Lynne Peeples
Appearances
Fresh Air
Getting In Sync With Your Inner Clock
But in Alaska, we have, you know, we have this diverse population and he's, you know, he's finding that definitely overall, we've got increased rates of these things. Also, you know, schools there, the kids supremely affected by those short days in the winter where they're going to school in the dark and leaving in the dark.
Fresh Air
Getting In Sync With Your Inner Clock
And that might be one of the links between lower graduation rates in Alaska. Yeah.
Fresh Air
Getting In Sync With Your Inner Clock
Yeah, it's twofold. So when we spring forward or fall back, we are giving ourselves a dose of jet lag. But we're also, you know, we're keeping, we're locking the clock there. So when we spring forward, we're essentially stealing an hour of light from the morning, which is when we really want the light, right? And we're
Fresh Air
Getting In Sync With Your Inner Clock
Tagging that on to the end of the day when we our bodies really are looking for the dark and it's throwing us out of alignment from the sun. So the sun, I mean, before we had any kind of standard time around the world. locally the sun was generally at the highest point of overhead at noon, right? And if we shift that with daylight saving time, we're throwing that off.
Fresh Air
Getting In Sync With Your Inner Clock
So we're just, yeah, we're throwing our bodies out of alignment from the sun and those cues that, again, we're kind of telling our bodies what to do when, those messages are getting mixed up. And so there's some pretty creative research out there that has taken data from, from opposite sides of a time zone.
Fresh Air
Getting In Sync With Your Inner Clock
So if you look at the US and can kind of take folks that live on the western edge of a time zone and compare them to people who live on the eastern edge of a time zone and control for various factors, socioeconomic factors, for example. And scientists have found that as you move
Fresh Air
Getting In Sync With Your Inner Clock
From east to west, east being where the sun comes up earlier, west being where it comes up later, there are increasing rates of things like cancer, car accidents, wages decrease as you move from east to west. So really fascinating. It's kind of this natural experiment, right, that we're constantly living based on our time zones.
Fresh Air
Getting In Sync With Your Inner Clock
And so that's one way we might look at how daylight saving time could be affecting us overall. So again, we need light in the morning. We need darkness at night. And the popularity of daylight saving time is making it difficult to kind of
Fresh Air
Getting In Sync With Your Inner Clock
To get that message out, the scientists are really pushing policy towards considering permanent standard time, which, again, will keep us more in alignment with the sun. But most people, and I'm guilty of this too, have equated daylight saving time with those long days of summer. But there's really no way we can affect how many hours of daylight we have, right, whether that's summer or winter.
Fresh Air
Getting In Sync With Your Inner Clock
So it's just that allocation of the hour that we're really talking about.
Fresh Air
Getting In Sync With Your Inner Clock
Well, to some extent. I did have LED lights in this bunker. So kind of a non-traditional bunker. This was a souped-up former Cold War era bunker that somebody had purchased and set up as an Airbnb. And so he had LED lights throughout the bunker, which... I could tune.
Fresh Air
Getting In Sync With Your Inner Clock
As I've mentioned, we all tick a little differently. Those inner clocks in our bodies that tick at around 24 hours, for some of us, that means that they tick a little longer than 24 hours. And for some, they're faster, and it's a little under 24 hours to do its full circuit, so to speak. So because of that, there's times a day that we have a greater predilection for certain things.
Fresh Air
Getting In Sync With Your Inner Clock
And if we think about sleep-wake, that's where I think most of us experience these differences. So there's some of us that if we have a shorter circadian rhythm, we might more likely be early birds. It's easier for us to go to sleep early at night, and we might wake early.
Fresh Air
Getting In Sync With Your Inner Clock
And on the other end of the spectrum, there's the extreme night owls, where they may be at their peak late and be awake and alert into the night and then wanting to sleep in late in the morning. So it's both the speed at which our clocks tick as well as this alignment with light. So scientists are trying to understand that more now.
Fresh Air
Getting In Sync With Your Inner Clock
But how our body responds to light is also affecting how these clocks align with a 24-hour day. But there's not just early birds and night owls. There's a full spectrum that goes to pretty great extremes. Different genetics can predispose some people to truly function better overnight than during the day.
