How Light Disrupts Our Sleep | Prof. Philippa Gander

Our understanding of the body's internal clocks is rapidly evolving, with new research shedding light on the powerful effects of circadian rhythms. From the way artificial light disrupts our sleep patterns to how animals’ natural cycles offer valuable insights into human health, the science is undeniable. 

Dr. Philippa Gander, a leading expert in sleep and circadian rhythms and author of Life in Sync: The Science of Internal Clocks and How We’re Disrupting Them explains how these disruptions impact not just humans but entire ecosystems, including marine life. 

Her groundbreaking work also reveals the profound effects of light pollution, offering fresh perspectives on how we can better align our lives with our biological clocks. In this conversation with Peter Bowes, Gander also highlights practical ways we can make adjustments to better sync our lives with nature’s rhythms for improved health and well-being.

Photo credit: Lucia Zanmonti

-----

This podcast is supported by affiliate arrangements with a select number of companies. We have arranged discounts on certain products and receive a small commission on sales. The income helps to cover production costs and ensures that our interviews remain free for all to listen. 

Visit our SHOP for more details: 
https://healthspan-media.com/live-long-podcast/shop/

Time-line

Mitopure (a highly pure form of Urolithin A) boosts the health of our mitochondria – the battery packs of our cells – and improves muscle strength. Time-line is offering LLAMA listeners a 10% discount on its range of products – Mitopure powders, softgels & skin creams.  Use the code LLAMA at checkout
-

Fit, Healthy & Happy Podcast
Welcome to the Fit, Healthy and Happy Podcast hosted by Josh and Kyle from Colossus...

Listen on: Apple Podcasts   Spotify

EnergyBits algae snacks
A microscopic form of life that could help us age better. Use code LLAMA for a 20 percent discount

SiPhox Health home blood testing
Measure 17 critical blood biomarkers from home. Get a 20% discount with code LLAMA

PartiQlar supplements
Enhance your wellness journey with pure single ingredients. 15% DISCOUNT - use code: MASTERAGING15

Disclaimer: This post contains affiliate links. If you make a purchase, I may receive a commission at no extra cost to you.

Chapters

• 19:09 [Ad] Fit, Healthy & Happy Podcast
• 19:57 (Cont.) How Light Disrupts Our Sleep | Prof. Philippa Gander

Transcript

Philippa Gander: 0:24

We've taken on a totally false notion that sleep is something you can trade off for more waking time, more busy time when you're waking life. And the evidence is absolutely, powerfully clear that that is not the case.

Peter Bowes: 0:38

I remember a few years ago, actually a few decades when 24 hour living first caught on. Now, of course, we're all living 24 hours a day. And for some professions, night shifts have long been an essential reality. But the novelty of being able to pop into a convenience store or the gym, or grab fast food in the middle of the night really took off in the 1970s. Early 80s. It was celebrated as a sign of changing work patterns and an accelerating pace of life. But have we been paying a price for that convenience with our health? Hello again. Welcome to the Live Long podcast. I'm Peter Bowes. This is where we explore the science and stories behind Human longevity. Philippa Gander is professor emeritus and founder of the Sleep Wake Research Center at Massey University in New Zealand.

Her new book is Life in Sync: 1:34

The Science of Internal Clocks and How We're Disrupting Them. Philippa, it's good to talk to you.

Philippa Gander: 1:43

Thank you, Peter, thanks for the invitation to be here.

Peter Bowes: 1:46

And thank you for getting up relatively early in the morning. You're in New Zealand. I'm in Los Angeles just early afternoon here, and I just wonder if that is part of the problem these days. That communication is so easy over video links, and we're all talking to each other at various times of the day.

Philippa Gander: 2:02

Well, you're in luck because I'm a morning person, so it hasn't bothered me in the slightest. But yes, it is an issue that being available 24 hours a day for doing meetings. I once was organizing a group of people globally, writing a scientific paper for a big meeting, and it was absolutely impossible because for me it was 1130 at night by the time I could get everybody else in.

Peter Bowes: 2:25

Actually, like you. I'm a morning person as well, so I get it to some extent how we're all different. I think some of us are born morning people, some of us are night owls. And that's very obvious by the lifestyles that we lead. But let's start by talking a little bit about your work. And I mentioned the Sleep Wake Research Center. What do you do there?

