A study published Oct 17 in the journal Science reveals one more reason to catch some zzzs. Previous studies have proven that the brain is active during sleep, sorting through information and organizing the events of the day. A new, landmark study, however, suggests that the effects of sleep on the brain extend far beyond processing memories—the brain may actually flush toxins while you get some much-needed shuteye!
Sleep and the Brain
Researchers at the University of Rochester Medical Center for Translational Neuromedicine had already determined in prior studies that the lymphatic system, responsible for removing harmful wastes from the body, doesn’t cross the blood-brain barrier—the protective gateway to the brain. Instead, the brain employs the glymphatic system to pump cerebral spinal fluid from the brain and into the circulatory system, where it eventually reaches the liver and is disposed from the body.
Hoping to uncover just how the brain utilizes the glymphatic system to eliminate accumulated toxins during sleep, scientists used new imaging technologies to investigate the brains of mice. Researchers discovered that a mouse’s brain is 10 times more active during sleep! They postulate that the brain’s glymphatic system requires more energy than can be accessed during the day when the brain is busy taking in information. It is during sleep then, that the brain activates its waste removal system and clears away toxins associated with degenerative brain diseases such as Alzheimer’s.
The study’s lead author, Dr. Maiken Nedergaard, co-director of the University of Rochester Medical Center for Translational Neuromedicine, explained in a university news release: “The brain only has limited energy at its disposal and it appears that it must choose between two different functional states—awake and aware or asleep and cleaning up. You can think of it like having a house party. You can either entertain the guests or clean up the house, but you can’t really do both at the same time.”
The study also showed that our brains get rid of more amyloid-beta—the plague-building protein associated with Alzheimer’s—when asleep. During sleep, our brain cells narrow up to 60%, thereby creating more space between cells so that waste removal is optimized.
A Sleep Deprived Brain
A sleep-deprived brain is not only fatigued and unfocused, but is also full of toxic proteins that promote neurodegenerative disorders. The link between sleep and your brain is undeniable, and you owe it to your mental and physical health to give your body the restoration it needs.
While researchers need to build upon this preliminary evidence of the effects of sleep on the brain, the study could hold the key for treating brain disorders.
Nedergaard is hopeful, saying, “Understanding precisely how and when the brain activates the glymphatic system and clears waste is a critical first step in efforts to potentially modulate this system and make it work more efficiently.”