Sleeping for more than 8 hours a night could speed up ageing of major organs, scientists have suggested
Sleeping for more than eight hours a night could actually lead to organs ageing faster, scientists have suggested.
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The study, which involved biological, lifestyle and health data of more than 500,000 people, concluded that the optimum amount of sleep is actually between 6.4 and 7.8 hours per day.
Scientists from Columbia University in New York, looked for gradual changes in individual organs over time that could be used like a clock to gauge how the organ was ageing, which was then compared to changes to sleep duration.
Too many hours of sleep, and too few, appeared to speed up ageing in the brain, heart, lung, and immune system.
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It was also associated with a wide range of diseases, The Telegraph reports.
Junhao Wen, assistant professor of radiology at Columbia University Vagelos College of Physicians and Surgeons, said: "Our study shows that too little and too much sleep are associated with faster ageing in nearly every organ.
"It supports the idea that sleep is important in maintaining organ health within a coordinated brain-body network, including metabolic balance and a healthy immune system."
Ms Wen added: "Sleep is crucial to health, repairing cells and tissues, consolidating memories and removing toxins from the brain, effectively functioning as daily maintenance for physical and mental health."
According to The Sleep Council, over a third of Brits get less than six hours sleep.
As part of the new study, 23 ageing clocks were created across 17 organs or systems and compared them with sleep duration to see how it affected different parts of the body.
Among the UK Biobank participants, sleeping for fewer than six hours and longer than eight hours was associated with faster ageing.
Both short and long sleep were associated with chronic obstructive pulmonary disease, asthma and a cluster of digestive disorders, including gastritis and gastro-oesophageal reflux disease.
Meanwhile short sleep was associated with obesity, type two diabetes, hypertension, ischaemic heart disease and heart arrhythmias.
The researchers suggested that both insufficient and excessive sleep may be markers of poorer overall health across the body.
Prof Wen added: "The broad brain-body pattern is important because it tells us that sleep duration is a deeply embedded part of our entire physiology, with far-reaching implications across the body."