New studies illuminate mysterious connection between sleep and Alzheimer's disease

The exact functions of sleep remain a mystery to scientists. Although studies suggest that a healthy sleep schedule helps people regulate their emotions, perform better on cognitive tasks, and even live longer, it’s still unclear exactly what the body is doing during sleep to bring about these positive effects.

However, one recent hypothesis suggests the brain uses its downtime to run a ‘cleaning cycle’ during which it removes metabolic debris, like amyloid beta (A-beta), the main component of the sticky plaques found in the brains of people with Alzheimer’s disease. According to the hypothesis, poor sleep hinders the brain’s ability to remove A-beta and over time the plaques build up. This puts people at greater risk of developing Alzheimer’sdisease.

In 2013, scientists made an important discovery about the brain’s cleaning functions during sleep. The brain is the only organ that’s not connected to the lymphatic system, which removes waste and toxins from the body via the liver. Maiken Nedergaard, a neuroscientist at the University of Rochester in New York, thought that maybe the brain has a similar system, one scientists had yet to discover.

“If we find out that sleep problems contribute to brain amyloid—what that really says is there may be a window to intervene,” Neuroscientist Barbara Bendlin told Science News.