Circadian Health: Part 1
“Every day, a million miracles begin at sunrise.” - Eric Jerome Dickey
Connect To The Rhythms of Nature for Optimum Health and Well-being
Have you been wondering if something is missing?
Wondering why you’ve “tried everything” to lose weight, feel less anxious, or to sleep through the night and nothing has fully worked? Or perhaps you’re living with symptoms of a chronic condition and take a long list of prescription medications, hoping for relief.
But, no matter what you do, you simply don’t feel better?
And you can’t help but wonder why - if public health initiatives AND our high tech medical care system were effective - would rates of chronic disease across all developed countries, such as the US, UK, EU, Canada, Australia and New Zealand, continue to skyrocket out of control?
I can tell you that I’ve wondered all of it, many a day.
As an integrative medicine physician and now health coach, my mission was and is to help my people understand the root cause of their symptoms and use basic approaches such as diet, exercise, and stress reduction first to bring their health back into balance before resorting to medications and investigations, as appropriate.
And, it was as frustrating for me as it was for them when their efforts didn’t produce the results we were seeking - namely an active, joyful, and productive life, free of pain and misery.
But…what if I told you that the missing piece is very likely to be right outside our doors and windows, easy to access and very inexpensive?
It’s SUNLIGHT!
Why sunlight? Because it’s a potent signal to our circadian clock cells, communicating the time of day and even the time of year, to every cell in the body.
It’s Nature’s way of orchestrating our internal mechanisms so that they’re synchronized with our environment. It’s how we - and all living beings - evolved over billions of years to beat the odds and survive and thrive.
Biological timing is of critical importance in optimizing our behavioural, physiological, and biochemical processes. That means that the normal functioning of our systems - from the molecular and cellular level, all the way up through our tissues and organs - depends upon these important signals.
And not surprisingly, research has shown that if we’re out of sync, there will be repercussions for our mental and physical health.
Circadian Rhythms - Nature’s Timekeepers
“Virtually everything in our body, from the secretion of hormones, to the preparation of digestive enzymes in the gut, to changes in blood pressure, is influenced in major ways by knowing what time of day these things will be needed. The most common misconception is that people think that they do not have to follow the rules of biology, and can just eat, drink, sleep, play, or work whenever they want.”
Humans and all living creatures have evolved to flow with the rhythms of Nature. We do that by having molecular “clocks” in our cells that respond to the daily variations in light, temperature, and humidity as the Earth makes its 24 hour rotation on its axis, and also as the seasons change as we orbit the sun.
Circadian rhythms refer to the body’s daily fluctuations that correspond to the periods of light and dark during the 24 hour day. The word circadian comes from the Latin “circa diem” - about the day.
These rhythms include our sleep-wake wake cycles, hunger and feeding times, periods of activity and rest, and internal metabolic activities - such as glucose and fat metabolism, cellular growth and repair mechanisms, hormone levels, digestion and elimination, and many more.
As mentioned above, our rhythmic functions are orchestrated by circadian “clocks,” groups of genes that respond to light cues from the external environment, triggering the manufacture of proteins that regulate time-of-day appropriate activities of metabolism and behaviour.
The master clock in our brain, the suprachiasmatic nucleus (SCN), receives information from the light hitting the backs of our eyes (retina), translates it into chemical messengers, which then relay it to other areas of the brain and to the peripheral clocks in the cells of our organs and tissues; heart, lungs, liver, pancreas, and gut.
Important note here: the photoreceptors in our eyes respond to whatever light we happen to encounter in our environment, whether it be natural daylight outdoors or artificial light indoors (or outdoors, at night). Light is light - it is electromagnetic energy that has a range of wavelengths which each contain information about the time of day, based on the angle and intensity of that light. Whether it’s natural sunlight, which contains the full spectrum of light information, or artificial electric light, having a narrower range, only blue light, for example, a message is received and transmitted to our cells and tissues, with results that may or may not be beneficial to us. I’ll go into more detail on the effects of light on our health in Part 2 of this series.
Humans and all life on Earth evolved with exposure to sunlight, which is composed of electromagnetic radiation in the infrared, visible light, and ultraviolet ranges, among others. Throughout the day, the character of this radiation varies in angle and intensity as the sun rises, makes its track across the sky, and then sets. The light-sensitive cells in our retinae (deep in the back of our eyes) respond to all of it - sending real-time information about the time of day to the brain and body as a whole.
All across the daylight hours, we have evolved to respond to each parcel of light information that shines on us - via receptors not only in our eyes, but in our skin, and even in our hair.
