to wake up and get up around 7, 7.30 every day and that shifts a little bit depending on the time of year. You know, here in Seattle there is a huge swing in when the sun rises across the course of the year, so it's easier to get up early in the summer. But generally speaking I feel like I am, you know, a lot more consistent with that and I really have tried to embrace this the meal timing bit. So if I'm at least not out with friends, that I'm really trying to embrace this, the meal timing bit If I'm at least not out with friends, then I'm really trying to cut off.
Lynn Peeples:I stop eating anything after about seven. No snacks. Try not to have that glass of wine later in the evening that I used to have, I found because I was wearing Fitbits or other trackers. While they may not be super accurate bits or other trackers. While they may not be super accurate, they do help. You see trends and I could tell that my sleep was way higher quality if I would be consistent and if I didn't confuse my clocks by eating too late.
William Davis, MD:And it helps, doesn't it, to remind everybody, this is not a phenomenon unique to humans.
Lynn Peeples:No, right, no, all life, just about all life that we've found, evolved with inner clocks and for similar reasons, right Again, if having. I don't know if I've mentioned this yet, but I mean we have trillions of clocks in our bodies, like every cell in your body has a clock, and we evolved with these so that they would, you know, coordinate with the environment and coordinate with each other to prime our bodies to do the right things at the right time, so we can, you know again, handle those incoming calories or defend ourselves from any pathogens that are trying to break through, right Like, if we have our defenses up all the time, we're going to run out of energy. So we have these ebbs and flows in all our body systems, and that's the same for plants, it's the same for animals, you know, down to microorganisms. We're finding that inner clocks really kind of pave the way for survival.
William Davis, MD:Speaking of inner clock, could you tell us about your book?
Lynn Peeples:Yeah, so yeah, my book. It came out the end of September of 2024. It's called the Inner Clock and it really does. It tells the story. You know, as we've hinted at I've put myself in the story a bit with some personal experiments the basic biology of the circadian system that we now are really grow, have grown to appreciate all the more for how it impacts our overall, overall health, how it impacts our productivity, our performance, whether you know you're thinking about your workplace and you know when you might be primed to do the best work or have a more productive conversation with a colleague. So if you're an athlete, you know how can you optimize your performance.
Lynn Peeples:All these things really do lean on the health of our circadian system and timing our days. So I talk about, yeah, the underlying science there. What modern life has you know, unfortunately, done to keep us from being optimal in those regards? And then what we can do. And there's just really, as I've hinted, some simple things that we can do and there are a few more, maybe more surprising tools that we can enlist to improve our health and then even kind of hack our rhythms to go even further. Some really cool research coming out of NASA and DARPA and elsewhere, from independent scientific labs that are looking at. Now that we understand this science better and now that we have this technology emerging, how can we really leverage this to further help human health, and then also think of it society-wide? What can we do about daylight saving time and school start times and these other factors that are affecting us that we may not have been thinking about too closely before? So what's?
William Davis, MD:your opinion On the whole, the wholesale conversion from incandescent to blue LED, blue dominant LED, all times of day. Has that been a benefit, Putting aside the energy saving issue, the human issue, has it been a beneficial thing or a harmful thing?
Lynn Peeples:So I think the science coming in on the whole suggests that could be a more harmful thing. So incandescence we were getting some wavelengths that we are no longer getting. Some interesting research coming out now about violet light, for example, that is just completely absent from indoor environments, both because our window coatings are filtering a lot of it out, plus our lights are not providing that, and we're finding some health repercussions of blocking violet light, for example. But yeah, and at night, if we had incandescent lights on, there was less of that blue light confusing our inner clocks During the day. You know, maybe LEDs have a slight edge over incandescent, but again, maybe because the lack of violet light, you know it's. There's a lot of variables at play here.
Lynn Peeples:But the interesting thing and the unfortunate thing is that LEDs you know it's good that they're energy efficient, right, there's a reason that we've made this transition and that is great for for the climate, for our environmental future.
Lynn Peeples:But because they last so long if people have invested in this the climate for our environmental future but because they last so long, if people have invested in the cheap, standard LEDs, it's probably going to be a long time until they consider swapping those out and we know now that their technology is advanced and we can get LEDs that can be way healthier. We can have LEDs now that are tunable, where we can brighten them, dim them, change the wavelengths to get the appropriate wavelength for the appropriate time of the day. So you can buy one light bulb, have it bright and blue during the day and then dim it to a warmer hue at night. But most companies they're going to buy the cheap one, right, and then that's going to be installed for the next 20 years because ideally, I guess energy-wise, it doesn't go out. So we've kind of got ourselves in this predicament now and you think about that indoor lighting as well as outdoor lighting. There's a lot of pushback now about streetlights. They're a little glaring, you might say, and that's strong in the blues.
William Davis, MD:It's an evolving conversation, isn't it?
Lynn Peeples:It is Same thing with headlights too. I know I personally struggle driving now with the bright LED headlights that seem to be very ubiquitous out there.
William Davis, MD:Now, if some listeners want to engage in the Lynn Peoples conversation, where would they do that?
Lynn Peeples:Yeah, you can find me at lynnpeoplescom L-Y-N-N-E-P-E-E-P-L-E-S. And then my book the Inner Clock is available anywhere you buy your books.
William Davis, MD:Great Lynn. Thank you very much for taking the time and sharing your insights.
Lynn Peeples:Yeah, thanks so much for having me.
