ļ»æEpisode 198 - Optimising your circadian rhythm for better health
Mel:
[0:00] Welcome to the Great Birth Rebellion podcast. I'm your host, Dr. Melanie Jackson. I'm a clinical and research midwife with my PhD. And each episode, I cast a critical eye over current maternity care practice by grappling with research and historical knowledge to help you get the best out of your pregnancy, birth, and postpartum journey.
Mel:
[0:24] Welcome everybody to today's episode of the Great Birth Rebellion podcast. I'm your host, Dr. Melanie Jackson, and today I want to talk about sleep and circadian rhythms and how to have a good, healthy circadian rhythm. And I've invited my friend, Max Gullhain, who is a medical doctor. And Max has a special interest in the maintenance of health through the maintenance of a healthy circadian rhythm and healthy sleep patterns. So I've invited Max today to not only talk about how we can sustain our health
Mel:
[0:57] before and after pregnancy, but also how to do that during pregnancy. And Max, I'm keen to ask questions to you about how women and parents who've got children and whose sleep is scattered, how we can still have optimal circadian health. Hello, Rebels. If you'll just give me 40 seconds of your time, I would like to personally thank the sponsor of this podcast because that means that you get to listen for free.
Mel:
[1:24] Poppy Child from Pop That Mama is a doula and hypnobirth practitioner, and she's the sponsor for today's podcast. Poppy has an online course, hypnobirthing course. It's called the Birth Box, and it's already helped thousands of women five-star reviews across the board. And you know me, I am very picky about what I will endorse, but I get behind the work that Poppy is doing in the birth box. It's practical strategies to help you get ready for labor and birth, but also the challenges of parenting. And with my code, if you type Melanie in at the cart, you'll get 25% off. So if you're preparing for birth, go check it out. You will be so glad you did. The link is in the show notes. Type Melanie at the cart and get 25% off. Thank you Poppy for sponsoring this
Mel:
[2:15] podcast so that everybody else gets to listen completely free. Let's get started on today's episode. So thanks for being here at the Great Birth Rebellion podcast.
Max:
[2:26] Thank you, Mel. It's my absolute pleasure to speak to you today.
Mel:
[2:29] I'm going to give you a chance to introduce yourself now because I know that
Mel:
[2:32] I just gave a little tiny piece of the story.
Max:
[2:35] Certainly. I am a currently practicing general practice registrar here on the northern rivers of New South Wales and I'm conventionally trained. I did my undergraduate science degree with research honours at the University of Queensland and then a MD medical degree down at the University of Melbourne with a Master of Public Health. And I worked as a junior doctor and into family medicine training, but had my own parallel patient journey where I had experience of, I guess you could say, an inadequate experience.
Max:
[3:12] Attempt or adequate way that the mainstream medicine or treatment protocols were able to help me. And my particular condition was acne. And I had a progressive experience with acne treatments and found that it wasn't treating the root cause of my problem.
Max:
[3:34] And delving down into the lifestyle determinants of this issue of acne led me to ask really deep questions about how medicine is addressing disease, how is it preventing disease, and what evidence is there for alternative, but no lesser evidence-backed, but simply alternative interpretations of existing scientific literature and biomedical literature that help us as practitioners, as clinicians, to prevent illness and address root causes of illness and therefore potentially avoid some of the side effects of certain medications. So in this journey, I learned that light and And the light environment is absolutely paramount importance to health. Essentially, what is happening here is that our sun, it's a star and it emits starlight. This starlight traverses the distance of space and it hits planet Earth. That sunlight gets filtered.
