A British study concludes that the risk of developing chronic diseases increases significantly below five hours of sleep per night after the age of 50.

Sleeping less than five hours means exposing yourself to a significant deterioration in your health from the age of 50. If it is not necessarily dangerous to sleep a little less (or a little more) than the seven to eight hours recommended for adults by specialists, going below the threshold of five hours is associated with an increased development of diseases. to the conclusions of several researchers published in the American scientific journal Plos Medicine.

People who sleep less than five hours a night are 30% more likely to develop at least two chronic diseases after age 50 compared to those who sleep between seven and eight hours. The most frequently declared diseases are the various forms of cancer, diabetes and cardiovascular diseases.

Up to 40% higher risk at age 70

This proportion of 30% is an average of the results obtained at ages 50, 60 and 70, stored in the database. In detail, people aged 50 who slept an average of less than five hours a night were 25% more likely to develop chronic diseases compared to people of the same age who slept between seven and eight hours a night. For 60-year-olds, the excess risk is 32%, and it rises to 40% at the age of 70.

People who sleep longer than eight hours also have a higher risk of developing chronic diseases – especially because their sleep may be of poorer quality – but this proportion is lower than for those who sleep less than five hours.

The researchers who conducted the study point out that the age populations were compared without other risk factors such as smoking, poor nutrition, low physical exercise or even genetic predispositions being fairly represented. Another limitation: the data obtained are based on the statements of the subjects without further checks and analyzes by scientists.

These findings are based on health and sleep data for almost 8,000 Britons, grouped into the Whitehall II cohort. They were collected over 25 years, stored and analyzed by researchers. The data collected from this cohort relate to individuals’ health and socioeconomic profiles in an attempt to establish links between the two.

The importance of chronic disease surveillance

Researchers highlight the need to understand the link between sleep duration and chronic diseases in a context where the latter weighs more and more in the health costs of Western countries, and this proportion should increase further in the coming years, according to French health insurance forecasts.

The institution explains that out of 168 billion spent on the care of more than 66 million patients in 2020, 104 billion had been for chronic pathologies, or 62%. A constantly increasing share since at least 2015.