There is mounting evidence that missing out on sleep may contribute to Alzheimer’s.

During deep, slow-wave sleep, brain cells shrink slightly to allow fluid from around the brain to flow through and help clean out the build-up of waste from cellular processes. Our brain doesn’t have lymphatic vessels to drain away “gunk” like the rest of the body. After observing this phenomenon in mice, researchers at the University of Rochester Medical Center in 2013 postulated that this brain cleaning mechanisms is one of the primary reasons we sleep. This year scientists at UC Berkeley’s Sleep and Neuroimaging Lab have uncovered further evidence in people that insufficient deep sleep may leave their brains vulnerable to dementia and memory loss.