Fresh Air
Getting In Sync With Your Inner Clock
There's a normal curve, a continuous distribution, really, of chronotypes. It's really, we're all a little differently, just like the size of our feet, for example, or our height. There's a full spectrum. But we can kind of put people in buckets, as some scientists have done, to try to look at the differences.
Fresh Air
Getting In Sync With Your Inner Clock
Yeah, so our circadian rhythms do differ. Our chronotypes do differ across our lifespan. So when we're first born, as parents can attest, we don't really have a lot of rhythm. We're kind of eating and sleeping throughout the day and night. And then as we get a little older, young kids tend to be early risers. And that quickly changes when we reach adolescence.
Fresh Air
Getting In Sync With Your Inner Clock
And because I had learned that red light is the color that's least likely to affect our circadian rhythms, I set the entire bunker to a dim red light. So I could see. I had some light, but it was nothing like what we experience indoors or especially outdoors. So absolutely no daylight and then none of those blue wavelengths of light that are known to particularly affect our circadian rhythms.
Fresh Air
Getting In Sync With Your Inner Clock
So at that point, early teen years, our rhythms start to drift later. So it can be as much as two or three hours. Now, you know, a kid that used to rise and be alert and ready to go at 6 a.m., now it might be more like 9 a.m. And of course, that means it's harder for these kids to go to sleep at night. And then as we get older, this kind of balances out a little bit.
Fresh Air
Getting In Sync With Your Inner Clock
And then in our older years, on average, we tend to be maybe slightly early risers. But even perhaps more important, as the scientists are finding, as we get older, our circadian rhythms get blunted. They get weaker. So we do not have as profound of like a rise and fall in our rhythms. And that manifests in a weaker sleep-wake cycle. So we might be more prone to napping during the day.
Fresh Air
Getting In Sync With Your Inner Clock
You know, if you think about like the... The grandparents sitting in the chair kind of falling asleep during the day and then maybe struggling to sleep at night. That is always partially due to this circadian rhythm being weakened as we get older.
Fresh Air
Getting In Sync With Your Inner Clock
But because we're understanding that, we're also understanding how to potentially strengthen those rhythms in part through things like getting that extra contrast of light and dark throughout the day.
Fresh Air
Getting In Sync With Your Inner Clock
Yeah, we were kind of doing it backwards in the Western world. Yeah, the science suggests that it's late morning, early afternoon when our bodies tend to be most ready to handle those incoming calories. And late at night, things start shutting down. Our insulin levels drop. Our other hormones that our bodies release to help increase.
Fresh Air
Getting In Sync With Your Inner Clock
handle incoming calories and metabolize and break down fat, those things, those are weaker. And this is why scientists are suggesting we really should be eating in a narrower window of time and earlier in the day. One scientist talked about a sweet spot of like 10 hours during the day. If we can do that, if you could eat from, say, you know, 10 a.m. or 9 a.m.
Fresh Air
Getting In Sync With Your Inner Clock
to 7 p.m., that is really ideal to help Strengthen your circadian rhythms and potentially, based on some research that's coming out, that may improve your long-term health, your longevity, decrease your risk of developing chronic disease.
Fresh Air
Getting In Sync With Your Inner Clock
Right. So for the majority of us that are not extreme night owls, working at night is going contrary to what our body is primed to do. We're telling our body we need to be alert and awake and probably, you know, digesting food and doing all these things throughout the night when those parts of our physiology are essentially shut down. They're not ready for that.
Fresh Air
Getting In Sync With Your Inner Clock
So it's perhaps not a surprise, and scientists now have data to back this up, but that is throwing off our metabolism, which then drives up rates of obesity and diabetes.
Fresh Air
Getting In Sync With Your Inner Clock
And having those cues chronically coming in at the wrong times of day, at night versus daytime for most of us, just over the long term, it's the subtle kind of constant destruction that it's doing to our rhythms and our physiology that's counting on those rhythms to do its job.
