Ejo #155 – Let There Be Light

Last month I wrote about the health hazards of shift work, almost all of which are caused by the violence perpetrated against our circadian rhythms when we suffer from disrupted sleep.  Today I’m going to talk about why that matters so much.  Not just for shift workers, but for everyone. 

Over the last 50,000 years, we have driven the progress of our species forward at an alarming rate, transforming ourselves from primitive hunter-gatherers; first into farmers and then ultimately into what we are today (whatever you want to call that).  In most ways this progress has benefited us.  In many others, it has not.  The transition from hunter-gatherer to agronomist was thanks to the agricultural revolution approximately 10,000 years ago which is seen at once, as humankind’s greatest achievement, and our greatest failure.  It set us on the path that we find ourselves on today, by forcing us to settle in one place and allowing us to feed multitudes more of us, but it definitely wasn’t a benefit to our health.  Almost overnight, we went from chasing and eating a predominantly meat based diet, supplemented by tubers and the occasional fruit and berry, to a diet consisting almost entirely of grains.  It is commonly perceived that humans domesticated wheat, but the truer story is that wheat domesticated us.  And in doing so, it made us fatter and shorter, it made us more prone to disease and it significantly lowered our longevity. 

Things have improved, of course, and we now live long lives, full of creature comforts, mod-cons and all the good things that life has to offer.  But for all the progress our civilisation has made, our bodies lag behind, having evolved to survive the conditions that existed on earth 50,000 years ago.  We might be stuffing our faces with avocado toast and scrolling on our phones for hours, but our bodies still think we’re hunter-gatherers, roaming the plains of the Upper Paleolithic era.  All the progress we have made as a species has been truly remarkable, and the life that we’ve created for ourselves is an astonishing achievement, but for our animal bodies this progress has trapped us in a golden cage that is slowly killing us.  We no longer live in nature, and our bodies are paying the price.  To achieve optimal health, we all need to make more of an effort to return to our natural element, to get more fresh air, to move more and to get more sunshine.  This isn’t a new age, airy-fairy aspiration.  It’s a fact, rooted in hard science.  We need sunlight not just to thrive, but to survive. 

In his 1973 book “Health and Light“, which I recently finished reading, Dr. John Ott describes conducting research about how full spectrum light can improve our health, or make us sick if we are exposed to a distorted or incomplete spectrum.  Dr. Ott coined the term mal-illumination, which he compares to malnutrition, and which is caused by our widespread fear of the sun.  We aren’t doing ourselves any favours when we restrict our intake of full spectrum sunlight by shielding our eyes and skin behind sunglasses, tinted windows and sunscreen.  Doing so has created an epidemic of people who are deficient not only in Vitamin D, but in a very crucial, beneficial and life-promoting form of energy.  Sunlight. 

Of course we need to be sensible and not overdo it, because too much shortwave UV light is harmful, and can cause sunburn, premature aging and skin cancer.  But most UV light is long wavelength light.  It’s a nutrient, that nourishes us and gives us energy, and is just as important as the nutrients we consume from food.  In fact, it doesn’t matter how good your diet is, or how much you exercise, if you’re not getting optimal sunlight (infrared light, followed by red light, followed by UVA, and then UVB, in that order) you will never reach peak health.  You will always be operating sub-optimally.  And the scientific world has known that for a long time.  A 1967 study into illumination for health concluded that, “If human skin is not exposed to solar radiation for long periods of time, disturbances occur in the physiological equilibrium of the human system, resulting in functional disorders of the nervous system, vitamin-D deficiency, a weakening of the body’s defences and an aggravation of chronic diseases.” 

Speaking of Vitamin D, why are so many people supplementing with exogenous Vitamin D when all they need to do is go outside for a few minutes each day and commune with the almighty, life-giving sun?  Why are we all so happy to just pop a pill, when the answer to our health problems literally hangs in the sky outside our front doors.  Factors that affect your personal Vitamin D levels include where you live in the world, how old you are, what colour skin you have, how much you weigh, what foods you eat and what other conditions you might be suffering from.  How can all of that be effectively corrected with an over-the-counter course of vitamins created in a factory?  It can’t.  When we go outside and expose our skin to sunlight, the body knows what it needs to do.  It knows how much Vitamin D to produce and it creates the most bio-available form of it.  Two recent studies showed that increased blood levels of supplemental Vitamin D actually caused elderly people to fall over more often, and to suffer more frequent and more severe bone fractures.  And taking Vitamin D supplements has been shown in countless studies to actually increase the overall risk of cancer, and even death.  So stop popping the pills please, and just get out in the sunshine!!!! 

