Sleep Position May Affect Brain Health

According to recent research, the position you sleep in may affect your brain health. The study, published in the Journal of Neuroscience, found that sleeping on your side as opposed to the back or stomach allows the brain to discard waste products more efficiently, thereby reducing the risk for neurological diseases.

Senior Woman SleepingResearchers from Stony Brook University School of Medicine in New York used rodent models to examine how sleeping affects the glymphatic system. The glymphatic system consists of pathways that run alongside vessels in the brain, which is where cerebrospinal fluid (CSF) circulates and clears out metabolic waste from the brain. This system is mostly ineffective during the day, but during sleep, the glymphatic pathways increase in size by about 60 percent, allowing more CSF to flow through at a higher rate. Amyloid and tau proteins, common waste byproducts in the brain, are cleared out during this process but can build up and contribute to neurological diseases such as Alzheimer’s.

The rodents were anesthetized and separated into three groups based on the different sleeping positions: lateral (side), prone (stomach) and supine (back). Researchers used dynamic contrast magnetic resonance imaging (MRI) and kinetic modeling to look at the exchange rates of the CSF and interstitial fluids in the glymphatic pathway in each position.

The study found that the lateral position correlated with the most efficient glymphatic transport. Rodents in the lateral position cleared out amyloid beta 25 percent more effectively than rodents in the supine or prone positions. Clearing amyloid beta out the brain prevents build-up and the formation of plaques, one of the hallmarks of Alzheimer’s disease.

The lateral position could be more effective at clearing out waste because it allows CSF to flow throughout all of the brain’s crevices. The supine and prone positions may cause CSF to exit the brain prematurely and flow to other places, such as the spinal cord.

Scientists have known for some time that sleeping gives the brain time to clear out waste that has built up during the day, but this new finding adds another dimension by highlighting the importance of sleep posture. Interestingly, sleeping on our sides in the fetal position is the most common sleeping position in humans and most animals. Learning more about when the glymphatic pathway turns on and works most efficiently could help researchers discover more effective ways to clear waste out of the brain.

Until this research is proven in humans, the most important takeaway is that the glymphatic pathway is most effective at night, emphasizing the importance of a good night’s sleep. Be proactive about your brain health and get the recommended seven to eight hours of sleep each night. To learn about other non-pharmacological ways to promote brain health, visit