Max:
[4:46] By our ozone layer. And what we're left with standing on Earth is essentially energy and it's free energy. But the energy goes away on a 24-hour cycle as the Earth spins. But what it means is that all the organisms on planet Earth, from the smallest bacteria all the way up to complex multicellular life, which is plants, fungi,
Max:
[5:12] And humans, and animals, mammals, amphibians, reptiles, We all, in our various ways, have adapted to the presence and the absence of sunlight. So what that allowed us to do is to really make the most of our environment and essentially survive. And the convenient thing that that enables us to do is to put a whole bunch of important processes during different times of this 24-hour cycle. And really, the most basic one is wakefulness and sleep. So what we do during when we're waking is finding food, digesting and doing bowel motions. And then at nighttime, when the light disappears, we are able to enter this restorative phase and essentially repair the body for the next day. So those are the givens. And natural sunlight has a very unique signature. And it's an irreplaceable signature. And what we're doing today, what most people are doing by living inside, using devices at night, is a poor, fake substitute for natural sunlight. So what the human body evolved is a system to synchronize our internal state. And our physiology, our hormone production, our immune function, reproduction, metabolism,
Max:
[6:39] Stem cells with the external environment and the shift in this 24-hour light availability. And that is the circadian system. And the circadian system is another way to think about it is the body clock. And what it's exactly doing is my passion to explain to people and to understand. So what actually happens is that your eye has more than one function, but a small number of cells in the retina are not image forming, but they respond to the presence and absence of blue light. They're essentially blue light detectors. And those blue light detectors, they have a VIP access, a highway straight to a very important part of the brain where they trigger
Max:
[7:28] This so-called master clock. And the master clock has the job of telling the body, of synchronizing the body, all its internal functions and hormones with that outside environment. When we see, when we get up in the morning, we see bright daylight, morning light, those blue light detectors get triggered and they trigger a wiring diagram that goes all the way to the brain and then to this special gland called the pineal gland. And what they do is it turns off the sleepy hormone, which is melatonin. And melatonin has many, many functions. We're going to talk about them. But one of them is to promote repair. And you can only make melatonin when there's no blue light in the environment. And that will become really relevant when we think about what people are doing with phones and devices and blue light that's being emitted from these devices at night. But for the sake of understanding, a healthy circadian rhythm starts with bright natural daylight in the morning, which obviously contains blue, and that triggers the morning response. And the opposite to melatonin is a hormone called cortisol. Cortisol is normally associated with people with stress.
Max:
[8:46] And absolutely, that's what happens when we get up. But it's an appropriate and healthy amount of stress response, which is that cortisol spike as your melatonin goes down. These hormonal signals that are getting secreted and made are all in response to the light that we show our eyes and our skin. And in addition to the central pacemaker or the central clock in the hypothalamus, the body has clocks all through the body. And all through the organs. So, clocks in all the metabolic organs like the liver, like the pancreas, like the fat adipose tissue, like the muscles. And it has clocks in the heart, in the lungs, in the skin. And essentially, the body is looking to synchronize everything together. It needs the light that's hitting the brain and the circadian signals to all be congruent between all those different organs.
Max:
[9:44] So when they're not synchronized for a number of reasons, like say eating at 10 p.m. At night, then you get desynchrony, you get a difference between these central and your peripheral clocks, and that causes haywire chaos. So what I think is a really valuable way of thinking or useful way of thinking about the circadian rhythm that many people can relate to is the yin and yang sin so yin and yang has two equal and opposite opposing features.
Max:
[10:18] It's the bright, white, yin and yang, white and black. And that duality implies an equal necessity for bright daylight and dark night. You need both. If you have inadequate daytime sunlight because you're inside all night or day, you're going to disrupt. You're going to need an inadequate circadian stimulus and what we call a circadian amplitude is going to be impaired.
Max:
[10:50] And similarly, you need that dark, dark, dark night. And think back to even 200 years ago, because we only invented electricity in the late 1800s, everyone's nights were essentially really, really dark. And there's a huge discrepancy in the lux, which is the brightness, between natural daylight which can be up to 100,000 lux, and nocturnal true darkness, which is just moonlight and starlight. That can be as dark as 0.001 lux. So we're talking massive orders of magnitude and different of brightness intensity. And if you have that contrast, then the body has this amazing ability to repair overnight, to make all the right hormones at the right time, and everything just hums along fantastically well. What we are doing today is that we are, instead of having that nice black night and that really bright day, everyone's yin and yang is essentially like shades of gray.
Max:
[11:56] Because we're not getting enough bright sunlight and we're getting too much light at night. So what happens when that occurs is that we get circadian rhythm disruption. And look, there's other ways of doing it. You can also jet lag and shift work. These are the archetypal examples of circadian rhythm disruption. And we have reams of data to show how damaging that is to health when you get disruption of the circadian system. So the really basic approach that I try and advise people to prevent chronic disease, to optimize health, optimize hormonal function, and we're going to talk about as this relates to pregnancy and reproduction, is that we need to reestablish and be extremely diligent and intentional about our life choices. Because this isn't simply a convenient thing to do. This is a fundamental biological need.
Max:
[12:56] We can't step outside of those physiological blueprint that we've made. And if we do, we're going to get sick.
Mel:
[13:04] I'm going to give laypersons because, I mean, I know a little bit. I know that we need to protect our circadian rhythm and that it's somehow attached to hormonal regulation and our general health. So what you're saying is we need, the human body needs as basic things.
Mel:
[13:23] Building blocks of health in the same ways we need to breathe in and breathe out. We need a clear day of light and a clear segmented time of complete darkness and night in order for our body systems and our body clocks to work efficiently.
