Picture a fish tank without a filter. Before too long, sludge and slime build up, and the fish die.
Your brain without sleep is like a fish tank without a filter.
Until the last few years, scientists really didn’t understand just how your brain cleans up after itself. Now, they do.
One of the things they know is that, without enough good, restful sleep, you end up with a “dirty brain” that could lead to Alzheimer’s and Parkinson’s diseases.
How your brain gets “dirty”
Like any other part of the body, the brain uses energy to do its job. Anytime energy is used, there are waste products.
While we are awake, the normal workings of the central nervous system produces proteins as by-products. These proteins are harmful to the brain…
Among the best-known of these are beta-amyloid and tau proteins. It is believed that an abnormal accumulation of these triggers the symptoms of Alzheimer’s disease.
The glymphatic system: Waste drainage for your brain
Scientists have long known about the body’s lymphatic system, which drains toxins from every organ of your body. Except your brain.
Until recently, we assumed the brain got rid of its toxins by breaking them down and recycling them within individual cells.
To Dr. Maiken Nedergaard, a biologist and professor of neurosurgery at the University of Rochester, that just didn’t make sense.
“The brain is too busy to recycle all that energy,” she thought.
In her studies with mice, she found that, in fact, their brains used specific pathways to filter waste that closely resembled the mechanisms of the lymphatic system.
This waste elimination system is our glymphatic system. The name is a combination of “glial cells” and “lymphatic system.”
Glial cells are brain cells that protect neurons. They also control the flow of waste-eliminating fluid through the glymphatic system by shrinking or swelling.
Flushing our system while we sleep
Next, Dr. Nedergaard wanted to find out exactly when the brain did this work.
“We thought this cleaning process would require tremendous energy,” she said. “And so, we asked, maybe this is something we do when we’re sleeping, when the brain is really not processing information.”
Sure enough, that is exactly what happens.
While we sleep, large amounts of cerebrospinal fluid flood through our brains, washing away brain-toxic proteins that have accumulated during the day.
“It’s like a dishwasher,” says Dr. Nedergaard.
During sleep, the volume of the fluid-filled spaces around brain cells, or interstitial space, expands by 40 to 60 percent. It’s like the hose opens wide, and fluid rushes through, taking toxic proteins with it at an enormous rate.
When the system breaks down
Research points to a link between the health of our glymphatic system and the prevention of Alzheimer’s and Parkinson’s diseases.
- Jeff Iliff, a researcher at Oregon Health and Science University, found evidence that aquaporin-4, a key protein in glymphatic vessels, breaks down in the brains of people with Alzheimer’s.
- Beta amyloid proteins have also been connected with dementia in Parkinson’s disease
Protect your sleep, protect your brain
We know that sleep can become more elusive as we get older. Here are some tips for improving your sleep.
By the way, it’s been shown that your glymphatic system works best when you sleep on your side. Interestingly, this is also the most popular sleep position. Maybe it evolved as our body’s way of ensuring that we clean our brains each night.
If you’re not a side sleeper, no worries. But maybe you’ll want to try training your body to be comfortable in that position. Regardless, a good night of sleep will go a long way toward protecting your brain.
Editor’s note: The glial cells, mentioned above, are not only housekeeper cells responsible for maintenance and repair — but are the primary source of brain cholesterol which makes communications between your brain cells possible. But every day 38.6 million Americans take a drug that robs their brain of this essential nutrient. Are you one of them? Click here to find out!
- Glymphatic System May Play Key Role in Removing Brain Waste — Neurology Reviews
- How to optimise your brain’s waste disposal system — The Guardian
- Roots of Alzheimer’s and Parkinson’s May Be in How You Sleep — Brain Blogger
- Ten Good Reasons Why You Should Get A Good Night’s Sleep — Brain Blogger
- Brain-wide pathway for waste clearance captured by contrast-enhanced MRI — The Journal of Clinical Investigation
- Brain may flush out toxins during sleep — National Institutes of Health
- Brain Drain — Scientific American
- When scientists saw the mouse heads glowing, they knew the discovery was big — Washington Post
- Brains flush toxic waste in sleep, including Alzheimer’s-linked protein, study of mice finds — Washington Post
- Goodnight. Sleep Clean. — The New York Times
- Brains Sweep Themselves Clean Of Toxins During Sleep — NPR
- How do waste chemicals accumulate in the brain? — Dr. Siddharth Kharkar
- The surprising danger seniors face from sleep loss — Easy Health Options