Philippa Gander: 2:47

Well, the essence of of the science that we do, and particularly of my science, is how life on earth is actually adapted to the cycles of the planet, the environmental cycles. And so mostly we're working with the circadian rhythms, which, are rhythms that are generated inside your body by a genetically driven clock, and they are set up to, adapt you to the changes that should be happening regularly in your life with the day night cycle. And what's extraordinary about this is that, this internal clock system that we have, the same clock genes, are found in every kind of species on the planet. Everything from bacteria, algae, fungi, plants, animals, us have circadian clock genes. And what you have from that is that you have an internal mechanism which is driven by genes in the cell. in most of the cells in your body, actually, for us, and those genes produce a daily cycle in clock proteins, the concentration goes up and down, up and down, up and down, and the way they produce them. And that actually influences everything else going on in the cell. And so you've got this happening in literally trillions of cells in your body. And we, we sort of tend to overlook the fact that actually we're programed to be rhythmic, but life on Earth is generally speaking. And so we're not unique in this. What is unique, is that we're the first species that's ever tried to override it. And we didn't realize when we started this that it's actually genetically programed into us. So, it's quite a complex structure, as you can imagine, because these clock genes are interacting with different things in your heart and your lungs and your in your digestive system. and so you've got different rhythms going on in your different organs.

Peter Bowes: 4:47

And these clock genes are triggered by multiple factors. Clearly genetics is playing a role. But environmental factors external factors as well.

Philippa Gander: 4:56

Yeah. So you've got all these different things going on in your body, in different organs, in your body, in different tissues. and to keep that all marching together, we talk about it like a symphony orchestra. If you don't have the conductor up the front, you don't get music, you get horrible noise. We have that effectively. We have a master circadian clock in the brain, quite well known now how it is and where it works down to the cellular level, and what it's doing is keeping it's got two jobs. One of them is keeping everything in your body synchronized, so all your rhythms are running in step with each other. and it does that by manipulating two hormones. We call them messenger hormones, which are melatonin and cortisol. We could go a long way on talking about melatonin. And it also does it through having neural connections to other parts of the brain and the body. So you've got this master clock there. But his other job, apart from holding everything together and sync, is that it's designed to keep you in step with the day night cycle. And it actually has its own blue light sensitivity separate from vision. It's got blue light sensitive cells, which are actually tracking blue light even through your closed eyelids. And blue light has different effects depending on when in the cycle you see it. So if you get blue light in the morning, then that will slow your speed. Your circadian pacemaker up, your master clock up. So, you know, if you've got most of us have got a natural day night cycle, which is a bit longer than 24 hours and blue light originally, sunlight in the morning will pull that cycle up, shorten cycle up to 24 for you. Few people have a cycle which is long, is shorter than 24 hours, and they've got to stretch theirs out. And what happens? And what is one of the big factors which is affecting us now is that light blue light in the evening delays your circadian master clock. Whoops. So now we've got all these blue light technologies that we look at before bedtime. And that makes it much harder to go to sleep and harder to wake up in the morning, because actually, your master clock is switching on sleep promoting centers at some time of the day and switching on wake promoting centers at the other time of the day. And we're sliding that around by our exposures to blue light.

Peter Bowes: 7:14

So why is it that some of us aren't? I mentioned some of us are clearly Morning people. We just feel better. We perform better. We're more awake and functional in the morning. Other people feel that late at night. Some writers prefer writing after midnight because that's when they do their best work. What makes us different is this this is the genetic factor that are we born like this?

Philippa Gander: 7:36

There's two parts to that. That was one part is genetic. And there are families, for example, where there are extreme evening types and extreme morning types and other families. And at the extremes there are different versions, different polymorphisms of the clock genes, slight differences in the genes. But it's not only about the genetics, it's also about your light exposure. So, you know, if you are a person who is a morning type and you get a lot of morning light or you get up particularly early, you're adding to that effect. Whereas if you're an evening type and you stay up late and you watch a lot of blue light, you're delaying your clock even further. So you get later and later. So it's a mixture of your light exposures and your genetics.