Mel:
[13:44] And our eyes, the function of our eyes is to detect how bright the light is and how dark the light is. And the bright morning light and the daylight has blue light which is what helps to set and regulate our internal body clock and we get that from the sun but it can also be got from internal lighting external lighting screens also emit blue light if we have too much blue light that can throw out our circadian rhythm particularly if we're exposed to blue light at a time we're supposed to be where it's supposed to be dark because the dark time is a time of regeneration and rest and recovery so that we can function optimally during the light time amazing amazing fantastic okay because that's what i got from your conversation from that explanation so that's excellent because what that is saying is that all of us pregnant or not our bodies are fundamentally We're mentally set to receive light and dark
Mel:
[14:52] at certain times and we need a certain amount of it. And as you alluded to, there's elements of our modern lifestyle that's messing with our circadian rhythms.
Mel:
[15:03] So can you talk next about, because something that women's bodies are incredibly governed by are our cyclical hormones that take us through our reproductive cycles, our menstrual cycles, our pregnancies. We rely on hormones for breastfeeding and pretty much everything. I'm sure men do too, but you know, the topic of today is women's bodies. You said that melatonin is really important in the circadian rhythm which is high at night so the melatonin gets triggered by the blue light dropping I assume yep Max is nodding so less blue light triggers melatonin and then we're obviously given cortisol in the morning when the sun comes up because that's kind of like our body going right time for action get moving this is our active time this is where we do things in the light and then the cortisol drops and melatonin increases and we get all drowsy and dopey for the night time. What other hormones are reliant upon a healthy circadian rhythm and what happens to us as women when we don't have our circadian rhythm in balance?
Max:
[16:18] That's a very good question. So, and what the circadian rhythm refers specifically to is a 24-hour rhythm. But it turns out that the body has rhythms or influence on longer time periods or longer scales. The menstrual and the female reproductive function was historically, and I guess still is, although it's been disrupted again by artificial light, is a 28-day rhythm, which is a lunar rhythm. And there was a recent study published, I believe it was in Science, that was examining how relating to a 28-day cycle, and again, female reproductive function linking to a normal lunar night or night with just moonlight. And obviously, the phases of the moon across 28 days, that varies in the brightness of that. So, you would imagine that in our ancestral past,
Max:
[17:25] That differing amount of moonlight that we would have been exposed to across every month was being received by the female body to ensure regular ovulation, regular menstrual cycle. Interestingly, if we look at non-vertebral species, particularly corals, their spawning cycles are robustly entrained by lunar rhythms rather than circadian rhythms.
Max:
[17:53] What it says is that organisms are really paying attention to natural light, sun, and the moon. What's gone wrong is that when we fill the night with light pollution,
Max:
[18:07] Cds etc then uh this is potentially interfering with those the messages and you know it's an open question and i think probably highly individual to what extent one one person's or one one woman's menstrual cycle might be disrupted or contributed to by you know light pollution but definitely on average, the light that people are receiving through their phone is nothing like both in brightness but also in spectrum, the nocturnal light signals that we were supposed to receive, which were extremely subtle.
Max:
[18:45] Specifically with respect to the other hormonal cycles, the pituitary gland, which sits in the brain, a midbrain, it can be thought of as like the pharmacy for the body. And it makes and coordinates all these what we call endocrine axes. So people might have heard of the hypothalamic pituitary adrenal axis, the hypothalamic pituitary gonadal or ovarian axis. All these axes refer to how the body is regulating hormonal functions. And they all are taking input from the hypothalamus and from these light-sensitive areas. When people ask, I see women too who say, oh, can we check my hormones? I think my hormones are a bit disrupted. The essence of normal hormonal health is going to be appropriate circadian signals because that is the most upstream determinant of healthy hormonal function. And if we look at hormonal sensitive cancers,
Max:
[19:52] Breast cancer, prostate cancer, we see a really strong and consistent signal with circadian rhythm disruption. And the US National Topps Ecology, they've designated shift work as a carcinogen. And they specifically state that artificial light at night and shift work is a risk factor for developing breast cancer. Melatonin, which as you mentioned, was the hormone that gets secreted, when the blue light drops and the body is no longer potentiating that pathway, that melatonin has a suppressive effect on aromatase, which was related to the female estrogen signaling. So there's lots of ways to disrupt hormones in this day and age, and sure, things like environmental endocrine-destructing compounds are not helping. But fundamentally, normal hormonal health, normal ovarian function and placental function, because the placenta is also regulated by circadian function, it's coming back to getting that bright morning daylight and getting melatonin or darkness so the melatonin, cortisol and circadian function can operate properly.
Mel:
[21:06] And I've got a whole episode on melatonin and how it relates to oxytocin in labor. And what we know about melatonin too, for those who have not heard this before, when they had a look at the impact of melatonin on oxytocin, which is what starts and continues labor along.