We now know that all of our body systems function on a circadian cycle or rhythm, in response to that light information and the setting of the clocks in their cells. For example, the timing of sleep and wakefulness, digestion and elimination, activity and rest, healing and detoxification. All of our metabolic activities respond to signals that are timed or entrained to the time of day as sensed by the master clock in response to the light information it receives.
Health problems occur when our behaviours are out of alignment with optimal system functioning, as set by the light in our environment. We’re out of balance.
As one integrative physician colleague of mine simply stated, “If you get your light right, you get your health right.”
Here’s an example: You’re watching TV (blue light) at 11 pm and you suddenly get a craving for a snack. So you go to the fridge, open it (LED light) and grab something quick. Eating late at night, when our clocks are set for sleep and our digestive system is in rest and repair mode, sends a confused message. Eating/feeding evolved as a daytime activity in humans. The digestive enzymes and hormones needed for the efficient metabolism of food aren’t switched on at night, and what results is indigestion, reflux, bloating, and potentially more fat storage than eating during the active daytime hours. Also trouble sleeping can ensue, because the brain has been confused by signalling from the digestive system that it is daytime.
Have you experienced that type of discomfort when you go to bed on a full stomach?
“Circadian neuroscience will drive the future of health and wellness.” - Beth McGroarty, Global Wellness Institute
Chronobiology is the study of circadian rhythms and Chronobiology in Medicine is the new science of using circadian rhythms to prevent and/or treat disease, and prolong life. Medical researchers are now focussing on the health effects of natural light and the timing of biological activities in the body based on circadian rhythms, with a view to developing novel therapies that mimic natural light and updated recommendations around the timing of treatments and medications.
Which, to me, begs the question … If we want to optimize our health, why wait for expensive light therapies and pharmaceuticals? Why not start synchronizing our daily activities with the light/dark cycles of Nature ASAP?
What’s involved in syncing our daily routines to the Earth’s 24 hour rhythm?
Choosing a “circadian lifestyle” means planning to synchronize your daily activities with the cycles of day and night, light and dark, through Earth’s 24 hour rotation. That could include getting up early to take in the sunrise, going outdoors to get exposure to the various angles and intensities of sunlight during the daylight hours, and soaking up the soothing red and orange hues of the sunset before getting ready for bed.
It also means coordinating daytime activities like meal and snack times, exercising and physical work, and intense cognitive or creative work with certain times of the day, and winding down as darkness approaches.
This may seem like…a LOT... but don’t worry…
Two key things you can do to get started are, first, get up and go outside either at sunrise or shortly thereafter to get the clock-setting signals of early morning light in your eyes, and second, limit and/or block artificial light (especially blue light from devices) after dark.
You’ll have to work with your chronotype - your preference for sleep and wake times. Some of us are morning people, others are night owls. This is our personal circadian rhythm, set by a combination of our genetics, daily routines, age, and other factors. There’s no question that getting up for sunrise is going to be easier for a morning person. Regardless, try to work with the environment as best you can to sync your clock to its rhythms.
There are Apps that can tell you when sunrise occurs, when it’s solar noon, and when the sun goes down and darkness falls, and many other details about the intensity and type of light where you are in the world. I use one and find it helpful, educational, and fun to follow (see Resources below).
We’ll examine circadian living in more detail later in the article. But first…
The dark side of disruptions in our circadian rhythms
“To maintain system robustness, clocks throughout the body must be synchronized, and their functions coordinated.” - Circadian Synchrony (2021)
Modern life has changed the way humans are exposed to and affected by light in our environment. We no longer rise with the sun and bed down when it sets. We travel more, work longer hours, and stay up later reading or watching screens that emit blue light, while our homes, workplaces and streets are lit by artificial electric lights after dark.
This is problematic for our sensitive circadian clocks! Artificial light at night (ALAN) sends the wrong light messages to our master clock (SCN) via our retinae (eyes) - a message that says it’s daytime when it’s night, and creates a misalignment between both the master clock and our peripheral clocks - between our brains, bodies, and the environment.
Recent evidence reports that this misalignment, the disruption of our circadian rhythm, can lead to a number of chronic conditions that further upend our internal-external balance, causing a vicious cycle of ill health.
Circadian disruption has been associated with poor sleep, especially loss of restorative deep sleep, psychiatric disorders of all types, metabolic diseases related to glucose and insulin metabolism (obesity, abnormal lipid levels, pre-diabetes and diabetes), increased risk for elevated blood pressure and cardiovascular events, neurodegenerative and autoimmune diseases, and many cancers. And poor sleep has been associated with dementia and generally accelerated aging.
