What if I told you that there is one simple way to clean your brain of harmful toxins, significantly improve your memory, reduce your reaction time, and increase general brain function? Some recent research has led scientists to conclude that there really is one simple trick to achieving all the above, and it’s not a pill. It’s sleep.
I think that most people know that sleep is healthy for you, but I think few appreciate just how vital it is. Research on rats has shown that prolonged sleep deprivation can cause severe pathology and death (1). For those with epilepsy, seizures occur more frequently if the patient has been deprived of REM* sleep (2). One benefit of sleep that I recently became aware of is that during sleep, your brain goes through a cleaning process, literally flushing the brain of toxins that build up during the day.
So how does this detoxifying process work? Researchers have discovered that when mice sleep their brain cells (neurons) shrink (3). This shrinking allows for more cerebrospinal fluid to flow through the brain, washing away harmful waste proteins that build up between cells. When the mouse wakes up, their brain cells swell back to their normal size and the flow of cerebrospinal fluid slows to a trickle.
One significant implication of this research is that this mechanism could be our brains’ natural defense again Alzheimer’s. Levels of a protein called beta amyloid, which accumulates on neurons in sticky plaques associated with dementia, gradually increase during the day. After a full night of sleep, levels of beta amyloid are greatly reduced, likely through the detox process described above. This theory is supported by the fact that diseases associated with dementia, like Alzheimer’s, are positively correlated with sleep disorders (4).
Not only is our brain cleaning itself out while we sleep, it may also be more active during our sleeping hours than previously assumed. Before scientists had access to today’s brain-imaging techniques, we assumed that our brain “turns off” when we go to sleep. On the contrary, although our consciousness is dulled during sleep, the brain is still roughly 80% activated, and therefore still capable of elaborate information processing (5). Instead of thinking of the brain as powered down during sleep, think of sleep as the brain switching gears. During REM sleep, when most intense dreams occur, your brain generates stimulus so vivid that it becomes difficult to differentiate between the electrical signals of a sleeping brain and a dreaming brain (5).
Do your brain a favor, and get some sleep. The known benefits, of which I’ve just scratched the surface of here, are countless, and scientists are still working on finding more.
*REM stands for rapid eye movement. REM sleep is part of your natural sleep cycle, and is characterized by intensely hallucinatory dreams. REM sleep typically makes up about 20% of your night.
- A. Rechtschaffen, M. A. Gilliland, B. M. Bergmann, J. B. Winter, Physiological correlates of prolonged sleep deprivation in rats. Science. 221, 182–184 (1983).
- B. A. Malow, Sleep Deprivation and Epilepsy. Epilepsy Curr. 4, 193–195 (2004).
- L. Xie et al., Sleep Drives Metabolite Clearance from the Adult Brain. Science. 342, 373–377 (2013).
- Brains Sweep Themselves Clean Of Toxins During Sleep. NPR.org, (available at http://www.npr.org/sections/health-shots/2013/10/18/236211811/brains-sweep-themselves-clean-of-toxins-during-sleep).
- J. A. Hobson, Sleep is of the brain, by the brain and for the brain. Nature. 437, 1254–1256 (2005).