Fresh Air
Getting In Sync With Your Inner Clock
Yeah, as we're understanding the impacts, we are understanding better what kinds of strategies shift workers could use to mitigate the impacts. And indeed, I mean, a lot depends on what kind of shift the worker is doing. And if they're trying to flip-flop, let's say they're doing a night shift for three days and then they want to leave.
Fresh Air
Getting In Sync With Your Inner Clock
on the same hours that their family does, for example, and so they flip to daytime. That's going to be a little different than somebody who's able to, say, shift their schedule seven days a week to night hours. And in that case, a strategy for, say, submariners or
Fresh Air
Getting In Sync With Your Inner Clock
people who are working in isolation where that's possible, is to do as you said, try to trick your body into thinking nighttime is daytime and that daytime is nighttime. You could do that with some lights now that have the potential to be really bright and really blue, a little more closer to mimicking the sun.
Fresh Air
Getting In Sync With Your Inner Clock
Then yeah, use blackout blinds while you're sleeping to create the illusion that it's nighttime. Really new research is pointing to the idea that even if you're working at night, You could try to consolidate the hours you're eating still to daylight hours because, again, I think a lot of the science is suggesting the consequences of shift work is due to that effect on our metabolism.
Fresh Air
Getting In Sync With Your Inner Clock
Yeah, I wanted to get a sense of, well, my personal rhythms. We all tick a little differently. And so I wasn't totally clear on just how my inner clocks ticked. You know, where was I on that spectrum of night owl to early bird? And then just what happens when we throw our clocks out of sync? I knew that from my research up until that point that cutting myself off from things
Fresh Air
Getting In Sync With Your Inner Clock
So if you can eliminate that factor, if you can still try to eat, you know, maybe it's right before you go into work. It's like, you know, maybe still light out in the evening. You eat your meal, go to work, and then try to hold off on eating again until you get out of work next day.
Fresh Air
Getting In Sync With Your Inner Clock
I mean, I think – I don't know that there's any answers on that yet. I think – For everybody, it absolutely makes sense to do the best you can in your current situation. So by working to keep robust circadian rhythms when you're back among the living, as you said, it certainly helps trying to get things back in alignment and keep it that way for the long term.
Fresh Air
Getting In Sync With Your Inner Clock
Because I did talk to one submariner who had a lot of trouble after landing. doing some crazy shifts on a submarine underwater for years. You know, he continued to have struggles with sleep, but he was trying to implement some more of these ideas of accessing those circadian cues to get his rhythms back in alignment. And that is definitely possible.
Fresh Air
Getting In Sync With Your Inner Clock
So men, on average, until about midlife, lean a little later. There's going to be a higher percentage of night owls among men than women. But as women's levels of estrogen drop, as they near menopause, for example, then their rhythms are shifting. The estrogen actually helps keep rhythms more robust and perhaps lean a little earlier. But as that estrogen is lost...
Fresh Air
Getting In Sync With Your Inner Clock
their rhythms become a little closer to men's rhythms. So there is that kind of shift over the course of our lives where there is a bit of a split, but perhaps we come together and maybe go to bed at closer to the same times at night.
Fresh Air
Getting In Sync With Your Inner Clock
Yeah, it's a really interesting question. And I did talk to one researcher who was really keyed in on the impacts of estrogen, menopause, and how things like the time-restricted eating could help. So we know that once a woman reaches menopause, those estrogen levels drop. we find that that's when chronic diseases start to rise.
Fresh Air
Getting In Sync With Your Inner Clock
So she's wondering if one of the mechanisms by which that's happening is through this dampening of her circadian rhythms.
Fresh Air
Getting In Sync With Your Inner Clock
So if that's the case, then if we're able to have that woman eating in a constricted period of time, getting light early in the day, darkness at night, feeding her those cues to help try to make up a little bit for that lost estrogen and try to help strengthen her rhythms, could that potentially improve her health long term and reduce the risk of these chronic diseases?
Fresh Air
Getting In Sync With Your Inner Clock
daylight, and from any other cue as to the time on the Earth's 24-hour clock, could throw those clocks out of sync with each other and out of sync with the sun. And we all experience that, at least acutely, when we travel internationally. We get jet lag, right? And so I wanted to get a sense both
Fresh Air
Getting In Sync With Your Inner Clock
I mean, it's an open question. The science gives pretty good rationale for that potentially being true, but the data will... be forthcoming probably in the next few years to see kind of how that actually plays out.