Peter Bowes: 8:20

Is it possible to manipulate our behavior to. Let's say we are. We feel as if we're a night owl, that we perform better. But can we change to become a morning person? Because that's the the kind of lifestyle that maybe because of our work or our family situation, that really suits us best, can we become the opposite to what we feel?

Philippa Gander: 8:42

I think the evidence is fairly strong that whether we can or not, we don't. And there's a phenomenon that's becoming become known as social jetlag. And that is the difference between your the timing and amount of sleep you get when you've got a scheduled day, like a work day, and the amount of sleep you get on an unscheduled day when you can just go to bed when you feel like and wake up when you want to. And what's interesting is that, there've been a number of studies. There've been some really interesting studies done on in New Zealand, but a few, there's one longitudinal study in New Zealand, where they found that people who by the time they've been tracking them from birth and by the time they're 38, people who have bigger social jet lag, which is a bigger difference between their scheduled days and their unscheduled days are more likely, for example, to have, to become obese, to have symptoms of cardiovascular disease, heading, setting up. So it looks as though, whether you could actually if you systematically changed all of your timing to do that, you might be all right. But we don't think so. It's not something that you can sort of basically override with any combination of external factors. It's something which is built in. And when you do it systematically one way backwards and forwards, backwards and forwards with social jet lag, it does have health effects long term.

Peter Bowes: 10:04

So let's examine and you look into this in your book. Let's examine how things have changed over the past few decades. And I started by talking about this, this so-called 24 hour lifestyle. I remember that time, 70s, 80s people actually got quite excited by the fact that we we could do things around the clock.

But honestly, looking back, I've never actually been to the gym at 3: 10:21

00 in the morning and never had the desire to, and very rarely walked into a convenience store at that time of day either. But how did it change us? What effect did it have on us as human beings as we maybe it was forced upon us to some extent, but we began to evolve to to this idea that we could do anything at any time of day.

Philippa Gander: 10:45

I think the biggest challenge from the point of view of our, of our health and safety and wellbeing is that it's restricted our sleep. And I think that we've taken on a totally false notion that sleep is something you can trade off for more waking time, more busy time in your waking life. And and the evidence is absolutely, powerfully clear that that is not the case. And so I think that, that's probably the biggest price we've paid. And the real challenge is that if you don't get enough good quality sleep on a regular basis in the short term, that will impair all of your waking function. So your physical and mental functioning, your mood, a whole lot of things will change. Everything about your waking function will change. And the thing to know about that is that if you don't get enough sleep night after night, the effects build up. We call it building a sleep debt. As you get sleepier we've sort of put out, we say if we're hungry, we need to eat, we're thirsty, we need a drink. If we're sleepy, you're lazy. You're you're not properly motivated. You're not part of the modern world. Not true. It's a brain signal that you're not sleeping enough. And brain needs sleep for you to function fully. And so as the effects build up, the other thing, which is really a bit insidious, is that you get less and less able to judge actually how you're functioning. So the more you build up. So say you need eight hours a night and Monday to Friday you have to get up two hours early to go to work by Friday or ten hours in debt. And you will be functioning much worse than you were on Monday. But you won't necessarily know that. And the other thing that happens is that you will get to the point where your brain will shut you down and fall asleep. Even if you're in a life threatening situation like driving a car. You can't force your brain to stay awake beyond a certain point. And what it does at the beginning of sleep is it disengages from the environment. It stops taking in all the information from the environment. So suddenly you're going along at 100Ks and you're just not aware of what's happening around you. And, unfortunately, I've been an expert witness in a great number of, accidents that have caused death with people falling asleep at the wheel. So it really is important. You know what we've sacrificed, I think. And there is evidence that the population level in a number of countries that we are sleeping less than we were before, all of these 24 hour changes sort of became fashionable. And to some extent, I think they're driven. You can get very political about this very quickly, but I think they're driven by the model of, you know, greater productivity and growth in some respects. There is a limit to what we can do, and we need proper recovery and recuperation on a regular basis. And that's sleep.

Peter Bowes: 13:42

Yeah. And I think we are increasingly in a large part because of the kind of research you've been doing, beginning to understand that you hear people say, oh, I'll, I'll sleep when I'm dead. Well, it's such a ridiculous statement.

