We’ve all heard too many times to count that we’re better off getting plenty of sleep than just a bare minimum. But do you know why?
A very interesting article penned by James Gallagher, Health and Sciences reporter for the BBC, explained the answer in layman’s terms I felt compelled to share.
The short answer is that sleep cleans the brain of the immersive toxins that build up throughout our conscious hours. The busier we are and more the wheels churn, the more valuable a good night’s sleep provides. Depriving ourselves of adequate sleep prevents these toxins from fully flushing — which means we wake up the next day not fully recharged.
Researchers studying brain cell functions report that this “waste removal system” is one of the fundamental reasons people — as well as animals — require sleep.
Gallagher wrote that study results indicate brain cells shrink during sleep, which open up gaps between neurons. These gaps allow fluid to “wash” the brain clean. This processes cleanses and refreshes our brains, fully preparing them for the next day’s activities.
He also adds that research suggests that failing to clear away some of these built-up toxic proteins quite possibly plays a role in brain disorders. Our learning point is to do our best to prevent them from building up.
One big question for sleep researchers is, “Why do animals sleep at all when it leaves them vulnerable to predators?” Research points to the answer being that they must in order to have full functional brain capacity to fully act, react, and survive.
University of Rochester Medical Centre researcher Dr. Maiken Nedergaard believes that this type of necessary “housework” may be one of the key reasons for sleep with both humans and animals.
“The brain only has limited energy at its disposal,” she said. “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.”
Dr. Nedergaard’s team’s findings build on last year’s discovery that the brain’s own network of plumbing pipes (known as the “glymphatic system”) carry waste material out of the brain. This system, based upon findings from imaging the brains of mice, is ten times more active when the mice are asleep than awake.
Brain cells, probably those which keep nerve cells alive, shrink during sleep, which increases the size of the gaps between brain tissue. Larger gaps allow more fluid to be pumped in, which creates greater efficiency for washing the toxins away.
Dr. Nedergaard went on to say that this process is a vital function for staying alive – but one that does not appear possible while the mind is awake.
She added, “This is purely speculation, but it looks like the brain is losing a lot of energy when pumping water across the brain and that is probably incompatible with processing information.”
The cleansing seems a necessary activity — but one that must take place when the brain is at rest.
Dr. Nedergaard added that the true significance of these findings will be known only after human studies, but similar experiments using an MRI machine should be relatively easy.
Commenting on her work was sleep expert Dr. Neil Stanley, who said, “This is a very interesting study that shows sleep is essential downtime to do some housekeeping to flush out neurotoxins.
“There is good data (currently) on memory and learning — the psychological reason for sleep — but this is the actual physical and chemical reason for sleep. Something is happening, which is important.”
Many conditions which lead to the loss of brain cells, such as Alzheimer’s or Parkinson’s disease, are characterized by the build-up of damaged proteins in the brain. These recent research findings suggest that problems with the brain’s cleaning mechanism may contribute to such diseases.
But before drawing absolute conclusions, all agree additional research is needed.
As our lives and careers unfold, technology dependence and living an oversubscribed life can accelerate (at times) relentless brain activity. We have already rising frequencies of chronic abuse leading to addiction problems, shorter attention spans, and restlessness.
But as science underscores why a good night’s sleep is important, we should all take heed protect our nightly eight hours.
Few will debate that we feel better after a good night’s sleep than a poor one. Now you know why.
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