Earlier this month when I reported on a new Gallup survey showing more than half of Americans don't get enough sleep, I went looking for research on just what this epidemic of sleep deprivation might be doing to us.
As you might expect, I uncovered plenty of studies showing insufficient sleep makes you grouchy, rude, a worse leader, and bad at your job. No shock there. Anyone who's ever tried to do anything demanding on too little sleep can tell you that. But I also found one study suggesting our bodies use sleep to flush out toxic proteins that build up in our brain.
Which sounds like a pretty compelling reason to get more sleep. Still, it's only one study. No need to panic yet, right?
Except, apparently, yet another lab has come to the exact same conclusion. Published in the prestigious journal Nature, this new paper comes to the same conclusion as previous research. Our bodies need adequate sleep to clear the trash out of our brains, and not getting enough could be seriously worrisome for your long-term brain health.
Sleep is your brain's dishwasher.
I stumbled across this latest study, conducted by a team out of the Washington University School of Medicine in St. Louis, via the newsletter of Emily Oster. A Brown University economist, Oster has made a career of translating complex scientific findings into plain English and actionable insights for everyday families (her book Expecting Better saved my sanity when I was pregnant). So I am fairly confident she offers a balanced, fair-minded summary of the findings for the non-expert reader.
Here's what how she sums them up:
To vastly oversimplify: What the authors are able to show here is, first, that during sleep the pattern of brain activity works together in a way to generate strong waves that could effectively move out metabolic waste. Second, they show that when they intervene with the mice to flatten the sleep brain waves, the cerebrospinal fluid is less able to get around the brain.
Li-Feng Jiang-Xie, the first author of the study, put it even more simply when explaining the team's research: "We think the brain-cleaning process is similar to washing dishes." A particular pattern of brain waves, available to us only when we sleep, is the brain's sponge, scrubbing out the gross gunk that builds up when we're awake.
What exactly is this grime our brains are trying to clean out? Bits of broken-down protein and other waste products that have been linked to diseases such as Alzheimer's and Parkinson's, "in which excess waste ... accumulates in the brain and lead to neurodegeneration," Jiang-Xie explains.
More science is needed.
It's worth underlining that this is frontier science, and more investigation is needed. There have even been some studies with mice that suggest that sleep might not be as effective at cleaning out the brain's trash as other studies indicate.
That's how science advances, through experimentation and debate. But in the meantime, as Oster puts it, "this is an incredibly cool paper," and it's pointing in a direction we should all probably go anyway.
No matter what future research shows, sleep is clearly hugely important for the healthy and effective functioning of your brain. It looks like it probably also keeps it free of toxic gunk and on the road to healthy brain aging too. If that's not a good enough reason to prioritize sleep, then I don't know what is.