Philippa Gander: 13:55

That's the honest scientific answer. You'll be dead quicker.

Peter Bowes: 13:58

Yeah, exactly. And what you've just been saying illustrates why, at least for me, sleep is right at the top of that health pyramid. It is that if sleep isn't right, your diet tends to be not as good as it should be, because you maybe you you seek out more sugar to give you some energy.

Philippa Gander: 14:15

You're absolutely right. There's been a number of experiments that have looked at that. And if you sleep, restrict people in the lab even for 1 or 2 nights. What it does is it changes the hormones that control your appetite. So if you're sleep deprived, you make more ghrelin, which is what makes you hungry, and you make less leptin, which is what makes you feel full. And in the lab, a lot of people want high fat, high carb. So that's your brain is saying, you know, you're not getting enough sleep. Well, you need to, you know. And so you need more energy and you eat more. It's that is quite well understood.

Peter Bowes: 14:51

And equally with exercise. And it's kind of obvious, isn't it, that if you're sleepy, you're tired, you're less inclined to exercise, which is, in the bigger picture, ultimately crucially important in terms of our everyday health and potential longevity.

Philippa Gander: 15:06

There's some interesting things around exercise and eating. And it's a bit complicated. But when you're thinking about the, you know, the circadian timing system in the body with the master clock in the brain. the master clock is the main synchronizer, and it's using blue light to try and keep you in step. And so it's talking to all those other organs to keep you everything running together. But your digestive organs are also sensitive to when you eat. That can shift them in their cycle. And so now if you're eating a hamburger in the middle of the night, you've got your master clock telling your digestive system that it's night time outside, you should be asleep and fasting. But suddenly you've got all this food coming in, and that's a signal to your digestive system that it should be active in doing something. And so those are conflicting signals to your digestive system. And what we can see in animal studies at least, is that right down to the cellular level, you can see that that's mucking up the metabolism of your cells. And and with exercise, interestingly enough, there's a similar story. So your skeletal muscles, for example, are getting their input from your master clock in the brain, but they also get they get input, they get a shifting signal from when you exercise. And so again, you can have conflicting signals between what you're doing and what your master clock is telling your, your muscles you should be doing. And so the two are fighting each other, if you like, at the level of the individual cells. And that is not healthy.

Peter Bowes: 16:39

And therein lies the the huge problem that people who are forced to work night shifts face all of these conflicts. I've occasionally had to work through the night, not regularly, but occasionally. And I know what it's like, and it's really tough. But for people who have to do it day in, day out, it poses a real dilemma, doesn't it? In terms of how they manage their lifestyle.

Philippa Gander: 17:00

It really does. And I honestly think that we need to have a much bigger debate about why and when we do night work. And certainly a lot of my work has been focused on how do we do it better if we have to do it? and the challenge there is that, there's an enormous body of literature that says it's not good for you. There's been regular reviews done by, well, every 20 years or so, by the, the International Agency for Research on Cancer, for example, which is the UN body that looks at the impact of work patterns and safe work, amongst other things. And they, have decided about 20% of the in their latest survey, which was 2019, they bring all the world experts together and they get all the data they can. 2019 it's estimated that about 20% of the global workforce does not work. What is interesting is they have also found that it is a probable carcinogen, nightwork, and that's been on the cards for a while. They look at three kinds of evidence. One is how much evidence is there is human in humans. And that's a bit hard to find because we have different combinations of risk factors for developing cancers. And we have they change over time. But you can cause cancer in experimental experimental animals by forcing them to work a schedule which runs against what their circadian master clock is telling them to do. You can actually produce cancers, and you can see at the cellular level why that happens. So I think although they've said it's probable because we don't have a lot of data in humans, I think my perspective from the experimental data with animals is pretty clear. And then that really becomes a major factor that we have to look at at a societal level. But it's also one of the reasons that I wrote the book, because we do understand a lot more about how we could do this better.

