Circadian solutions for better sleep

Restorative sleep has never been more important – or more elusive, as anxiety around Covid-19 has us tossing and turning. But have we been searching for ZZZs in all the wrong places? Forget milky drinks and weighted blankets – research now suggests what we need most is to support our circadian health.

- GLYNIS HORNING

Circadian rhythms’ might sound like an ’80s synth-pop band, but they’re key to our biology and our health. They’re the physical, mental, and behavioral changes all organisms, including humans, have evolved to respond to – our internal body clocks controlling virtually every biological system, from our sleeping and waking cycles to mood and performance levels, and metabolic, reproductive and immune systems. And those immune systems have never been more important than in the war on Covid-19.

To keep our immunity strong and be in the best physical and mental shape to fight infection, most of us need seven to eight hours of sleep a night. ‘A few people can get by with five hours and wake to feel refreshed, which is what counts,’ says Michelle Baker, a Durban-based clinical psychologist with a special interest in sleep. But regularly getting less than five hours has been linked to a raft of ills, from increased inflammation, high blood pressure and insulin resistance to weight gain, cardiovascular disease, impaired blood sugar regulation, and the big one right now – impaired immunity.

The impact of poor sleep on immunity has been shown in several studies, such as one done last year at the University of California, which found that people who got less than six hours of sleep a night were four times more at risk of catching a cold when exposed to the virus than those who had seven hours or more. ‘Another study showed an increased risk of catching pneumonia with less than five hours of sleep,’ says Dr. Alison Bentley, who runs a sleep therapy clinic at the Wits University Donald Gordon Medical Centre.