Even the shift to Daylight Savings Time, the advancing of our clocks just one hour in the Spring, has been linked to higher rates of heart attacks and strokes!
Our circadian clocks regulate our cardiovascular function, glucose balance, lipid metabolism (fats and cholesterol), detoxification processes in the liver and the brain, inflammatory and immune reactions (most chronic diseases, including cancers, are underpinned by chronic inflammation), and the general smooth running of our endocrine (hormonal), digestive, elimination, reproduction and nervous systems.
Being out of sync with Mother Nature is nothing to sneeze at!
On the bright side (pun intended), any condition, symptoms, ailments, or health challenges that you may be experiencing could be very much improved by a switch to a lifestyle based on circadian rhythms.
Hot tip: Much has been researched and written about electric light at night, specifically the blue light coming off our computer screens, TVs and devices. In Part 2 of this series, we’ll take a closer look at how light, water, and magnetism interact with our circadian rhythms to promote optimum health, and we’ll talk more about light, specifically. For now, just know that bright light at night - even if dim or for just a brief minute - suppresses melatonin, the sleep hormone, and stimulates the brain to alertness at a time, after dark, when our brain cells and body tissues should be resting and repairing. Blocking blue light from your devices, especially at night, with special glasses or filters on your screens, or both (me!) can go a long way to keeping your melatonin levels in a healthy range.
Health benefits of a circadian lifestyle
Over and above the many benefits of daily sunlight, listed above, synchronizing our day-night routines with the Earth’s light-dark cycles will naturally optimize sleep duration and quality. Poor sleep has been linked with a number of chronic diseases. You could potentially be enjoying:
Improved sleep
Improved cognition (thinking ability) and alertness during the day
Improved exercise performance and general energy level
A balanced, healthy immune response
Greater success at efforts at weight management
Improved hormone balance
Reduced risk for chronic diseases
Generally improved quality of life and healthy aging
This is a relatively easy, safe, and virtually free set of health habits that most can adopt with a little forethought and planning.
The connection between sunlight and health (a sneak peak at what’s coming in Part 2!)
You may not believe this, after years of being told that sunlight is “bad for your health, will put you at risk for skin damage such as wrinkles, age spots and, worst of all, skin cancer,” but exposure to the sun’s light provides myriad health benefits.
Dr Michael Horick, endocrinologist and Vitamin D expert at Boston University Medical Center, wrote a detailed explanation of those benefits in a 2016 review article and outlined the protective and healing processes that are triggered by moderate exposure to sunlight.
(Note the word “moderate;” there is no question that overexposure to the UVB spectrum of sunlight damages DNA, and care should be taken to prevent that happening.)
Benefits of (moderate) daily exposure to sunlight
It resets our circadian clocks with light information about the time of day, synchronizing our inner workings with our environment. For example, morning sunlight advances or brings forward our night-time desire for sleep (earlier to bed), while exposure to daylight later in the day delays our bedtime clock (later to bed).
It’s our main source of vitamin D, as food sources are limited. Sunscreens and other blockers of UVB light (hats, clothing) block the trigger for our skin cells to make vitamin D. After UVB light from the sun triggers the manufacture of Vitamin D in the skin cell, it combines with its receptor (VDR) to unlock a huge number (some say around 2000) of genetic activities that keep our systems functioning smoothly and protect against disease.
It stimulates the production of melanin, which protects from damaging effects of UV radiation. Melanin, the pigment that darkens and protects our skin from damage, is an antioxidant and free radical scavenger. It’s been called “Nature’s sunscreen.”
It lowers blood pressure and reduces risk of cardiovascular events via the skin’s ability to produce nitric oxide, carbon monoxide, and other vasodilators after exposure to sunlight.
It imparts a feeling of well-being and elevates mood. Sunlight on our skin is not only warm and pleasant, it stimulates the activity of the POMC (pro-opiomelanocortin) protein, a precursor to a vast number of biologically active substances, including beta-endorphin (the same peptide that is responsible for “runner’s high”), which makes us feel good and relieves pain and discomfort. Exposure to bright light is used as a medical therapy to improve mood, sleep, and general well-being.
So let’s cut to the chase!
