It’s been known for millennia that the human body accumulates waste as a result of day-to-day functioning, but it’s now recognized that the awake, active brain also builds up waste that negatively affects neural function if not removed.

Thankfully, it was recently discovered that the brain has a garbage removal mechanism.

“The glymphatic system is a brain-wide network of perivascular spaces that facilitates the clearance of waste products from the brain during sleep,” Jeffrey Iliff, PhD, professor in the Department of Psychiatry and Behavioral Sciences/Department of Neurology, University of Washington School of Medicine, and researcher at the VA Puget Sound, Seattle, told Medscape Medical News.

This system “serves a similar function in the brain as the lymphatic system does in the rest of the body,” Iliff continued.

As a medical student he learned about the cerebrospinal fluid (CSF) surrounding the brain “we thought of it as an inert fluid with a primarily protective purpose, functioning as a sort of shock absorber,” he said. The reality is far more complex, and it’s now known that the CSF plays “an important part in cleansing brain tissue by removing waste products and conveying nutrients throughout brain tissue.”