Sunlight isn’t just a requirement for Vitamin D synthesis.  Almost every living organism on earth dances to the beat of a circadian drum.  We all possess biological processes that naturally occur around a 24 hour cycle, usually in response to the position of the sun in the sky.  Humans are no exception to this.  Sunrise and early morning exposure to light kickstart the circadian rhythm into motion, communicating to every single cell in the body, and setting them all up to synchronise their tasks for the day.  This messaging is vitally important and we miss out on it if we don’t get that early morning light in our eyes.  But how many of us are willing to sacrifice that benefit so we can sleep in just one more hour.  Almost everyone has some level of chronically disrupted circadian rhythm, so it’s no wonder that so many of us suffer from constant fatigue, low mood, anxiety, infertility, erectile dysfunction and a plethora of metabolic issues.  And for some reason, we just normalise that.  We just accept that we feel that way.  And that’s not cool.  These symptoms are all treatable, and the prescription is sunlight. 

From daybreak to nightfall, the sun shines its magical and wondrous light on us, bestowing us with life and good health – that is, if we don’t hide ourselves away from it.  Sunshine contains light from the full spectrum; of course visible light, but also infrared, red and ultraviolet light. And all of these wavelengths are transformed by the body into energy which is required for a myriad of biochemical reactions.  The proportion of each of these wavelengths of light changes, depending on what time of day it is.  Infrared and red light is present in all sunlight, but is more concentrated at sunrise and sunset.  Infrared light is soothing, healing and anti-inflammatory.  Ultraviolet light appears sometime within two hours after sunrise, depending on your location.  UVA comes first, when the sun is around 10° above the horizon, followed by UVB some time later.  The Circadian app is a great source of information about what light is present at what time of day in your part of the world.

The Circadian app tells me exactly when UVA rises and sets in Dubai.

Receiving indirect UVA sunlight into our eyes comes with an abundance of perks, so for maximum benefits make sure to take off spectacles, sunglasses and contact lenses, but please don’t look directly at the sun, mmmkay. Morning UVA actually prepares our bodies to receive the stronger UVB light later in the day.  Clever, right?  It’s almost as if we were designed to be outside in the sun.  UVA is also the precursor to the release of thyroid hormones that are needed to regulate our metabolism, energy levels and weight, as well as hair, nail and skin growth.  And it also releases a beautiful rush of feel-good hormones like serotonin (which makes us feel happy), dopamine (which makes us motivated and curious), norepinephrine (which focusses concentration) and beta endorphins (which give us a runner’s high and makes us lust after sunlight even more).  These are the same hormones that get people hooked on drugs, alcohol, gambling and other problematic behaviour.  The only difference is that when you’re addicted to morning sunlight, you’re getting high on life.  Literally! 

Sunlight is the trigger for so many biological processes, and we receive that signal not just in our eyes, but also through our skin.  The skin is an amazing self-regulating organ which not only protects our insides from spilling out, but also allows us to experience touch and changes in temperature.  It quietly and efficiently battles the harsh external world, ensuring that our body remains in homeostasis on the inside, despite what might be happening on the outside.  It does this by facilitating constant two way communication between itself and the immune, endocrine and central nervous systems.  Our skin is a beautiful, complex and elegantly designed system, which has evolved over millennia to absorb UV light for beneficial metabolic and biochemical reactions. 

One surprising benefit of exposing our skin to UVB light is an increase in the sex hormones oestrogen and testosterone (both of which are present in men and women), resulting in a natural increase in libido.  And who couldn’t use a little pick-me-up in that department?!  In his very informative, and fascinating, podcast about the health benefits of light Dr. Andrew Huberman suggests a protocol designed to boost reproductive health and libido.  All you have to do is expose as much skin as you (decently) can to the midday sun for about 20-30 minutes a day, two to three times a week.  This protocol is based on studies conducted on humans that showed not only a significant blood serum increase in oestrogen and testosterone, but a psychological increase in perceived attractiveness of others as well as an increased desire to have sex.  I mean, c’mon, if that sounds as good to you as it does to me, let’s get on out there in the sunshine people.  Testosterone levels in men have been declining for years. This is a beautiful way to remedy that. Following this protocol takes about a month to start feeling more randy, so what are we waiting for?  Let’s go get it.

UVB doesn’t just make us horny.  It’s the magic ingredient for producing that essential, endogenous Vitamin D we were talking about earlier.  And when our eyes and skin are exposed to it, it also increases our pain tolerance, and boosts our mood and energy levels throughout the day, and I don’t know how you can put a price on that. 

