Experts have long known that too little, or too low-quality, sleep is linked with a host of health issues —from weight gain to depression to strokes. But for the first time, a group of scientists might be able to prove that poor sleep can leave brains vulnerable to Alzheimer's disease, which is increasing at alarming rates. 

Brain scientist Jeffrey Iliff, who works at the Oregon Health & Science University in Portland told NPR that sleep is valuable for brain health, particularly because your brain purges amyloid, a toxin linked to Alzheimer's, overnight, through what's called the glymphatic system. If the glymphatic system isn't able to properly clear the brain of amyloid, the researchers posit, it puts a person at a higher risk of Alzheimer's.