Circadian Health

Judith Boyce
Written by Judith Boyce

Re-establishing our Connection to the Rhythms of Nature

Every day, a million miracles begin at sunrise.

Eric Jerome Dickey

Have you been wondering if something is missing?

Wondering why you’ve tried everything to lose weight, feel less anxious, or 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 medications that are meant to help, but…. 

…no matter what you do, you simply don’t feel better?

And you find yourself wondering why – if individual and public health-based efforts at health and wellness were effective – would approximately one-half of the men and women over 65 in the UK be suffering with two or more chronic disease conditions, with the numbers predicted to rise to 67% by 2035? And, those numbers are similar across all developed countries, such as the US, Canada, Australia and New Zealand, and much of the EU.

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 is to help 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. 

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 could be right outside our doors and windows, easy to access and very inexpensive?

If you guessed SUNLIGHT, you would be right!

Why sunlight? Because it’s the most potent signal to our circadian clock cells, effectively communicating the time of day and even the time of year!

It’s Nature’s way of orchestrating our internal and external activities so that they’re synchronised 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 optimising our behavioural, physiological, and biochemical processes, which means the normal functioning of our systems from the molecular and cellular level, all the way up through our tissues and organs, to us as walking, talking humans. 

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, are 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.

Clifford Saper, MD, PhD – Harvard Medical School.

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 information, and relays 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.

It’s important here to note that 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’s 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, a message is received and transmitted to our cells and tissues, with results that may or may not be beneficial to us.

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 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 their clocks. For example, sleeping and waking, 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.

A basic example would be eating late at night, when our clocks are set for sleep and our digestive system is in rest and repair mode. Eating/feeding is a daytime activity in humans. The digestive enzymes and hormones needed for efficient metabolism of food aren’t switched on at night, and what results is indigestion, reflux, and bloating. And insomnia! Have you experienced that type of discomfort when you go to bed on a full stomach? 

One colleague of mine stated simply, “If you get your light right, you get your health right.” 

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 begs the question… If we want to optimise our health, why wait for expensive pharmaceuticals and light therapies? Why not start synchronising our daily activities with the light/dark cycles of Nature ASAP?


Main photo by Pixabay