Infections: Sleep deprivation harms the immune system

Researchers at the University of Washington have found that chronic sleep deprivation reduces immune defenses. A study of twins.

Short nights double the risk of a driving accident, they also harm your heart or promote weight gain. To this already long list, this Sunday is added new harmful effects of lack of sleep. Gastroenteritis, flu, if you succumbed to these viruses this winter it may still be Morpheus’ fault.

In any case, this is what a study by the University of Washington (United States) conducted on 11 pairs of identical twins. This particularity is a real plus which allows, among other things, to exclude all genetic predispositions.

7h minimum sleep recommended

Led by Dr Nathaniel Fletcher Watson, Co-Director of the Sleep Medicine Center at Harborview, the team took blood samples from all the volunteers, each time having different sleep times. “The sample’s average 24-hour sleep duration was 439.2 minutes, or just over 7 hours per night,” the authors say in the medical journal Sleep.

Scientists also specify that the average difference in sleep duration among pairs of twins was 64.4 minutes. “The results show that the immune system works better when it gets enough sleep. In the context of seasonal epidemics, seven or more hours of sleep are therefore recommended for optimal health, ”says Dr Watson. Here, the twin who had a shorter sleep duration ended up with a depressed immune system, compared to his brother or sister.

Rhinoviruses like little sleepers

“A lot of existing data has already shown that reducing sleep – for a limited time in the lab – can increase inflammatory markers and activate immune cells,” added study co-author Dr Sina Gharib of the University of Washington. “This study, conducted for the first time in real conditions, showed that disturbed sleep interferes with white blood cells (leukocytes), which are essential for maintaining our immunity,” he analyzes.

The researchers therefore conclude that these results are consistent with previous studies showing that people deprived of sleep who receive a vaccine have a poorer immune response. Ditto when they are exposed to a rhinovirus.

An American research published in 2015 had, it is true, already shown that people who sleep less than 6 hours per night are 4 times more likely to catch a cold than people who sleep more than 7 hours.

Towards generalized sleep deprivation

Finally, these researchers also note that Americans sleep up to two hours less in recent years, and that about a third of the working population sleeps less than six hours per night in America.

“In modern society, the importance of sleep has diminished. Particularly because of the ubiquitous technology. This results in the widespread privatization of sleep, which is dangerous for the health and well-being of individuals, ”the team concludes..