Mel:
[21:25] Melatonin potentiates the activity of oxytocin by 100. So this makes total sense as to why women would go more likely to go into labor at nighttime because of the high melatonin state, but also why women have the experience of their labor slowing down when they arrive in hospitals, which are full of fluorescent lights and they're full of blue light at every time of the day. So when women go in and they're laboring and they're trying to make sure that their oxytocin system is working well, all of a sudden the melatonin levels are dropping because of their nighttime exposure to blue light. So I think this story runs so deep. And the overarching message is, is that the circadian rhythm and this light
Mel:
[22:11] and dark necessity, it governs our body clocks and body hormones. And some people will be sitting there going, oh, as if light could be that powerful, as if it's that significant. But this is just basic physiology. This is just how our bodies work. So we're not, this is not new information. This is just we're able at this point in history to research and understand how our sort of modern lifestyles are impacting our more ancient bodies.
Max:
[22:41] Absolutely. But as that relates to pregnancy and birth, it makes sense that
Max:
[22:46] historically mammals would want to have birthed in darkness. And it makes sense that onset of birth is times with the greatest secretion of melatonin from the pineal gland. With respect to the I guess, cessation of birth, what you've said about melatonin and oxytocin, that synergy is absolutely correct and a fascinating piece of physiology. And what I think is, as you've said here, is that potentially women's birth is started in a nice dark area with a candle or a salt lamp and you move into the hospital environment. And hospital lighting and the hospital light environment is an area that is so ripe for revision because of the effect or lack of appropriateness of those light signals in terms of healing. But what it's doing is it's exactly what you're saying, is that
Max:
[23:48] When that person walks into that brightly lit corridor, then you have a massive amount of this blue light. It stimulates this melanopsin, which is this blue light detector in the retina and probably on the skin as well. And what we know is that there's people have extreme variation in sensitivity to this blue light. So some people get melatonin suppression or melatonin turned off at 400 lux, some of it is even lower, 5 lux.
Max:
[24:22] So perhaps the women who are seeing the most impact on their birth progression could be exquisitely sensitive to light at night. And that's enough to turn off that melatonin and then the whole system stops. So it's unfortunate, but the birth suite, I would just say, is not the only part of the hospital that needs to be revised with respect to the light environment. The ICU, the NICU, I mean, a lot of it, and especially geriatric wards and the dementia areas, they all need to be revised because we're blasting isolated LED light, which contains a huge spike in this 480 nanometer cyan light. It's got no or very minimal red and longer wavelength visible light, and it's got nothing into the near infrared, which is what is a characteristic of natural sunlight. So as I talk about, and we talk about refined food, processed food is bad for your health. What we're living under is processed light.
Mel:
[25:25] It is junk light.
Max:
[25:27] Junk light, junk light. It's alien. It's, it's, it's like a cheap imitation of sunlight. And, and that is, has really, really significant consequences.
Mel:
[25:37] I just looked around my office and, and realized that I have my blue light blocking glasses in here so that I don't feel so bad when I'm on my computer, when the sun's gone down. And actually I recommend for women, part of their birth kit should be some blue light blocking glasses and an eye mask and that they're really conscious about utilizing them at times to try
Mel:
[26:03] and block some level of that blue light during labor to increase their oxytocin function. Okay, Max, so how much? Because I know there'll be women listening who think, my gosh, my whole nighttime is actually disrupted by children and all kinds of things.
Mel:
[26:21] How can we optimize our circadian rhythms when our sleep is interrupted. Does the amount of sleep matter or is it just important that it's dark at night? And I also want to know if naps count for this restorative time, if, for example, we're living in a stage of our lives where our sleep is disrupted.
Max:
[26:44] Great question. So there's multiple different factors that affect the onset of sleep and And sleepiness itself is actually mostly contributed to by a compound called adenosine, which accumulates and drives what we call sleep pressure. So you've been working all throughout the day. You've been very busy doing things. You're going to build up sleep pressure through this adenosine and then sleepiness. Provided there's minimal light at night then melatonin gets secreted and that's like a gate a check gateway to permit deep sleep what we know is that if there's people suffer from sleep maintenance insomnia which is they're going to sleep okay but they're waking up multiple times that is often resulting from an inadequate amount of daytime sunlight and we won't necessarily go into the photobiology of it but being awake and guessing that bright daylight essentially helps the body make and produce the precursor compounds to melatonin so it's like charging up a battery that then gets discharged during the night time so what i'm saying is your best quality sleep is actually made during the day and it's made with early morning light and it's early morning light exposure, and then it's solidified by darkness and night.
Mel:
[28:07] So we're like solar panels. It's that we have to be out in the sun enough in order to function properly when the sun's down.
