A new study reveals that fragmented sleep causes cellular damage to the brain’s blood vessels, providing further evidence to suggest that sleep disruption predisposes the brain to dementia.

The research, published in the journal Brain, is the first to offer cellular and molecular evidence that sleep disruption directly causes damage to brain blood vessels and blood flow.

“We found that individuals who had more fragmented sleep, such as sleeping restlessly and waking up a lot at night, had a change in their balance of pericytes—a brain blood vessel cell that plays an important role in regulating brain blood flow and the entry and exit of substances between the blood and the brain,” said Andrew Lim, principal investigator of the study and a sleep neurologist and scientist at Sunnybrook Health Sciences Centre.