6 easy ways to get into sync with Nature
Rise with the sun - getting early morning light gives us the wavelengths in the infrared and red zones, before UVA and UVB have come into play when the sun gets higher in the sky. Early morning light gently alerts our SCN master clock that the day has begun and it’s time to start the metabolic engines. Take several minutes to look at the sky and soak up the light without staring directly at the sun coming over the horizon, awesome as it is. Now your master clock is reset and in sync with the new day.
Take several mini-breaks during your day and go outdoors and absorb the sun’s light (even if it’s overcast) through your eyes and skin. Dress appropriately for the weather, of course! That way your clocks will be kept in sync all through the day.
Go naked - eyes and skin, that is - but avoid turning pink! Remember that sunglasses and sunscreens block light messages to the eyes and skin. And sunscreen also blocks the UV light that stimulates Vitamin D production in the skin. It’s important to avoid sunburning and eye damage, of course, so gather your naked rays in the early morning and late day when UV light is not dominant in the sky.
Avoid or block artificial light after dark. Dim the lights at sunset and turn devices off 1-2 hours before bed. Wear blue-blocking glasses for looking at screens for longer than 10 minutes. We want to synchronize our brains and bodies to the evening light now, in preparation for sleep in darkness. So as the sun sinks in the sky where you are, and you come in from catching those last golden rays, this is the time to start dimming your indoor lights and spending less time in front of a blue-light emitting computer, device, or TV screen. If you must - and many of us work from home or have homework to do - wear blue-blocking glasses. And do your best to turn off devices at the very least 30 mins before bedtime to avoid the brain-activating, melatonin-suppressing effects of blue light, and also to let your brain wind down from the vast amount of data-processing it does in the run of a day
Get into the habit of going to bed and getting up at regular times. This may mean some negotiation with your partner, family, and even pets. It’s quite likely that different chronotypes will be living in the same house, which means someone usually has to compromise. If you truly want to optimize your health, tune into your personal preference and negotiate with your people to respect everyone’s bedtime and sleep space preferences.
Eat your meals during daylight hours and avoid late night snacking. Studies have shown that people who eat late at night are at higher risk for obesity, diabetes, and cardiovascular disease. Eating and digesting signals “daytime” to your peripheral metabolic clocks at a time when your body should be in sleep, rest, and repair mode. Carbohydrates are metabolized and stored as fat, it’s as simple as that. For metabolic health, put your fork down 3 - 4 hours before bed.
My Circadian Journey
I started aligning my daily routines with the sun’s movements early in the Spring of 2023, as I was recovering from surgery and wanted to optimize my sleep and metabolism - and get my pre-op energy back!
I always try new diet and lifestyle recommendations on myself before recommending them to clients or patients, so I can add my experience to the available science on the topic. The points listed above my current basic routine, without going getting into diet, exercise, and details about the use of light blocking technology, which I’ll cover in Part 2.
It’s a work in progress! At this point, I’m 3 months in and I’m happy to report that my sleep is slowly changing for the better. I’m a life-long super-light sleeper, so this is a big deal for me! I often become naturally sleepy mid-afternoon and take a short nap, something that I was not able to do for many years - a combination of work obligations and inability to relax. I find that timing my meals to stop eating by 6 or 7 pm has completely relieved any bedtime indigestion, and efforts at dropping the pounds I gained after surgery (eating everything in sight) are working - my body is responding!
I feel physically great and emotionally comforted and empowered by trusting in the wisdom of Nature. I want that for you, too.
Stay tuned for Part 2 and more on Circadian Lifestyles and the fascinating science around light, water, and optimizing our health, coming in August.
Tips and Resources
Carrie Bennet, a circadian health expert, is an amazing source of information! One of her tips is that missing sunrise is okay, as long as you can get outside or open a window in the early morning light, for even a few minutes. You’ll still get the clock-setting benefits of the early morning sunlight. Otherwise, try to catch the golden light at the end of the day and the sunset. Carrie shares a ton of helpful information on her Instagram @carriebwellness.
Check out the Circadian App. It’s a really useful tool to tell you when sunrise and sunset are timed in your area, and contains lots of educational information about the benefits of the various wavelengths of light in the sunlight spectrum and tips on how to live a circadian lifestyle.
Dr Satchin Panda, podcast Dhru Purohit, June 12, 2023 - Intermittent Fasting and Circadian Rhythms - a current podcast featuring a circadian scientist. Two hours of accurate, up-to-date information.
www.blockbluelight.co.uk Blue light blocking light bulbs, glasses, and more. I have personally purchased items from this company. The service is excellent and I’m loving my evening home lighting solutions!