In the study, researchers focused on a complex brain system called the glymphatic pathway. This system eliminates harmful substances that may upset the normal function of tissue and cells in the brain. The glymphatic pathway clears waste by replacing cerebrospinal fluid (CSF) with interstitial fluid (ISF). The glymphatic pathway is most effective when a person is asleepâit can eliminate potentially toxic substances from the brain, such as tau and beta-amyloid.
Researchers observed the CSF-ISF exchange in the brains of rodents on anesthesia using computer modeling and dynamic contrast magnetic resonance imaging (MRI). The experiment had the rodents in three sleeping positionsâlying on the back (supine), lying on the stomach (prone) or lying on the side (lateral). The results showed that lying on the side had a greater effect on the glymphatic system compared to the other two sleeping positions.
âOur findings bring new insight into this topic by showing it is also important what position you sleep in,â explains study co-author Dr. Maiken Nedergaard. Researchers also noted that side sleeping is the position of choice in humans and many animals.
Previous studies suggest that the brain can better remove waste products when individuals are sleeping compared to when they are awake. In a 2014 study published in the journal Neurology, researchers found that people who spend less time sleeping may increase the risk of losing brain cells and the development of dementia.
Sources for Todayâs Article:
Lee, H., et al., âThe Effect of Body Posture on Brain Glymphatic Transport,â The Journal of Neuroscience, Aug. 5, 2015; 35(31): 11034-11044, doi: 10.1523/JNEUROSCI.1625-15.2015. Â http://www.jneurosci.org/content/35/31/11034
âCould sleeping on oneâs side reduce risk of Alzheimerâs?â Medical News Today web site, Aug. 6, 2015; http://www.medicalnewstoday.com/articles/297807.php.
Gelber, R.P., et al., âAssociations of brain lesions at autopsy with polysomnography features before death,â Neurology, January 20, 2015; 84(3): 296-303, doi: 10.1212/WNL.0000000000001163, published online Dec. 10, 2014.
Murray, M., et al., The Encyclopedia of Healing Foods (New York: Atria Books, 2005), 276.