Peter Bowes: 19:47

Yeah, exactly. And that was going to be my next question that we have all this understanding, this continuous research and a greater understanding of the harm that particularly working night shifts is potentially going to do us. But in terms of acknowledging that nurses and doctors and train drivers and all sorts of different professions have to work unusual hours, what do we understand about the science that can actually help people in that position to just manage their lives a little bit better?

Philippa Gander: 20:17

there are a few examples in the book, but just some of them, when you think about the impact, how much of your normal sleep time has been taken away by having to be at work? Because it's not only that you're going to be working when you're less functional because you're in the wrong part of your body clock cycle. It's also that you're going to be sleeping in the wrong part of your cycle, and you can't get as good restorative sleep. And so we look at, how the sleep debt is building a better across a roster. And that's really the timing, not only the length. We've always looked at the length of shifts, but the timing of the shifts is really critical as well. And then, what you then need to look at is how often does somebody get the chance to get at least two full nights off in a row to get recovery sleep? We don't really know the full answer because in the lab, if you sleep, restrict people or make them do night work, and then you give them time to sleep, the internal structure of their sleep goes back to normal after two full nights. And we're talking about going to bed when you're tired and waking up spontaneously, not with the alarm clock. So two full nights of sleep, but at least in lab studies, that doesn't necessarily restore all your waking function. You might need more than that. And we don't know actually how long that takes. And the other thing that's clear from lab studies is that some people are a lot more affected than others, and we don't know why. But if you look at rosters differently, you look at them and you say, okay, how much sleep time is this particular night shift going to be taking up? Could I move it a few hours earlier or later? You know, would that help? And then how often are these people getting a real chance to recover? But of course, the other issue there is not just the work patterns, it's that most of society and people's kids and their friends and family are day active. And so there's a lot of competing time demands when you're doing night work. And that's another part of the problem. And I think we really have to I mean, there have been a number of studies where, for example, just going back to the cancer issue, in what was it, 2007, the International Agency for Research on Cancer came up with much less data, came up with conclusion that night work was probably carcinogenic. And since 2009, Denmark has actually, reimbursed, breast cancer in women doing night work if they've done more than 20 years of night work and they don't have other risk factors. So it is a workplace illness, which means that it's, compensated through funding that's provided by the employers. We have a similar scheme in New Zealand. you know, so it's regarded as something that is caused by your work and therefore has to be compensated. So there's a lot of work to do in that area, I think. but it's also a lot of my work has actually been with international airline pilots because they do shift work and jet lag at the same time. and there are some solutions that work a lot better in that environment. but there isn't actually any magic bullet apart from making sure that people get enough recovery time to get their sleep fully recovered and get their functioning back to normal. and that's, you know, a reality that we live with, but I think we really have to be working on.

Peter Bowes: 23:27

Yeah. And I think the impact on an airline pilot is something we can all appreciate if we travel regularly and know just how we feel as a passenger, just on that one flight, how disruptive it must be, as you say, crossing time zones, working long hours and often during the night time.

Philippa Gander: 23:44

And the way to work this out is to, I'm a very strong believer in the fact that, I can bring the science to the table, but we also need the input of the people who are doing the job, because they're the people who are most aware of the risks and the challenges. And then we need the people who are sort of representing the organization and know what the limitations and requirements are for the bigger picture for the organization. And then we have the regulators who are, you know, different government agencies that are limiting these things and providing oversight. And so I really think that it's, we need to bring all of that expertise together. And I think I've had a lot of fun doing that in a lot of different areas all over the world, actually, because as the scientist, I come neutral, and I can provide, you know, a neutral ground so that people can kind of look at things a little differently and we can put all of our perspectives together. And I think we can come up with better solutions. I think we've demonstrated that we can.

Peter Bowes: 24:40

Let me ask you this. What can we learn from animals, from the pets in our lives, the dogs and the cats? Obviously free from the stresses of being a human being and having to go to work. But we all observe how our animals spend their time when they sleep, how they wake up, how they stretch, when they wake up, little things like that. What could we learn from their lifestyles, if indeed there is something about their lifestyles that is relevant to us?