I recently broke my ankle and was stuck at home for three weeks doing ATC office work.  It was the perfect time to start a morning sunlight protocol, as I wasn’t doing shift work, and I was able to stick to a consistent schedule.  My routine is extremely simple, but provides outsized benefits.  Every morning, I get up and go outside to watch the sun rise, staying outside for about twenty minutes.  Even three or four minutes is enough to get some benefit, but I like to stay out there for longer.  I gaze up at the brightest part of the sky, while avoiding looking directly at the sun (obvs).  After twenty minutes, I go inside to prepare and eat a high protein snack, before stepping back out and spending another twenty minutes exposing my naked eyes to the light, just as the UVA wavelengths begin to emerge. 

Catching the early morning rays from my balcony.

I’m not gonna lie, when I first started my routine, getting up so early in the morning was hard.  It was really hard.  Like, so, so hard.  But after just three days, I actually started looking forward to waking up before dawn.  I crave it now.  I love being up when most people are still in bed.  I love listening to the birds singing in the trees, feeling the cool sea breeze on my skin and witnessing the creation of each new day.  It’s a truly beautiful experience and a wonderful way to start the morning, setting me up to be healthier and happier all day long.  Getting UVA actually makes me feel hopeful, happy and full of love.  It washes over me like a warm blanket, giving me a wonderful feeling of wellbeing, and I finish each session with a huge smile on my face.  I feel so fucking good from making this tiny change to my routine.  The vast improvement in my mood, mental health and energy levels absolutely makes it worth getting up so early every day.  Going back to shift work has unfortunately made it slightly more difficult to be consistent in my routine, but I still make an effort to get early morning sunlight in my eyes, every single day, even after working a night shift.  Sunlight is the cure, and I’m out there every day, religiously taking my dose of medicine as if my quality of my life depended on it. Because it does. 

So we’ve talked about what we need to do during the day to improve our health, and now it’s time to discuss what happens at night.  We learned that UVB is great during the day, but it probably won’t surprise you to learn that it’s not so great after dark. 

We’ve all heard of melatonin, right?  It’s well known for helping us fall asleep, but it also has several other functions in the body, both regulative and protective.  These include stem cell production to make our bones stronger, the regulation of cardiovascular function and activation of the immune system.  Physiological melatonin has also been shown to have a very dynamic anti-oxidant effect, and even some anti-cancer properties to boot.  Contrary to popular opinion though, this doesn’t mean that we should all run out and start taking supplemental melatonin.  Far from it.  The anti-cancer properties occur with the natural rise and fall of the hormone.  Taking supplemental melatonin for long periods of time, can severely reduce adrenal output resulting in the suppression of cortisol and epinephrine, which may be known as stress hormones, but which are actually required by the body in order to function properly.  Supplemental melatonin tends to be an unnaturally fixed, and usually extremely high dose of the hormone, and taking it at the same time every night drastically differs from the way in which melatonin is naturally released by the body, gently rising and falling according to the time of day and the seasons. 

So, what is melatonin, and how does it work?  It’s a hormone secreted by the pineal gland, which is found in the centre of the brain.  The excretion of melatonin from the pineal gland is dependent on what time of day or night it is, and is actually governed by light.  Bright light turns off the production of melatonin, and darkness prompts it to be secreted.  The pea-sized pineal gland, however, is located very deep in the brain, so how on earth could it possibly know what time of day it is in order to regulate the production and release of melatonin?  I’m glad you asked.  There is a fancy-pants cell in our eyes called the intrinsically photosensitive ganglion, also known as the melanopsin cell, which is responsible for absorbing sunlight, and escorting the signal through a series of messaging posts in the brain until it reaches it’s destination, the pineal gland.  Morning sunlight in the eyes is the catalyst that signals to the pineal gland that it’s time to gently reduce the release of melatonin, while at the same time triggering production of it for later that night.  Yes, paradoxically we need sunlight to produce the hormone that will help us sleep. 

Melatonin also communicates information to our bodies about how much light is in our environment, and therefore what time of the day it is and also what time of the year it is, which is just remarkable.  The environment around us, i.e. light, changes the environment within us, all thanks to the super-hormone melatonin.  Which is why we should be vigilant about getting more sunlight, as well as making an effort to avoid artificial light at night. 

Of course, in this (marvellous) modern day and age, it’s difficult to avoid artificial light after dark.  It sure would be awesome if we could all have open fireplaces, and homes lit with romantic candlelight.  And I can guarantee you that we’d all sleep a hell of a lot better if we did.  But unfortunately, that’s probably not going to happen.  So we need to focus on what we can do.  If you have dimmers, turn the lights all the way down at night.  If you don’t have dimmers, try lower wattage (or lower lumen) light bulbs.  A really important thing you can also do is stop watching TV and scrolling on your phone about an hour before bed.  So many people are in the habit of falling asleep while looking at their phones.  This is the absolute worst thing you can do for the quality of your sleep.  Sure, it might help you drop off, but you definitely aren’t going to have a restful sleep.  So give your eyes a break from all that blue light.  Let the melatonin do it’s thing.  These small changes in our environment can make a huge difference to sleep quality.  

