Popular Science discusses a new study that suggests cerebrospinal fluid helps wash the brain of waste during sleep.

However, they didn’t directly measure the rate at which toxins were fleeing the scene—so this study doesn’t go so far as to prove that SWS removes the bulk of these dangerous proteins. Lewis’s team is working on that research now, along with expanding their study to include adults in their 60s and 70s, to understand how aging might affect this wash-rinse cycle.