Circadian rhythms

MASTER YOUR BODY CLOCK, GET IN SYNC WITH THE SEASONS AND LEARN HOW TO THRIVE, THROUGH WINTER AND BEYOND

Trying to shake a leg, or at least feel vaguely human, on a cold, winter’s morning has never been life’s easiest goal. Once we’ve dragged ourselves out of bed and sleepwalked to our desks – in the office or at home – the short winter days do their vanishing act on us. Before we know it, we’re cranking up the lights as mid-afternoon darkness descends, rummaging around for biscuits and putting that park walk on ice as we inch longingly towards the deep rest of a weekend lie-in.

While a strong cup of coffee can jolt us to our senses, the long-term tonic to living and thriving through the seasons might lie closer than we think: in our own innate body clocks, which, physiologically, govern nearly every second of our sleeping and waking day. Circadian rhythms, which topped the list of trends at the 2020 Global Wellness Summit, are the mental, physical and behavioural changes that follow a roughly 24hr cycle. These cycles are intricately linked to the body’s master clock or SCN (suprachiasmatic nucleus), a cluster of cells located in the brain’s hypothalamus which acts a bit like Grandfather Time, syncing the millions of tiny clocks that tick away in most of our cells. And we’re not alone. Human body clocks are part of an earth-wide orchestra of circadian rhythms, found in animals, plants and even the tiniest of microbes, all working in harmony with the ever-changing seasons.

SEEING THE LIGHT

What most excites scientists, with research gaining pace in the last 50 years, is the master clock’s ability to anticipate the light, rather than react to it; we know when to eat, sleep and exercise in accordance with the rising and setting of the sun. It’s why we feel so off kilter when the clocks go back or, worse, after a long-haul flight – the brain is syncing up to changing light levels while our taste receptors are craving a bowl of midnight Weetabix. Because circadian rhythms influence everything from our sleep patterns and hormone releases to body temperature and changes in blood pressure, understanding how to work with our body clocks rather than against them could provide a simple yet radical toolkit for greater wellbeing through the seasons, helping to ward off anxiety, SAD (Seasonal Affective Disorder), diabetes, dementia and obesity.

‘The stakes have never been higher,’ writes leading circadian rhythm expert, Dr Satchin Panda, in his book

The Circadian Code (Vermilion), who believes the roots of society’s rise in chronic diseases stem from humans

living out of step with our primordial selves. ‘Our modern lifestyle, in which we spend most of our time indoors looking at bright screens and turning on bright lights at night, activates melanopsin at the wrong time of day and night, which then disrupts our circadian rhythm and reduces the production of the sleep hormone, melatonin; as a result we cannot get restorative sleep.’

While screens are lighting up our down time, it’s our brain’s master clock, perhaps most crucially, that isn’t receiving enough natural daylight to keep our systems »