Fresh Air
Getting In Sync With Your Inner Clock
Yeah, there's really fascinating research coming out suggesting that very well might be the case. In fact, it might be the case that certain drugs that are used for mental health disorders like schizophrenia and depression might actually work by affecting the circadian clock.
Fresh Air
Getting In Sync With Your Inner Clock
And scientists are finding that night owls and patients with weak circadian rhythms tend to actually respond poorly to, for example, lithium. And he's also finding, or he's thinking one reason for that is that lithium lengthens and strengthens circadian rhythms. So for those that respond well, that's what's happening.
Fresh Air
Getting In Sync With Your Inner Clock
And that could potentially explain the benefit for lithium to some patients and the fact that it really doesn't work for other patients. And so this kind of line of research, thinking about this for various treatments, as well as the idea that
Fresh Air
Getting In Sync With Your Inner Clock
Focusing directly on helping a patient's circadian rhythms, again, through these techniques we're talking about, you know, getting more light during the day, darkness at night, eating patterns and such, that could potentially be a strong treatment itself. And then the idea comes up that, you know, this vicious spiral that happens with a lot of mental health disorders where...
Fresh Air
Getting In Sync With Your Inner Clock
Somebody is depressed, for example, and they're indoors during the day. Well, on average, we all spend a majority of our days indoors, at least 90%. But being indoors and missing that morning light then sets them up to more likely stay awake later at night. And then that's going to set them up to sleep in the next day. And overall, that's going to weaken their rhythms.
Fresh Air
Getting In Sync With Your Inner Clock
And if there's a link between that and the disorder itself, it creates the snowball effect that some of the science is pointing to potentially a way out.
Fresh Air
Getting In Sync With Your Inner Clock
Right. So there is mounting data that is finding correlations between circadian disruption as well as exposure to light at night and cancer. So the jury is still out on really, you know, directly linking the two. But the science is pretty clear that as we disrupt our rhythms and we disrupt our immune system and, again, our ability to metabolize food at the right times of day and all these things,
Fresh Air
Getting In Sync With Your Inner Clock
It's not a shock to scientists that there could be ramifications for how that could propel the development of cancer and heart disease, other cardiometabolic disorders, and then in the long term, potentially dementia. The hypothesis at this point is it's probably bidirectional when we think about that, because we know that
Fresh Air
Getting In Sync With Your Inner Clock
patient with dementia, the part of the brain that's affected by that is also affecting the circadian clock. But we also have evidence to suggest that disrupted circadian clock potentially could lead to an increased rate of development of neurodegeneration.
Fresh Air
Getting In Sync With Your Inner Clock
qualitatively with how I felt as well as quantitatively what that kind of looked like and how those paired up. So I decked myself out with a whole bunch of different sensors. So I was measuring my temperature of various body parts. I was measuring my heart rate. I had a glucose monitor. I was checking my light exposure as well. And all that data
Fresh Air
Getting In Sync With Your Inner Clock
So they think it could be going in both directions and leading to this spiral that, unfortunately, some people reach in those latter decades of life. But that, again, is also pointing to, if we understand that, maybe that could help us find new treatments or, again, help
Fresh Air
Getting In Sync With Your Inner Clock
certain people, you know, as we get older, try to access more of those cues, more of that circadian hygiene that helps their rhythms stay robust. And could that, again, delay the onset of these diseases? Or if somebody has that disease, could having those stronger rhythms alleviate some of the symptoms and slow down the progression of that disease?
Fresh Air
Getting In Sync With Your Inner Clock
These are open questions, but a lot of promising research that's suggesting that there is a lot of potential here.
Fresh Air
Getting In Sync With Your Inner Clock
I had uploaded, but I wasn't looking at it until after the experiment when I had scientists help me kind of tease apart. How were these various clocks in my body ticking throughout those 10 days? How did they change? How did they drift both apart from the sun and apart from each other?
