You’ve heard of sleeping on the wrong side of the bed, but did you know you could be sleeping on the wrong side of your body? Sleeping on your side—either one—is way more effective in removing waste matter from your brain and reducing your risk of developing Alzheimer’s, Parkinson’s, and other neurological diseases (compared to sleeping on your back or stomach), according to research from Stony Brook University.
While you sleep, a complex system in your brain called the glymphatic pathway clears away harmful chemicals that are produced during the day—much like how your lymphatic system clears any waste from your organs—by pumping what scientists call cerebrospinal fluid through the brain and exchanging it with what's called interstitial fluid (don't worry: there won't be a vocab quiz at the end of the article.)
In this study, researchers used MRI machines to examine the glymphatic pathway in rodents’ brains as they slept in three different positions—laterally (side), prone (down), and supine (up). Time and time again, the glymphatic transport (aka the cleaning out of your brain) was most efficient when the rodents slept on their side. This is good news for us, since side-sleeping is already the most common sleep position in humans and many other animals, say researchers.
"The study therefore adds further support to the concept that sleep subserves a distinct biological function of sleep and that is to 'clean up' the mess that accumulates while we are awake,” said Maiken Nedergaard, PhD, one of the study’s researchers, in a release.
Though testing with MRI on humans has yet to be done, the researchers are confident these findings are a step toward eliminating risk factors in neurological illnesses and disorders.