Max:
[28:16] And Mel, it goes so much deeper that, I mean, I don't want to go in too many technicalities, but essentially there was an optics engineer who studied his whole career looking at the optical properties of engineering aircraft. And he essentially turned his opinion or his investigation to the human body. And what he essentially learned was that there are these massive number of anatomical nuances in the design of our body that are optimized to concentrate specific part of the solar spectrum in the near-infrared, which is near-infrared is beyond red. So we can't even see it. And that's something we'll talk about next episode, which is when we talk about natural sunlight, is visible light is a narrow spectrum of
Max:
[29:05] Beyond visible, we're getting a whole bunch of light nutrients that we can't even see. But it turns out that the body, particularly the cerebrospinal fluid in the spinal column, the gyri and the sulci, the grooves of the brain, and even the uterus have been optimized to essentially harvest and collect these near-infrared photons, which are able to induce an antioxidant effect in the body. And when you learn about what melatonin is doing in pregnancy, it's acting as an antioxidant. And before it was a signal of darkness in the human circadian circulatory system through the pineal gland, it was an antioxidant in primitive bacteria. So it's still having that effect because it has multiple roles. So what that near-infrared light is doing is that's actually bathing the fetus in a sphere of near-infrared when we're outside. We'll talk about that more. The body has these anatomical adaptions to be essentially solar collectors. What we have to do is just to be smart about the light that we show ourselves, and we have to obviously be appropriate in the amount of light, especially the amount of short wavelength light, which is in the ultraviolet, depending on our skin type, our ancestry, and what part of the world, what latitude we live in.
Mel:
[30:34] So should parents then, for who are thinking, oh my gosh, my nighttimes are so disrupted, is the first step, instead of thinking, gosh, how can I fix my nighttime waking? First step is get enough light exposure during the day. And then try and optimize the nighttime environment with things like we have little lamps that we turn on at night that don't emit any blue light. So they glow orange essentially. And then you can put your blue light blocking glasses on for extra measure. But if you're waking at night, one way of making sure your melatonin is not too disrupted could be, especially if you're waking to children or a baby, Okay. Is to have a lamp or some lighting that doesn't emit blue light as a starting point. If parents are calculating their hours of sleep, how many hours of sleep are optimum? From a scientific perspective, we all know that we might not be getting enough of those in some stages of our lives, but what is an optimum amount of sleep?
Max:
[31:39] In terms of what people can do immediately cultivating a dark night is is probably the first thing before we change our routine to get morning light both of them are equally important but if we're talking about and the average person who's just trying to start making changes with respect to their light habits then absolutely what we need to do first is start creating some intentional nocturnal darkness. So what does that look like? Most people have LED downlights in their kitchen, in their rooms, all around them. So the first step is when the sun goes down, you don't turn on LED downlights because it turns out that it's not only the presence of blue light, but it's also the position of the light hitting the retina that can have a stimulatory effect. Because the only time we had overhead light in our ancestral history was the sun at noon. And the most LED lighting, they are in what we call it's an extremely high color temperature, meaning that it's corresponding to noonday. So we don't need to go too much more into technicals to understand that that's a disrupting signal. So the first thing I would advise people is to turn off overhead lighting.
Max:
[32:55] Next, use dim lighting, the least amount that you need to get what you need done. So in our kitchen, we have one lamp that goes on in the evening and that's sufficient light to make, prepare or finish anything else that we're doing during the day. And that is actually an incandescent light bulb. And incandescent were the standard of light bulbs before the,
Max:
[33:21] The regulations change with respect to energy-saving lighting. And why isn't an incandescent better? Well, essentially, the incandescent bulb uses electricity to heat up a filament. That filament makes a really nice warmer color temperature light and it also has less flickering than LED lighting. And flicker is another whole problem that can drive headache, migraine, and the rest. So if we use a really warm lighting source like an incandescent bulb, which you can only get on eBay now, or a really warm LED that lacks blue, so either the yellow, the orange, or the red, then we're kind of ticking a couple boxes.
Max:
[34:05] If we put it at the bench height, there's no light overhead. We've eliminated the blue or minimized the blue that's going to trigger our blue light receptors and turn off our melatonin. And finally, keeping the lux or the intensity nice and low. So those are the three things to think about is how bright is it, what color is it, and what position is it? If we can be intentional about those three things, we're setting ourselves up
Max:
[34:32] for a really good night of sleep. So we're going to put that that light nice and low it's going to be a warm color temperature and then as we get closer and closer to sleep we need to uh even further be be more strict and and you held up your blue blackers and they were quite red and what the redder lenses do is they provide more and more filtration of that activating short wavelength light so they even melior glasses even block green and green light can also have this suppressive effect. So we've got our warm light on and then as we're going into sleep and bedtime and reading...