Fresh Air
Getting In Sync With Your Inner Clock
Oh, yeah. About halfway through is when I really started to feel it. And halfway is very subjective, right? I had no sense of time. I had no access to clocks. But about halfway through, yeah, during the day, I could feel my temperature rise and fall in seemingly unnatural ways. Middle of the day, I'd be kind of hot and sweaty. And then I'd get cold. I'd feel... kind of this brain fog.
Fresh Air
Getting In Sync With Your Inner Clock
At certain times, I found myself really clumsy. While I was down there, I was teaching myself to juggle and play harmonica. And in this particular day, about I think day seven or eight, I was just dropping everything and super uncoordinated. And then, yeah, feeling hungry and tired at all hours of the day. So it was pretty clear based on how I felt that my clocks weren't quite ticking right.
Fresh Air
Getting In Sync With Your Inner Clock
Yeah, yeah, right. I was, well, kind of proud of myself looking at the data. Like, about a day in, I was consistently making guesses of the time into a voice recorder, which I could then check back later with the actual time. And a day or so in, I was really close. I was living about 24-hour days. But over time, that drift accumulated and jumped a bit.
Fresh Air
Getting In Sync With Your Inner Clock
So it was a couple of days before the end of the experiment when the data showed that I had completely flipped. I was kind of being silly one night and decided to have breakfast for dinner. I was making blueberry pancakes. And it turns out that while I was eating them at what I thought was, you know, evening time, it was actually the morning. I had completely flipped my clocks at that point.
Fresh Air
Getting In Sync With Your Inner Clock
Yeah. So the scientists helped me see that these various inner clocks in my body had fallen out of coordination about midway through. So about that same time that I was feeling just really out of whack, you know, uncoordinated and a little loopy and, you know, mood swings. That was when the data showed that my heart rate rhythm and my temperature rhythms were no longer coordinated.
Fresh Air
Getting In Sync With Your Inner Clock
And also when I was becoming more and more uncoordinated with the sun. So it was really it was it was fascinating to know that why, again, my kind of qualitative or how I was feeling those notes that I had made could really be linked pretty directly to to that data of what was happening inside my body.
Fresh Air
Getting In Sync With Your Inner Clock
Right. For a long time, I too thought every time I heard circadian rhythms, I just thought sleep-wake, sleep-wake cycle. But in fact, we have trillions of tiny clocks in our bodies, really, when you think about it. Nearly every cell in your body has a clock.
Fresh Air
Getting In Sync With Your Inner Clock
And these clocks evolved to coordinate with each other and with the sun to help our bodies be primed to do the right things at the right time.
Fresh Air
Getting In Sync With Your Inner Clock
And sure, one of those things is to go to bed and sleep at the right time and wake at an optimal time based on our pirouetting planet and the light and dark cycle and what, you know, we evolved, the times we evolved to be most alert and awake and take advantage of the light of the day. And circa in circadian means about or around. So that really tells us.
Fresh Air
Getting In Sync With Your Inner Clock
So our inner clocks did evolve to be to tick at around 24 hours, but they're not precise timekeepers. So we need that regular calibration from the environment, from the Earth's 24-hour cycle to keep them coordinated with each other. and with the sun so that they are primed to do those right things at the right times. And that is, again, so that's sleep-wake.
Fresh Air
Getting In Sync With Your Inner Clock
That's also digest food and metabolize food. It's perhaps the time that we're, you know, strongest and fastest to perhaps sprint away from our predator, if we're thinking evolutionarily, or the time that we should be set up our defenses stronger against invading pathogens. So our body can do all these things at all times across the entire day.
Fresh Air
Getting In Sync With Your Inner Clock
So we've sort of evolved with an allocation of resources across the clock.
Fresh Air
Getting In Sync With Your Inner Clock
Yeah, I can speak from experience. I mean, I think a good part of the motivation for me to write this book, I mean, somewhat subconsciously, is having grown up in Washington. Growing up with really what I felt was sort of this almost bipolar feeling throughout the year. You know, summer, it's so much light, so long throughout the day.
