Deep, non-REM sleep helps people's brains to wash away toxic proteins and waste, a new study found, reinforcing the link between sleep deprivation, aging and Alzheimer's disease.
The study, out Wednesday in the journal "Science Advances," found that theslow and consistent brain activity experienced during deep, non-REM sleep is ideal for the brain's glymphatic system, which effectively "cleans" the brain of toxic proteinslike beta amyloid and tau.
Because the build up of proteins in the brain – including tau – have been linked to Alzheimer's disease and dementia, researchers say the study further underscores the link between poor sleep and dementia. It also notes that sleep becomes lighter and more disrupted as people age.
"Sleep is critical to the function of the brain's waste removal system and this study shows that the deeper the sleep the better,"said Maiken Nedergaard, co-director of the Center for Translational Neuromedicine at the University of Rochester Medical Center and lead author of the study. "These findings also add to the increasingly clear evidence that quality of sleep or sleep deprivation can predict the onset of Alzheimer's and dementia."