Researchers have found a link between the lack of regular deep sleep and the build-up in the brain of toxic proteins, which are thought to trigger Alzheimer's disease.
The memories of a group of adults aged between 65 and 81 were tested to see how they functioned on varying levels of sleep. They also conducted scans for beta-amyloid, a protein that forms plaques in the brain that kill off nerve cells.
People with regular sleep deprivation had the highest levels of beta-amyloid and performed poorly in memory tests.
The findings suggests sleeping well can "power cleanse" the brain, offering hope to millions of dementia patients. "Sleep is helping wash away toxic proteins at night, preventing them from building up and from potentially destroying brain cells. It's providing a power cleanse for the brain," he added.
University of California team welcomed the discovery, saying they hoped they could prevent future memory loss by treating sleep deprivation with exercise and behavioural therapy.