Sleep position could affect dementia risk, new research suggests

A University of Rochester study reports that lateral (side) sleeping was associated with roughly 25% more efficient clearance of brain waste on MRI compared with back or stomach positions, and links this effect to the brain's glymphatic system and proteins tied to Alzheimer's disease.

New research links sleep position to how efficiently the brain clears metabolic waste during sleep. Scientists describe a cleanup process called the glymphatic system, which moves cerebrospinal fluid through brain tissue during deep sleep. Researchers at the University of Rochester reported that lateral (side) sleeping showed about 25% more efficient clearance of proteins associated with Alzheimer's disease compared with back or stomach positions. The work builds on earlier discoveries of the glymphatic system and connects posture to fluid flow in the brain. What the studies report: - The glymphatic system circulates cerebrospinal fluid through brain tissue in sleep and helps clear metabolic waste, including amyloid-beta proteins. - A University of Rochester study using MRI data found lateral (side) sleep was roughly 25% more efficient at clearing waste than back or stomach positions. - The research drew on both animal models and human subjects and linked position to differences in cerebrospinal fluid flow through brain drainage channels. - Authors and summaries emphasize this finding is not a cure or guarantee and is one factor among many that relate to brain health. - The reporting notes other health considerations—such as reflux, certain cardiac concerns and sleep apnea—that can influence which sleep position is preferable for an individual. Summary: The research indicates that sleep position may influence the brain's nightly waste-clearance processes and could be one factor among others tied to dementia risk. How these findings will affect long-term outcomes or clinical guidance is undetermined at this time.