Your brain’s thirst for energy is just about insatiable. Because its neuronal networks constantly reshape themselves and transmit signals, these cells need constant refueling. But all that activity also floods the brain tissue with a never-ending flow of oxidative free radicals and protein debris.

To keep functioning correctly, your brain needs to routinely clear out the metabolic waste products and other toxins that accumulate among its neurons.

Luckily the human body has been designed to provide just this type of cleanse – with sleep.

Research now demonstrates that helping the brain deep clean itself is one of sleep’s most important duties.

“Waste clearance could be important, in general, for maintaining brain health or for preventing neurogenerative disease,” says researcher Ravi Allada, who chairs the department of neurobiology at Northwestern University’s Weinberg College of Arts and Sciences. “Waste clearance may occur during wakefulness and sleep but is substantially enhanced during deep sleep.”

In other words, unless you get enough deep sleep every night, the brain can get clogged with clumps of toxic byproducts that can wreak havoc with your memory and intellectual abilities.

Recovery for Tired and Injured Brains

Dr. Allada and his colleagues have performed some of their latest sleep research on fruit flies. Apparently, these little critters have daily deep sleep that’s surprisingly similar to human slumber!

The investigation, he says, shows that sleep “facilitates waste clearance and aids in (brain) injury recovery.”1 I would imagine this is one reason that doctors regularly put severely injured people into a medically induced coma, to help their bodies heal more quickly.

Remarkably, other researchers have shown that just about every living thing needs sleep to clean and rejuvenate their bodies. Even simple organisms without brains – even those without eyes – catch some “shuteye” every single day.

For example, a Japanese study of hydras, tiny freshwater organisms that possess nerves but no brain – and not even a central nervous system – shows that they need to sleep. Unlike us, though, they need sleep every four hours around the clock.2

Other studies examined how even jellyfish have to sleep. Researchers at the California Institute of Technology have shown that jellyfish sleep every night and that if their sleep time is interrupted and shortened, they act groggy the next day.3

The Best Medicine for Anxiety

Along with flushing out toxins and supporting better memory and recall, getting enough sleep can help decrease feelings of loneliness and anxiety.

A study at the University of California, Berkeley, indicates that when you’re sleep-deprived you feel more isolated and less able to socially interact with other people. In addition, the researchers found that your social alienation from losing sleep makes you less attractive to other people – because, say the researchers, your bad mood is contagious. It makes those you encounter feel just as depressed, anxious and moody as you feel.4

“We humans are a social species. Yet sleep deprivation can turn us into social lepers,” says researcher Matthew Walker, a Berkeley professor of psychology and neuroscience.

“The less sleep you get, the less you want to socially interact,” Dr. Walker adds. “In turn, other people perceive you as more socially repulsive, further increasing the grave social-isolation impact of sleep loss. That vicious cycle may be a significant contributing factor to the public health crisis that is loneliness.”

Dr. Walker, like most sleep experts, believes that all of us should be getting seven to nine hours of sleep a night. And you should start tonight. “Just one night of good sleep makes you feel more outgoing and socially confident, and furthermore, will attract others to you,” he says.

Sounds good to me.


  1. https://advances.sciencemag.org/content/7/4/eabc2999/tab-article-info
  2. https://advances.sciencemag.org/content/6/41/eabb9415 
  3. https://www.sciencemag.org/news/2017/09/you-don-t-need-brain-sleep-just-ask-jellyfish 
  4. https://pubmed.ncbi.nlm.nih.gov/30108218/