by Nina

Sun Behind Clouds by Melina Meza

One of the worst fears I think we all share about getting older is of developing dementia. Just recently I had a long phone conversation with a woman who is trying to deal with a mother in the early stages of Alzheimer’s Disease, and it was just so sad. I had some advice for her, but no solutions, of course. Then I heard a news piece on NPR “Brains Sweep Themselves Clean of Toxins During Sleep”  that gave me  glimmer of hope.

For a very long time, scientists have been trying to figure out the purpose of sleep. Now, a recent study “Sleep Drives Metabolite Clearance from the Adult Brain”  by University of Rochester researchers that was published in Science Magazine proposed a fascinating new theory about sleep. The researchers discovered that while you are asleep, your brain clears out harmful toxins! During sleep there is a dramatic increase in flow of cerebrospinal fluid in your brain, and this washes away the toxic waste proteins that built up in your brain when you were awake. Professor of Neurosurgery and an author of the study, Dr. Maiken Nedergaard, said in the NPR interview, “It’s like a dishwasher.”

The researchers said that this cleansing process may reduce the risk of Alzheimer’s because the waste proteins being washed away are toxic to brain cells. This potentially explains why it is hard to think clearly after you’ve had a sleepless night and why prolonged lack of sleep can actually kill people and other animals. According to the researchers, this cleansing of waste products during sleep maybe be the very reason we need to sleep! 

“Thus, the restorative function of sleep may be a consequence of the enhanced removal of potentially neurotoxic waste products that accumulate in the awake central nervous system.” Lulu Xie, et al.

Alzheimer’s Disease researchers say this research could help explain a number of recent findings on the relationship between sleep and Alzheimer’s. Dr. Randall Bateman, Professor of Neurology  at Washington University, said the following about beta amyloid (the main component of certain deposits found in the brains of patients with Alzheimer’s Disease):

“Beta amyloid concentrations continue to increase while a person is awake. And then after people go to sleep that concentration of beta amyloid decreases. This report provides a beautiful mechanism by which this may be happening.”

The researchers discovered the cleaning process when they studied the brains of mice as they slept. Dr. Nedergaard said that during sleep the system that circulates cerebrospinal fluid through the brain and nervous system was “pumping fluid into the brain and removing fluid from the brain in a very rapid pace.” In addition, when the mice went to sleep, their brain cells shrank, which made it easier for the fluid to circulate. Then, when the mice woke up, their brain cells enlarged again and the circulation of fluid slowed dramatically.

The researchers speculated that the reason your brain doesn’t clean itself while you are awake is because this type of cleaning uses a lot of energy. So it’s probably not possible for your brain to clean itself while at the same time it is keeping you aware of your surrounding and allowing you to move, talk, and so on. 

Now we already know that getting enough sleep is vital for our physical and mental health, but if the purpose of sleep is to wash our brains clean of toxins, getting enough sleep may also be a key to keeping your brain healthy and preventing Alzheimer’s Disease as you age.

But what does all this have to do with yoga? Well, if you’re having trouble sleeping, yoga can help with that. Because insomnia is so often related to stress, yoga’s stress management techniques can help you quiet your nervous system so you fall asleep more quickly and sleep more soundly. For  information on how yoga can help you sleep better, see Yoga for Insomnia, Part 1, Day to Night: Yoga for Better Sleep, and Five Tips for Better Sleep. The Supported Inverted poses I wrote about recently (see All About Supported Inversions) are poses that I’ve found particularly helpful.

We’re so careful here at YFHA not to make any false promises and of course as this research is new, we can’t promise that getting enough sleep will definitely make a difference for you. But encouraging you to get a good night’s sleep can’t be harmful in any way, and if this gives you more motivation to practice stress management techniques, which are helpful for preventing a whole host of health problems, we’re doing you a favor. And if you’d like to add an additional practices to encourage brain health, start meditating on a regular basis (see Meditation and Brain Strength) and keep practicing your yoga asanas (see Yoga for Brain Health?). 

 

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