Max:
[35:09] I use a red LED, a very dim red LED in our bedroom. And everyone reads, we read books with this small, one little red LED lamp. And then when the reading's finished, an hour, 45 minutes after sunset, then it goes off. And what happens? The body dumps melatonin into the system because there's been no blue light, which is appropriate. And the outcome is that the onset of sleep is amazing. And the sleep is maintained because we've got a really nice healthy level of melatonin coursing through our body, helping us maintain sleep, repairing all the oxidative stress from the day. So this isn't just about the pregnant lady, but it's also about the child, the toddler, dad. Everyone is going to be sleeping better and maintaining that better sleep because of these just pretty simple light habit changes.
Mel:
[36:07] I mean, we know that breast milk changes at nighttime as well in response to increased melatonin, which, and when we're advising women, if they're pumping breast milk for their babies, we advise them to, if they're pumping at night, feed the baby that milk at night. And if they're pumping in the day, to feed the baby that milk in the daytime, because nighttime milk is also designed to make the babies more sleepy and more drowsy and sleep for longer periods. So it makes sense that if we're hormonally set, our circadian rhythm is hormonally set for sleep, that perhaps our breast milk will also be optimized for sleep as well. And actually, Dr. Pam Douglas, she was on the podcast speaking about infant sleep. And she said the best way to optimize a baby's sleep at nighttime is increase their stimulation and outside time during the day. Hey, she didn't make the connection in this circadian way, but it sounds as though the two are quite connected.
Max:
[37:10] Absolutely. And to make a point about that, Light, as I mentioned, is the most important time giver or zeitgeber for the circadian system, but meal timing is as well. So what pregnant women ideally would do is get some nice amount of morning light and then eat breakfast and eat, say, a protein-rich breakfast, and that obviously has other benefits. What we want to avoid is repeated nocturnal, really late eating because that can contribute to this desynchronization of the gut clocks and the central clocks, and that is linked in the literature to gestational diabetes. And for non-pregnant women, it's linked to diabetes, cardiovascular diseases, and all this kind of thing. So nocturnal eating is something that we want to avoid because of the importance of meal timing for circadian function.
Max:
[38:04] But as you really interestingly made the point is that the infant, before it gets born, the baby's getting these melatonin cortisol cues from the mother. So the melatonin cortisol that's been made in response to healthy light environment is being crossing the placenta and the placenta actually makes melatonin as well to entrain the fetal circadian rhythm. But post-birth, the baby is reliant on melatonin cortisol being secreted into the breast milk to entrain the infant, the baby's circadian rhythm. So as you correctly say, if you've expressed milk, it's ideal to be administering that milk at the time in which it was produced because the body is so infinitely smart that it's helping the baby adapt to the ambient environment with these really key time secretion of these circadian active hormones. So it's chrononutrition, what we call the field of chrononutrition, but applied to babies. And yeah, it's another one of these massive amount of nutrients. So not only are babies getting these fundamental important food nutrients, fat-soluble vitamins, immunoglobulin, whatever else, but they're also getting white nutrients through the hormones being secreted into breast milk. So it's just amazingly elegant.
Mel:
[39:31] I have to agree with you amazingly elegant is how I would describe the body's design and actually as you were talking about reading I'm here I am doing all these product plugs but this we have each of our family members has one of these and this is our nighttime reading lights and again they're blue light block there there's no blue light they glow orange but these are the ones we also travel with uh if we're traveling around we take these as our nighttime lamps for you know in houses and hotel rooms depending on what's happening but these are really handy for reading at night if you kind of think I still want to do stuff or you can you can pin these around the house too for anybody who doesn't want to invest in in in the adequate light globes you can get these mobile I want to tap into what you said about just gestational diabetes and diabetes as a possible consequence of circadian disruption and eating too late at night because there is a connection between increased blood sugar levels due to nighttime activity for women who have gestational diabetes.
Mel:
[40:41] I mean, as I was reading the papers on this, a lot of the studies about circadian rhythms and healthy nighttime habits and eating habits around sleep time, a lot of the research has been done on people with diabetes and what they've seemed, and you'll be able to, I'm sure, elaborate on this, but what I gathered was that people who have a healthy circadian rhythm.
Mel:
[41:05] Exposure to light in day, and then nighttime darkness, they're.
Mel:
[41:08] They are able to control and sometimes even cure their diabetes by adjusting their sleep and night, their light habits. I wonder if you could talk to us about that because certainly this would have ramifications for women with gestational diabetes as an additional element that they can add to their management plan because there are some women who just cannot control their gestational diabetes with diet, a bit reluctant to try any medication. So I guess, can we talk about this as an additional possible strategy?
