Lying on a vibrating mattress while taking nitric oxide pills has shown promise for boosting the brain’s waste-disposal system. It caused the brain’s blood vessels to swell and constrict more strongly, which enhanced the glymphatic system’s clearance of a protein that accumulates during Alzheimer’s disease.

Other experiments into boosting the glymphatic system have involved ultrasound, pink noise and even intermittently inhaling high doses of carbon dioxide. “It’s important to come at this from as many angles as possible, to increase the chance of this translating to the clinic and benefitting patients,” says Christopher Brown at the University of Southampton, UK, who wasn’t involved in the latest research.