Philippa Gander: 25:09

Well, I think the the well loved ones have a very predictable lifestyle and everything is provided that they need. And maybe that's something that's a bit hard for humans to attain on a regular basis, I don't know. We don't have a we don't have a nice person looking after us. you can often see one. One of the things that I find fascinating is that if you're watching your pet sleep, you can occasionally see their eyes darting around under their eyelids. And that's when they're actively dreaming. That's what's called rapid eye movement sleep, which is quite cool. The other thing is I did some studies way back with cats. I've been a big cat fan all my life, but I did actually do some studies with cats way back, and they are what we call. Well, the ones that I looked at. That was in Boston. Are crepuscular. They're active at dawn and dusk, and they sleep during the day and they sleep at night. So they have split sleep. and, you know, so there are different patterns in different animals depending on what their environmental demands are, you know, what would have worked best for them over environmental time, over evolutionary time. and then, you know, finding a nice, friendly person to look after you is probably a fairly good adaptation, too.

Peter Bowes: 26:17

Yeah. I'm really struck just by observing my dogs that the circadian rhythms that they live by, how precise they seem to be day in, day out in terms of. And my dog's are very lively dogs. But when it comes time to sleep, they sleep. And if I get up early in the morning too early, they'll look at me and go back to sleep. They're not ready to get up yet, and they seem to be have this instinct to judge when to do things during the day.

Philippa Gander: 26:43

I don't know. My sister has a springer spaniel. That's the opposite. She wants to get up very early in the morning and disturbs the family.

Peter Bowes: 26:50

Oh, well, there you go. Maybe I have no theory on this. Let me ask you during the. Clearly, this has been your life's work. But as you focused on this particular book, did you learn something new from your research that maybe hadn't occurred to you before?

Philippa Gander: 27:06

I certainly did. I certainly did. and the thing that and it sort of become a bit of a, yeah, a bit of a passion for me now. The thing that I learned about that I hadn't really thought about is what we're doing with artificial light at night. And so we said right at the beginning that, you know, all species are have these circadian clock genes and one of the most important synchronizers. And there are rhythms of different lengths. There's not only circadian rhythms, but, you know, there are rhythms that are associated with the cycles of the moon the changes in the phases of the moon. And there are rhythms, of course, that are associated internal clocks that are associated with the rhythms of the moon and the tides. And there are internal clocks that are associated with the seasonal changes in day length and the changes across the year. And so what is amazing is that for many, many species and for all those different kinds of rhythms, light at night, artificial light at night is taking away the environmental synchronizer that they need to stay in step. None of them match exactly their environmental cycles. They need the external signals and we're masking those. So if you think about light at night, well, obviously it's masking the day night cycle for us, but it's also masking the phases of the moon. And a lot of marine species need the phases of the moon for synchronizing, breeding and things like that. and it is also changing a lot of plants, but also probably us and a lot of other species use the seasonal changes in day length as a way of our bodies and brains preparing for the different timing of the seasons and the different availability of food and the changing temperature and all those things. And so we're really masking the most, probably the most important cues for all these internal body clocks that we've got. And there are quite a few examples now that have been studied. one of the first that came to people's attention was actually trees, deciduous trees, and deciduous trees next to street lights don't lose their leaves. they lose them later. And so what it means is that they're not physiologically prepared for winter, and they're more likely to get frost damage. But there are quite a few studies now that have looked at this in great detail. And, so I think that, you know, our use of artificial light, again, it's another area where we could do it differently. What we've tended to do is we've gone from much sort of warmer red light sources, candles, tungsten bulbs to much brighter white containing a lot of blue light with LEDs. And that's one of the reasons that the light at night is expanding so fast is an incredible statistic that I only learned last year. in the year 2023 alone, globally, light at night increased by 10% in one year. And NASA's been doing, you know, composite photos of this for years. And it's incredible. When you look at how rapidly light is increasing. It's always been high along the western U.S., Europe, but now in Asia, increasing very, very rapidly the Indian subcontinent and throughout Asia with industrialization 24/7

Peter Bowes: 30:27

And that is there a reason for that big jump?