Max:
[41:45] Oh, absolutely. And it's actually one of my passions, which is metabolic diseases, because that's what I see in general practice is this torrent wave of disease and suffering, which is downstream of insulin resistance, metabolic dysfunction and diabetes. So it turns out that metabolism is one of the key functions of the body that's regulated on a 24-hour cycle. And as I mentioned earlier, all the organs that deal with energy, they run on the circadian clock, meaning there's a time and a place for them to be used and time and a place for them to be relaxed and not active. So maybe this is to give a little bit of a crude analogy, is that imagine if you had a power plant that was burning coal, but overnight it went down to one smokestack or one reactor instead of four. If you keep trucking coal into that reactor when there's only one reactor online, it's going to take what it can, but it's going to send all the rest into storage yard because it can't burn it because it's the wrong time, it's closed. That is essentially what happens with chronic mistimed eating and chronic food consumption at nighttime, which is even made worse by
Max:
[43:05] The hyper-processed foods by high-carb foods and sugar and that macronutrient composition. And it's because the body becomes naturally and appropriately more insulin resistant as the night goes on because it's not optimized to processed food at 10 p.m. It's asking you to turn off daytime activity so it can start going to this recovery phase. So what we know from the chronobiological and nutrition literature is that we can improve glycemic profiles in type 2 diabetics by doing nothing else but bringing their same food to an earlier phase and aligning that food window with the wake window, with the circadian wake window, which is with breakfast, eating breakfast, and potentially an earlier dinner. And look, this is a technique that I use to help diabetic and insulin-resistant patients all the time. And that's what we call earlier time-restricted eating. And it's got evidence for helping address these fundamental overload of energy that occurs with insulin resistance and metabolic dysfunction. So if we can...
Max:
[44:21] Consume food, start the day with protein-rich breakfasts, focusing on animal sources of protein and healthy fat and minimizing especially refined carbohydrate intake. And then as later and later in the day goes, and obviously during maybe the first trimester, particularly women are quite hungry, but eating those more nutrient-dense foods and closer to the daylight hours and stopping may be one of the techniques that could help women to prevent gestational diabetes. And I was reading a study recently, it was a math study, it's called Maternal Circadian Rhythms During Pregnancy Dictate Metabolic Plasticity in Offspring. And this addresses the second-order effect, which is your circadian choices, your light choices and your circadian rhythms, they're not only affecting your health and influencing your risk of potentially pregnancy complication, but they're also imprinting your baby, imprinting the fetus with
Max:
[45:28] Epigenetic information, which can have negative health effects for the baby further on. And essentially what they noticed, if they disrupted these rat circadian rhythms, the pups were all smaller. They were essentially having the rat version of IUGR or more for gestational age. And the children, adult offspring, they were more prone to diets-induced obesity. They had displayed higher food intake they were you know more leptin resistant which is relates to their ability to regulate food and energy intake so to make it really real is that if someone's up at 11 p.m holding an ipad blasting their eyes with with this blue light then you know this is this is probably not going to be a great thing because it's infecting not only the maternal circadian rhythm and suppressing maternal melatonin, but also causing the similar disruption to the fetus, to the baby, with probable effects not only on her glycemic profile, but the baby's later on in life.
Mel:
[46:39] In terms of the pathophysiology of gestational diabetes, that's the kind of physiological insulin resistance that happens to our bodies.
Mel:
[46:49] And for some women that are prone, that'll tip into a gestational diabetic state. So what you're saying, if women eat during the daylight hours, when our body is expecting to function and be high activity, that's the time to eat. And then at nighttime, we go into a kind of naturally insulin resistant state. So any food that's going in is not being processed or at the very worst, it's being put away is adipose tissue.
Mel:
[47:18] Or actively increasing our blood sugar levels overnight and our body doesn't have the capacity to reduce our blood sugar level overnight because it's in this normal state of insulin resistance. And for those listening, actually when we diagnose gestational diabetes, a key factor for treatment is usually the woman's blood sugar level upon waking. For women who have uncontrolled diabetes, The one that they have the most trouble controlling is not usually the daytime blood sugar levels. It's the morning waking, the fasting blood sugar level is what becomes high. And so, Max, it sounds like what you're saying is we could potentially solve that problem with just changing the time of day that women are eating and enhancing the function of their circadian rhythm as an additional option. So if you're out there and you think, I'm doing all the normal diet stuff, I'm exercising, the missing piece could be managing your circadian rhythm and not eating at nighttime.
Max:
[48:21] It's something so simple, but yes, it could be a key thing that helps improve glycemic profiles. And there was actually a recent study released that looked at light exposures, natural versus artificial in type 2 diabetics. And the ones, they didn't even use natural daylight, but they were next to a window and those patients had a greater time and range for their blood glucose levels by simply just having natural light exposures and more natural circadian signals. So it's not rocket science, but it's simply making an attempt to not disrespect the engineering blueprint for your body with respect to mealtime.
