Poor sleep accelerates brain aging

In the new work, experts studied the data of 27.5 thousand middle-aged and elderly people from the UK Biobank database. All participants had an MRI scan of their brains, and then, using machine learning, the scientists estimated the biological age of the brain — that is, how much older or younger it looks relative to the passport age.

Sleep quality was assessed by several parameters at once: the tendency to be a morning person or an owl, the duration of sleep, the presence of insomnia, snoring and daytime sleepiness. Each participant received points: the higher the amount, the healthier the sleep.

It turned out that the difference between the biological and chronological age of the brain increased by about six months for each lost score of healthy sleep. On average, the brains of people with serious sleep problems looked a year older than their real age.

To understand the mechanisms, the researchers analyzed the level of chronic low-level inflammation in the body. It turned out to be associated with accelerated brain aging and could explain about 10% of this relationship. Scientists suggest that the brain’s active cleansing system during sleep, as well as the effect of sleep on heart and vascular health, may also play an important role.

“Our results show that poor sleep is directly related to accelerated brain aging,” says study author Abigail Dove. “But the most important thing is that sleep is a factor that we can influence. By improving sleep quality, it may be possible to slow down brain aging and reduce the risk of cognitive decline.”