Philippa Gander: 30:30

the one of the suggestions is that it's, LEDs because LEDs use much less energy so you can afford to light things up. And for some reason we went to a lot of blue in LEDs, but it has a number of effects. Light at night. It is making it much harder to do any good visual astronomy, because blue light scatters in the atmosphere and you don't get clear vision. it also is, as I said, affecting a number of species. And there's a fascinating series of studies that's been going on for some years now in the Netherlands, where they looked at this idea, well, you know, bright light and towns. But then there's lots of other things in towns that might be affecting plants and animals. So they set aside for forest edge areas, and one of them has normal day night cycles, and the others one has green, one has red, and one has white light coming on a day at sunrise and going off at sunset. So you've got the same timing of light, but you've got different colors of light. And what you can see is really extraordinary changes, particularly in the white light and the green light, which is a mixture of blue and yellow, of course, and things like there are two species of bats and they are in the blue, in the white light and in the green light. There are a lot more insects active at night. A lot of insects are attracted to light. So one lot of bats are very good fliers and they're getting doing really well. They're eating all these insects and reproducing massively. And the other ones are not such good fliers. And so they don't necessarily come into the light, and they're more likely to get picked off by owls and other things. So you see there's starts to layer this happens then this happens, then this happens, then this happens. And the one, which one which I find particularly challenging. And the evidence is not all in, but it's pretty scary is that, the biggest movement of biomass on the planet every day as the animal plankton, the zooplankton coming up in the oceans to feed on the plant plankton. The phytoplankton, phytoplankton are on the surface and they are plants, so they are capturing carbon dioxide from the atmosphere. When they get eaten by the animal plankton, they take that cow up and down into the water and they die and they poop and they get eaten by other things. So they're actually bringing down a lot of carbon every day. And there is some evidence that those animal plankton won't come up when there's light at night. They are light averse. They don't come up, you know, around a very highly lit, oil platform or ship. And so if we're doing that, there is a real concern that that's such an important part of the carbon cycle that daily sink. It's the biggest movement of biomass on the planet every day. If we're messing that up with light at night in the marine environment, we could be having a much greater effect than we imagine on, you know, the whole issue around carbon and the atmosphere, which is of course, one of our biggest problems. Global warming.

Peter Bowes: 33:35

And as you say, this is multi-layered, extremely complex. And I guess to some extent, from what you've been saying, for at least for human beings, we might be better to go back to the old ways of doing things and having it generally dark at night. But obviously bright light, especially in a city center, equates to safety.

Philippa Gander: 33:55

Not so. So you see, this is. That is a misconception and a very common one. Very bright light is not safer at night. Very bright light makes your pupils close down so you can't see things that are in dimmer areas. And there's a glorious example I've seen of this where you're looking at a an image, or you're looking at a video of looking down the side of a house which has got, you know, a path going down and the back door in the middle, and you've got a very, very bright light over the back door. A security light makes you safe. and at the far end of the of the path, you can see that there's a gate. If you cover the white light with your hand, you can see that there's a person at the gate because your pupils open up again when they're not, you know, they're not blasted by that white light. And you can see there's somebody at the gate. But when you've got a security light on, you can't. And this is a big misunderstanding. There are I believe it's in Scandinavia. There are some countries or some towns that are experimenting with the idea of less bright light and actually improving safety at night, because the challenge is we believe that we need that really bright light, but actually that's not the case.

Peter Bowes: 35:09

That's really interesting because obviously you go to, let's say park in a in a busy street, and a lot of us would choose the parking position under the bright light because we just assume it's going to be safer. Perhaps when we return to the vehicle, we're fumbling for our keys and we're going to be seen.

