Everything you need to know about sleep, but are too tired to ask

October 18, 2017 by Yasmin Anwar, University of California - Berkeley
UC Berkeley neuroscientist Matthew Walker and his new book, Why We Sleep. Credit: Matthew Walker

Ask neuroscientist Matthew Walker, author of the new book, Why We Sleep, about the downside of pulling an all-nighter, and he'll rattle off a list of ill effects that range from memory loss and a compromised immune system to junk food cravings and wild mood swings.

There was that time, for instance, when two straitlaced football players stayed up all night in his campus lab for a memory experiment. By morning, the two were grinning maniacally with lipstick and mascara smeared across their faces. Their makeup had been slapped on by two similarly -deprived female students.

"It was a striking demonstration of the emotional and personality impact of insufficient sleep," marvels Walker, a UC Berkeley professor of neuroscience and psychology and leading sleep evangelist.

Walker, 43, a native of Liverpool, U.K., is dead serious about the dangers of sleep deprivation—now more than ever, perhaps, as bedrooms everywhere glow from the screens of round-the-clock technology consumption.

"The silent sleep loss epidemic is one of the greatest public health challenges we face in the 21st century," says Walker, who has served as a sleep consultant to the NBA, NFL and Pixar Animation Studios, among other Fortune 500 enterprises.

A sleep evangelist

In Why We Sleep: Unlocking the Power of Sleep and Dreams, published by Scribner and released earlier this month, Walker guides readers through decades of . He describes how the overtired brain and body make us vulnerable to cancer, Alzheimer's, depression, anxiety, obesity, stroke, chronic pain, diabetes and heart attacks, among other medical conditions.

The book also explains the power of circadian rhythms, the therapeutic importance of Rapid Eye Movement (REM) dream sleep, and how alcohol, caffeine, pharmaceutical stimulants and sedatives disrupt sleep cycles and degrade the quality of brain waves that promote the rich slumber that wards off illness.

Cumulatively, he argues, the cognitive, emotional and physiological stresses of too few hours of sleep take a toll on such frontline personnel as military fighters, first responders, commercial airline pilots and long-haul truck drivers, leading to vehicular accidents, botched surgeries and fatalities, and, in the case of exhausted parents, child neglect and abuse.

" 'I just snapped and '… those words are often part of an unfolding tragedy as a soldier irrationally responds to a provocative civilian, a physician to an entitled patient or a parent to a misbehaving child," Walker writes. "All of these situations are ones in which inappropriate anger and hostility are dealt out by tired, sleep-deprived individuals."

Using functional Magnetic Resonance Imaging (fMRI) to measure neural blood-flow activity, as well as electroencephalogram (EEG) tests to monitor neural electrical activity, Walker and his research team have peered into the brains of adults of all ages to test memory and learning, decision-making, emotional processing and reactivity, stress and evidence of proteins believed to trigger Alzheimer's disease.

Their discoveries have been published in numerous peer-reviewed journals, and made headlines, contributing to a growing body of scientific evidence showing that a solid seven to nine hours of sleep a night serves functions beyond our wildest imaginations.

Animals more sleep-smart than humans

Of all the creatures in the animal kingdom, the book argues, humans are the only ones to "deliberately deprive themselves of sleep for no sound reason," Walker says.

Lions and tigers typically snooze 15 hours a day while brown bats sleep for a whole 19 hours. Dolphins, Walker says, "can even sleep with half a brain," meaning that one hemisphere of the brain remains awake at all times while the other falls, off and on, into a deep slumber.

If, as research shows, sleep functions like a fountain of youth, why aren't humans getting more of it? Walker asks.

"There does not seem to be one major organ within the body, or process within the brain, that isn't optimally enhanced by sleep (and detrimentally impaired when we don't get enough). That we receive such a bounty of health benefits each night should not be surprising," Walker writes.

A whiz kid of sorts, Walker entered Queen's Medical School in the U.K. at 18, but quickly discovered that brain science appealed to him more than the prospect of becoming a medical doctor. As a Ph.D. student in neurophysiology, he noted an unusual pattern of brain waves during sleep in older patients with dementia.

"I wanted to know if sleep carried within it a distress call, a warning beacon that spoke out which type of dementia a patient was in the early stages of," he says. "If I could find that disease clue in the electrical brainwaves of sleep, I could begin diagnosing these patients years or even decades in advance."