Fresh Air
Getting In Sync With Your Inner Clock
In the wintertime, I mean, the hours of daylight are really shrunk down. And I felt that effect. I felt, you know, in the wintertime, just... more depressed and down and less alert. And especially going to school in high school, it was before 730 that the first bell rang. And so I wouldn't see daylight before I got to school.
Fresh Air
Getting In Sync With Your Inner Clock
And then after school, you know, maybe I'd be at basketball practice and come out in the dark as well. So absolutely, we need daylight. Our clocks and this coordination of our entire physiology really counts on those inputs of of light and dark to tell the body that it's day and night and coordinate those activities.
Fresh Air
Getting In Sync With Your Inner Clock
And when we don't get daylight, when we don't get those photons to help calibrate those clocks, then things go awry. And that affects our mental health and our physical health.
Fresh Air
Getting In Sync With Your Inner Clock
The science suggests that light across the whole day is crucial, but in particular morning light. Again, the science is evolving. There's always new data points here that maybe slightly tweak the picture. But it's pretty clear that during the daytime, especially in the early hours, getting daylight will help recalibrate our rhythms.
Fresh Air
Getting In Sync With Your Inner Clock
And then throughout the day, the accumulation of getting those photons from the full spectrum that the sun offers, in particular those blue wavelengths of light that we get from the sun, will help align our rhythms as well as help make them more robust. So we create really this kind of stronger amplitude of our rhythms throughout the day, which is also crucial.
Fresh Air
Getting In Sync With Your Inner Clock
So yes, and then at night, again, to keep that contrast, to make the body understand that this was day and this is night when we're supposed to wind down for sleep, That's when we need the lights down and not blasting our overhead lights in our homes, for example, or putting our face in front of screens. So, yeah, it's all about that contrast.
Fresh Air
Getting In Sync With Your Inner Clock
Yeah, it depends who you ask. In general, screens do emit light and a lot of blue light. But sometimes when we talk about screens, I think we overlook the bigger picture. I mean, if we're sitting in a living room that has super bright LED overhead lights blasting and maybe a floor lamp beaming it down on you too, that... is at least equally as important as the screen in front of you.
Fresh Air
Getting In Sync With Your Inner Clock
And there's also tools now with our iPhones and our computer screens to kind of suck out some of that blue light so that it doesn't have quite the same effect on our circadian rhythms as well as to dim it. So I think there are tools to use. I think in general, there's probably a good rule of thumb to try to tone down our use of screens at night. But There's a balance to be had as well.
Fresh Air
Getting In Sync With Your Inner Clock
I think it's not necessarily that we need to completely cut them out. But within a few hours of bed, trying to trim down how much of those photons, particularly blue ones, that are making their way into our eyes.
Fresh Air
Getting In Sync With Your Inner Clock
Yes. Asking for a friend. Or walking to the bathroom and flipping on the lights. That's another huge one because our body is not anticipating that light at night. So it has a super powerful effect on us. on our circadian rhythms and our alertness. So it makes it a lot harder to go back to sleep. So I have now, I put a nightlight in my bathroom that is dimmable and very warm colored.
Fresh Air
Getting In Sync With Your Inner Clock
So I will not be flipping on that light at night anymore.
Fresh Air
Getting In Sync With Your Inner Clock
Yeah. On my way actually to Denali for this trip, I stopped in Fairbanks to meet with a sleep doctor there. I mean, he was telling me stories about his patients and how he'd have an increase in patients during certain times of year, particularly during these transition times. Because as the days rapidly shorten or rapidly lengthen,
Fresh Air
Getting In Sync With Your Inner Clock
He was finding a lot of patients coming in with physical and mental issues and lots of struggles with sleep, obviously. And he thinks that it's really confusing our clocks. As those days shorten a lot more rapidly than, say, where we evolved at the equator, where we had 12 hours of light and 12 hours of dark, that just throws the body off.
Fresh Air
Getting In Sync With Your Inner Clock
And there's been research that shows that in some of these high northern latitudes, There are certain populations of people who maybe migrated there at earlier points in history. And so their genetics may have evolved a bit more to compensate and to adapt to that changing light environment. And they might be less prone to things like SADD. During the winter, for example.