Restless sleep can damage the brain and increase the risk of dementia

More than 600 elderly people participated in the study. For several years, they wore special devices that tracked how they slept—how deeply, how often they woke up, and how long they stayed awake in the middle of the night. After their death, scientists analyzed the condition of their brains, especially the smallest vessels that supply it with oxygen and nutrients.

The results were very revealing: those who regularly woke up at night and slept restlessly had vascular damage in the brain. The so—called pericytes, the cells that envelop the capillaries and help regulate blood flow, were particularly affected. If the pericytes do not work, the brain begins to receive less oxygen, does a worse job of removing toxins, and the aging and inflammation processes are triggered.

Such changes cannot be felt immediately. But years later, this affects the functioning of the brain — memory deteriorates, it becomes more difficult to concentrate, and the ability to think logically decreases. The authors of the study showed that in people with disturbed sleep, cognitive abilities began to decline about 10 years before death — and this went hand in hand with vascular damage and pericyte death.

Previously, doctors already knew that poor sleep was associated with the risk of dementia, but they could not explain what exactly was wrong with the brain. Now there is a clear connection: frequent nocturnal awakenings — vascular disorders — deterioration of brain nutrition — cognitive decline.

According to neurologist and project leader Dr. Andrew Lim from the University of Toronto, this discovery may influence the approach to the treatment of age-related diseases. If you intervene in advance — for example, by treating sleep disorders, preventing sleep apnea, or making recommendations to improve the quality of night rest — you can slow down the development of dementia.

Scientists emphasize: This study does not mean that every person with restless sleep is bound to get sick. But it proves that the brain is very vulnerable to chronic sleep deprivation, especially in old age. And one of the simplest ways to keep him healthy is to get a good night’s sleep.