A sequel in the works

That mission took him to Harvard Medical School as professor of psychiatry, and then, in 2007, to UC Berkeley, where he continues his work today as a professor of neuroscience and psychology and serves as director of the Center for Human Sleep Science.

Keenly aware of how sleep consolidates fact-based learning and memories, Walker is flattered when students snooze during his lectures.

As for his own sleep profile, Walker is dedicated to getting his nightly eight hours despite a busy work and public speaking schedule that involves occasional travel and jetlag.

Meanwhile, he has no plans whatsoever to veer from his mission to make more discoveries about the panacea that is sleep, including a sequel to Why We Sleep.

"I am in love with finding any and all methods for reuniting humanity with the sleep it so desperately needs," Walker says. "Ever and always I will be a sleep researcher."

Walker's tips for improving your sleep

  • Go to bed and wake up at the same time every day, even after a bad night's sleep or on the weekend.
  • Keep your bedroom temperature cool; about 65 degrees Fahrenheit is optimal for cooling your body towards sleep. Wear socks if your feet are cold.
  • An hour before bedtime, dim the lights and turn off all screens. Blackout curtains are helpful.
  • If you can't sleep, get out of bed and do something quiet and relaxing until the urge to sleep returns. Then go back to bed.
  • Avoid caffeine after 1 p.m. and never go to bed tipsy. Alcohol is a sedative and sedation is not sleep. It also blocks your REM dream sleep, an important part of the .

Explore further: Sleep and Alzheimer's disease connection

Related Stories

Sleep and Alzheimer's disease connection

October 17, 2017
How often do you get a good night's sleep? Centers for Disease Control and Prevention guidelines recommend adults get an average of at least seven hours of sleep a night. Dr. Ronald Petersen, a Mayo Clinic neurologist, says ...

An epidemic of dream deprivation: Review finds unrecognized health hazard of sleep loss

September 29, 2017
A silent epidemic of dream loss is at the root of many of the health concerns attributed to sleep loss, according to Rubin Naiman, PhD, a sleep and dream specialist at the University of Arizona Center for Integrative Medicine, ...

Sleep duration may affect the integrity of sperm DNA

October 16, 2017
A new study found a link between sleep duration and a measure of chromosomal health in sperm. The findings are published in the Journal of Sleep Research.

How much sleep do you really need?

July 20, 2017
(HealthDay)—Health initiatives typically center on diet and fitness. But the American Academy of Sleep Medicine and the Sleep Research Society state that getting enough sleep is just as important as eating right and exercising.

The sleep-deprived brain can mistake friends for foes

July 15, 2015
If you can't tell a smile from a scowl, you're probably not getting enough sleep.

No rest for the aged: As people get older, sleep quantity and quality decline

April 5, 2017
As people get older, they sleep less and wake up more frequently. Despite the thousands of sitcom jokes about it, these shifts in sleeping habits have a dark side. A recent review of scientific literature published in Neuron ...

Recommended for you

Juul e-cigarettes pose addiction risk for young users, study finds

October 19, 2018
Teens and young adults who use Juul brand e-cigarettes are failing to recognize the product's addictive potential, despite using it more often than their peers who smoke conventional cigarettes, according to a new study by ...

Adding refined fiber to processed food could have negative health effects

October 19, 2018
Adding highly refined fiber to processed foods could have negative effects on human health, such as promoting liver cancer, according to a new study by researchers at Georgia State University and the University of Toledo.

Self-lubricating latex could boost condom use: study

October 17, 2018
A perpetually unctuous, self-lubricating latex developed by a team of scientists in Boston could boost the use of condoms, they reported Wednesday in the journal Royal Society Open Science.

How healthy will we be in 2040?

October 17, 2018
A new scientific study of forecasts and alternative scenarios for life expectancy and major causes of death in 2040 shows all countries are likely to experience at least a slight increase in lifespans. In contrast, one scenario ...

Study finds evidence of intergenerational transmission of trauma among ex-POWs from the Civil War

October 16, 2018
A trio of researchers affiliated with the National Bureau of Economic Research has found evidence that suggests men who were traumatized while POWs during the U.S. Civil War transmitted that trauma to their offspring—many ...

Father's nicotine use can cause cognitive problems in children and grandchildren

October 16, 2018
A father's exposure to nicotine may cause cognitive deficits in his children and even grandchildren, according to a study in mice publishing on October 16 in the open-access journal PLOS Biology by Pradeep Bhide of Florida ...


Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.