Knowing that light has such a severely inhibitory effect on melatonin should serve as a warning about exposing our eyes to bright lights at night.  Even something that might seem as inconsequential as turning on the light to go the toilet in the middle of the night, immediately causes your lovely, sleepy-beepy, high levels of melatonin to crash to near zero.  The artificial light immediately shuts down melatonin release.  Chk! Chk! Boom!  And then of course you’ll have trouble getting back to sleep.  Melatonin naturally begins to rise early in the evening in preparation for bedtime, but it continues to increase as we sleep, well into the night.  So if you habitually get up in the middle of the night to go to the toilet, and turn on the lights every time you do, your melatonin signalling is going to be up shit creek, aka chronically disrupted.  You’ll have issues, not just with falling asleep every night, and being tired all the time, but with all the other things that melatonin regulates and protects in the body, that I mentioned earlier. You’ll forget what it feels like to feel your best.  Most of us have already forgotten. 

Even just one night sleeping in a moderately lit room has been shown to increase your sleeping heart rate, decrease heart rate variability, overstimulate the sympathetic nervous system and increase waking insulin resistance.  All very bad things.  A good guide is, if you can see your hand 30cm in front of your face while you’re in bed with the lights out, your room is too bright, and I’m sorry but you are not going to get a good night’s sleep.  David and I live in the middle of a big city.  When I’m in bed with the lights out at night, I can actually read a book by the external ambient light coming in through our floor to ceiling windows.  Even when we’re sleeping with our eyes closed, ambient light penetrates our eyelids and makes its way through our grey matter to the pineal glad, where we know it causes sleep damage.  Having this occur regularly is very harmful because sleep is supposed to be the time when the body and brain regenerate, and heal.  A lot of stuff goes on when we’re sleeping – our body temperature drops, our breathing, heart rate and blood pressure lower, our brains sort through all the information it received that day, removing what isn’t needed, our immune system kicks in to repair the body, and the brain stem temporarily paralyses our muscles.  And of course, the beautiful symphony orchestra that is our hormonal cascade has free rein to work it’s magic as we sleep. 

It seems, these days, that almost everyone is tired, all of the time.  So perhaps more of us would benefit from being more mindful of our bedroom’s light hygiene at bedtime, and ensuring we sleep in as dark a room as possible.  If installing blackout blinds or curtains isn’t practical, consider sleeping with an eye mask.  Eye masks have come a long way, and there is now a multitude of designs, so finding one that is comfortable for your face and sleeping style should be easy.  David and I recently started using them at night and it’s been an absolute game changer for me.  Actually, it’s much bigger than that.  Along with my morning light routine, it’s been life changing, and I’m not even joking.  I’m sleeping better than I have in my entire life, and waking up feeling more rested, despite working shifts.  I honestly cannot rave enough about it, because the transformation in the quality of my sleep has been simply extraordinary.  I always had this dumb kind of boastful pride about being able to sleep without curtains on our windows after a night shift, with the bright sun just streaming in.  And for many years I did myself a disservice because of that.  I feel like a bit of an idiot for waiting so long to try wearing an eyemask to bed.  But I’m well and truly on the bandwagon now, and I’d really recommend it to everyone to at least try it out and see how they feel in the morning. 

Disrupting sleep with light pollution does more than just make us tired.  It makes us ill.  It makes us ache and feel low and unmotivated.  It makes us fat, depressed and prematurely old.  It makes all of us function less than optimally.  And it doesn’t have to be that way.  But the wonderful thing about it is that you don’t have to take a pill to feel better.  You just have to go outside and let the sun shine down on you. 


  1. Thanks for that Chryss. I will try and change my regimen. Getting fat and frumpy. The youth have much more to worry about than us. On their phones the whole time; anti-social; narcissistic; don’t go outside and are even growing horns on the back of their skulls (from their head drooped and the bones of the skull having to compensate with more bone growth to carry the abnormal bend of the head). All worrying for them. Soon their offspring will be walking on all fours.

      1. Can only agree with you having got SAD (seasonal affected disorder) in London and needed UV full spectrum lamp.. Mountains are good for the sunlight though :)!

        Block out blinds are great. If you need details for Melb or France we have internal and external ones.
        Also can change doors for solid wood and pressure around the door jamb to block light and sound. This is not expensive ($500-750)

      2. Wow, I didn’t realise you experienced SAD. It’s more than just mental disorders though, as you just read. Our entire health system is dependent on sunlight and when we don’t get it we suffer.

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