Philippa Gander: 35:24

Yeah, well, you'll be seeing what's in the bright light, but you won't be seeing what's happening in the shadows around you. That's sort of the message. So there are a lot of things about our, you know, our fixation about light at night, which are actually can be challenged. And the other thing is, you know, there is a whole dark skies movement. There's an organization called Dark Skies International, which is a not for profit. And they are helping communities who want to actually return to a darker sky. And there are lots of technological things that we can do and not in any way, you know, affect safety. In fact, possibly improve safety. But and there are different types of writing which can provide what we need without doing so much environmental damage. We've got all that fairly at our fingertips, but we're not doing it necessarily. It's an interesting one for me because of course, being in New Zealand, we have a lot of dark skies and we take it for granted that you can walk out and see the Milky Way. And I just spent a week with a friend in the Piedmont in Italy, and I couldn't see any stars for a week, And then I spent some time with my son in Paris and couldn't see any stars, of course. But, you know, there's more and more awareness globally that we are. That's a very different aspect of light at night, but something which is sort of very central in a lot of human history and in our, you know, our whole relationship to the planet is our ability to see the stars. And so there's a whole movement now, to have dark skies. I've been involved with a few areas in New Zealand where communities are moving to having dark skies for their own health and wellbeing, but also because it's a major tourist attraction. A lot of people are now wanting to come and see what it looks like to see the stars, and the first time I really ever did it, I was invited to a there's an island off the north. what is it? The north east coast of New Zealand called Great Barrier Island, and they are a dark sky sanctuary. So they've met the international standards. And, you can walk on the beach in starlight. You can see enough in starlight to be able to walk on the beach. And you can see the Magellanic Clouds, which are outside our galaxy with the naked eye. You know, it's quite astonishing what you can see when when there isn't a lot of light bouncing around in the atmosphere. And so it's, I think the whole there's a whole, it's a more esoteric side to it, but it's also got a scientific basis. The whole, you know, love of the night sky is something which I think a lot of us have lost and never seen. And that, to me, is very sad. now that I've become aware of it myself. But that was the biggest revelation for me. I hadn't really looked at that literature very much, but when I was writing the last chapter, I was thinking, you know, well, what is the big picture here? We know that we're doing this. And I started looking into it in more detail. And so that's become a bit of a passion for me. you know, to realize we could do this differently and it would make a huge difference for us, but it would also make a huge difference for the whole all of the ecosystems that we rely on.

Peter Bowes: 38:29

And I think you could probably sum up a lot of what you've been saying, what you say in the book, as, as just greater awareness of these issues and an understanding of the issues as they apply to us. And just just in closing, I'm just curious in terms of the beneficial impact of understanding, certainly about our own circadian rhythm, circadian clocks. A morning routine for an early morning person, someone who likes to get up at the crack of dawn. How can we spend our time in those first few hours of the day to positively impact ourselves, because we are doing things that are in sync?- to use your phrase from the book - with the way that we are made, the way that we are functioning in terms of you talk about the biological clock in every cell of almost every cell of our body. How can we use that knowledge to our advantage?

Philippa Gander: 39:19

Well, I think the other thing that you need to realize is that you have different things, different types of activities are peaking at different times in the day. So your best brain function, your cognitive function is usually best late morning around lunchtime. a bit earlier for those of us who are morning time, a bit later for those who are evening type, but, you know, do all your brain work in the morning and up and up to lunchtime and then your physical, speed and dexterity and everything else are better. Uh, sort of early evening as your, as your circadian wake drivers peaking. And so, you know, if you really want to show off your athletic prowess, maybe that's the time you should be trying to do that. But I think it's a matter I don't think there's any specific answers except the things for me that, you know, set me up for the day. I don't think that's a scientific answer, but I know that if I get up in the morning, you know, and if I want actually, I do sometimes exercise in the morning, but I generally if I've got some nagging kind of brain work to do, I get on to that as fast as I can, have breakfast first and then get on to that as fast as I can. But that's, you know, I think there's personal preferences in that as well. And I don't think yet there's a lot of science to give you good advice, but I think one of the most important things is actually sort of observing yourself a little bit more, not just doing and rushing, you know, taking, paying attention to actually what works and what doesn't.

Peter Bowes: 40:42

Philippa, this is a fascinating subject. The book is Life in Sync The Science of Internal Clocks and how we're disrupting them. Really interesting conversation. I appreciate your time.

Philippa Gander: 40:52

Thank you.

Peter Bowes: 40:53

Good luck with the book. And thank you very much.

Philippa Gander: 40:55

Thanks.

Peter Bowes: 40:56

The Live Long podcast is a healthspan media production. I'm Peter Bowes. You can contact me through our website, livelong Podcast.com, where you'll also find show notes for this episode.

DISCLAIMER: 41:08

This podcast is for informational, educational and entertainment purposes only. We do not offer medical advice. If you have health concerns of any kind or you are considering adopting a new diet or exercise regime, you should first consult your doctor.