Why our body clock says it's time for tea

New study shows how circadian rhythms can be rebalanced with tea

Sluggish mornings or waking up in the middle of the night could be a thing of the past if we drink more tea. So says a new study published in Critical Reviews in Food Science and Nutrition which looked at the impact of our gut bacteria on circadian rhythms – the internal body clock that controls our sleep/wake cycles.

Commenting on our internal body clock and sleep, Dr Carrie Ruxton, from the Tea Advisory Panel – www.teaadvisorypanel.com says: “Getting these cycles right has a significant bearing on our health as disruptions – for example caused by shift work or jet lag – can alter our metabolism leading to an increased risk of type 2 diabetes and obesity.

“Trillions of bacteria live in our gut – called the microbiota – and these can influence not only obesity levels and blood sugar control, but signals in the brain that make us feel sleepy or awake. Weirdly, the gut bacteria mirror our own circadian rhythms, having periods of the day when they are more, or less, metabolically active. Scientists have been able to measure this in animal models by taking samples of the short-chain fatty acids released by the bacteria when they feed.

“Looking at this latest review, in one study, subjecting study subjects to simulated jet-lag changed their gut microbiota and led to weight gain and disruptions in blood glucose levels. Transplanting a sample of gut microbiota from jet-lagged study subjects to normal germ-free study subjects resulted in the new group experiencing similar metabolic disruptions. This proves that the ill-effects of jet lag and sleep deprivation are, in part, due to the status of our gut microbiota.

“Interestingly, what we eat – and when – influences our gut microbiota, shifting the population between friendly and less friendly species. Studies show that plant compounds found naturally in tea – called polyphenols – have a striking effect on the gut microbiota, and encourage growth and activity of ‘friendly’ lactobacillus species.”

In summary, Dr Carrie Ruxton, from the Tea Advisory Panel, adds: “This fascinating, new study reveals what we eat can influence our body clocks for the better. Jet lag, late nights and shift working can take their toll but we can offset this by drinking tea which is rich in polyphenols”.