During deep sleep, the brain appears to wash away waste products that increase the risk for Alzheimer’s disease.
A host of new research studies suggest that this stage of sleep — when dreams are rare and the brain follows a slow, steady beat – can help reduce levels of beta-amyloid and tau, two hallmarks of the disease.
“There is something about this deep sleep that is helping protect you,” says Matthew Walker, a professor of neuroscience and psychology at the University of California, Berkeley.
The research comes after decades of observations linking poor sleep to long-term problems with memory and thinking, Walker says. “We are now learning that there is a significant relationship between sleep and dementia, particularly Alzheimer’s disease.”