Mel:
[49:00] I absolutely agree. Yeah. So basically what we need people to know is that your body has a natural circadian cycle that is triggered by your eyes exposure to blue light. Historically, before electricity, that would have been governed by the sun, which was easy because we didn't have to do anything. All we had to do was just keep living. But now we've got choices. We could turn on blue light at night time and many of us are choosing to do
Mel:
[49:32] that and that's having an impact on the physiology of our bodies. So I think that's the main point we're trying to make today is this night time light and night time eating is not innocuous, it actually can deplete your body's functions and shorten the amount of time that your body has to recover in that recovery state to maintain health. Is there any other missing piece that you feel like We just need to know if we're going to be able to really fully understand this, what we've spoken about today.
Max:
[50:03] The point that I really want to hammer home, because we'll talk about sunlight next time, is how important it is to cultivate this melatonin level. And I briefly mentioned breast cancer, and one of the reasons why breast cancer incidence or it goes up with light at night is because melatonin protects from, it's an antioxidant, but also protects against the development of malignant cells. So...
Max:
[50:31] Everything that we can do in this day and age to cultivate a high melatonin level, we're going to be ensuring that we're repairing adequately. And what that repair translates to is actually longevity. Because the inability for your body to repair chronically is going to lead to accelerated aging. And what we are seeing in astronauts that go into the space station is that they have, amongst a whole bunch of other stuff completely disordered circadian signals you there's this iconic image of one of these uh female astronauts who comes back from the space station only a year later and she was she's basically has a hair full of gray gray head full of gray hair uh in only what six eight months and so that's another whole topic but it turns out pigmentation of the follicle, hair follicle, occurs on a circadian cycle. And the loss of hair pigmentation and graying, the data's there, the faster physiology's there, it can be related to chronic circadian rhythm disruption because you're not getting adequate repair overnight. Another topic. But I guess- So interesting,
Mel:
[51:44] I'm curious though because I'm 42 and I do not dye my hair nor do I have very many grays. The only time I go grey is at times of particular stress or if I'm hustling hard at something, then I notice more greys. But then once the stress is gone, the greys don't continue.
Max:
[52:06] Yeah, so hair graying, I mean, there's multiple factors involved.
Mel:
[52:10] Yeah, sorry, I got on this train, Max, when you said that. I was like, wait a second.
Max:
[52:14] Nutritional factors, there's sympathetic innervation of these hair follicles. So the more you stimulate the sympathetic system with stress hormones, the more it happens. But the hair cycle, the follicle cycle, there's these phases of anagen, telogen that regulate the physiology, the health of the hair follicle, and the melanocytes that put pigment into the hair follicle, they all need healthy circadian signals. And if we have chronic circadian disruption, I mean, I look at someone and I always ask them what they do and you can make it very clear in my mind, I talk to a patient, if they have chronic circadian disruption because they're awake working from 4 a.m., from 2 a.m. Onwards, then often that correlates to something like that and really it's an external marker of accelerated aging.
Max:
[53:08] So I guess the point that I raised that is that pregnancy is a key time to be caring for your circadian rhythm because of its effect on birth outcome and because of its epigenetic printing on your baby but really this is these habits that if you can form them now they're going to hold you in optimal health long long long past part of your life and into healthy menopause into healthy aging and uh you know for the rest of your life so uh this is not a small thing and and feel free to not take my word for it do a pub med search you can see the reams of research on circadian rhythm disruption and kind of any and all medical conditions so i guess that That would be my final thought is think about the yin and yang
Max:
[53:56] With a clock over it. Think about the need for bright daylight and completely dark nights and think about that and think about what are you doing to cultivate nocturnal darkness and to therefore help protect
Max:
[54:11] your body's melatonin secretion and healthy sleep and healthy circadian rhythm.
Mel:
[54:16] So the summary of it is if we want to protect and enhance our circadian rhythm, it's bright daylight, dark night time, and then eat when it's light and then don't eat when it's not light at the very basics. And then if you really must put lights on at nighttime, the ones that don't emit blue light are the ones that are most helpful and then also you could utilize
Mel:
[54:42] the use of the blue light blocking glasses for people who absolutely can't avoid it. We are going to do, we're doing another episode which will follow this one And in this one, I specifically want to talk about the health elements of sunlight, not only on our eyes, but also the health elements of sunlight on our skin. So hang around, guys, for next week's episode. Max will be back where we're going to talk about the health impacts of sunlight. Thanks so much for your time, Max. We will see you in the next episode of the Great Birth Rebellion podcast. To get access to the resources for each podcast episode join the mailing list at melaniethemidwife.com and to support the work of this podcast wear the rebellion in the form of clothing and other merch at thegreatbirthrebellion.com follow me mel @melaniethemidwife on socials and the show @thegreatbirthrebellion all the details are in the show notes.
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