Why Circadian Rhythms Matter

Otherwise known as internal body clocks, circadian rhythms are 24-hour cycles that govern many important functions in our bodies. One of those rhythms is the sleep/wake cycle which regulates a consistent pattern of alertness and sleepiness. Others include our biological clock and eating habits and digestion.

What happens if your circadian rhythm is disrupted?

If your sleep/wake or light/dark rhythm is out of alignment, you may notice symptoms such as feeling very sleepy in the daytime, decreased alertness and issues with your memory. If this rhythm continues to be disrupted, the body’s systems won’t function optimally and it could lead to other chronic health conditions such as obesity, diabetes and depression.

While most of us will experience minor disruptions to this natural rhythm, whether it’s caused by jet lag after a long trip or a bout of illness that prevents us from sleeping, some people are more susceptible to long term disruptions and the damage this can cause. If you suffer from chronic insomnia or regularly undertake shift work that means you’re awake during the night and asleep during the day, studies show that you’re 40% more likely to be at risk of depression and anxiety.

How to realign circadian rhythms

One theory on how to overcome the tendency for depression if you are a shift worker has come to light recently, with a 2022 study noting that shift workers who only ate during daytime hours regardless of their working hours experienced significantly less mood vulnerability than those who ate during both day and night-time hours during a night shift.

Other approaches to try include sticking to a regular sleep schedule as much as possible (even on days off and weekends) and minimising caffeine intake in the hours preceding bed. And if you are working shifts, the general advice along with all the above is to adjust your exposure to light according to your own day/night pattern, which means using bright light at work and wearing dark sunglasses as you’re leaving to avoid too much exposure to daylight when you’re about to head to bed.