Five hours of sleep is not enough, even if you think it is.
Researchers at New York University School of Medicine scoured 8,000 websites to identify the most common assumptions about sleep, then ranked them based on whether it could be supported by research or dispelled as myth. Their findings were published in the online journal Sleep Health Tuesday.
Based on their findings, here are five beliefs about sleep the team found are nothing but myths.
Myth 1: You can get by on five hours of sleep
At the top of their list was the belief that people can function just fine by sleeping just five hours or fewer. "I function very well on 5 1/2 hours of sleep," Oprah Winfrey reportedly said in 2015. And German Chancellor Angela Merkel once said she could sleep four hours a night and then catch up on sleep on the weekend.
"We have extensive evidence to show sleeping five hours or less consistently increases your risk greatly for adverse health consequences," said lead investigator Rebecca Robbins, a postdoctoral research fellow in the Department of Population Health at NYU Langone Health.
A January study by National Center for Cardiovascular Research in Madrid determined that sleeping fewer than six hours a night can cause atherosclerosis — the hardening and narrowing of arteries — which is the usual cause of heart attacks and strokes.
Myth 2: Alcohol can help you sleep
Alcohol “may help you fall asleep, but it dramatically reduces the quality of your rest that night," Robbins said. Drinking alcohol before bed disrupts REM sleep, which occurs about 90 minutes after falling asleep.
“Alcohol may seem to be helping you to sleep, as it helps induce sleep, but overall it is more disruptive to sleep, particularly in the second half of the night,” researcher Irshaad Ebrahim said in 2013. “Alcohol also suppresses breathing and can precipitate sleep apnea,” or pauses in breathing that happen throughout the night.
Myth 3: Watching TV in bed helps you relax
"Often if we're watching the television it's the nightly news (or) it's something that's going to cause you insomnia or stress right before bed when we're trying to power down and relax," Robbins said.
The researchers also noted that televisions, like tablets and smart phones, produce blue light, which can delay the body’s production of melatonin.
Blue light can be dangerous in other ways. In July 2018, researchers at the University of Toledo in Ohio warned in the journal Scientific Reports that prolonged exposure to blue light — a high-intensity 445-nanometer shortwave emitted from digital screens, the sun and other electronic devices — can accelerate blindness and increase risk of eye disease.
Myth 4: It’s best to stay in bed and try to sleep
“Unfortunately, if we stay in bed we’ll start to associate our bed with insomnia,” Robbins said. She equates staying in bed when you can’t sleep with standing on a treadmill and doing nothing. Robbins recommends getting out of bed and doing something mindless, like folding socks.
Myth 5: It’s OK to hit the snooze button
No matter how tempting it is to get just a few more minutes, Robbins said it’s best to get up as soon as your alarm goes off and expose yourself to bright light.
"Realize you will be a bit groggy — all of us are — but resist the temptation to snooze,” she said. "Your body will go back to sleep, but it will be very light, low-quality sleep."
In addition to Robbins, study authors were Girardin Jean Louis, PhD, a professor in the departments of Population Health and Psychiatry at NYU Langone; Michael Grandner, University of Arizona College of Medicine; Orfeu M. Buxton, Pennsylvania State University; Lauren Hale, Stony Brook Medicine; Daniel J. Buysse and Sanjay R. Patel, University of Pittsburgh School of Medicine; Kristen Knutson, Northwestern University Feinberg School of Medicine; Wendy M. Troxel, RAND Coperation; Shawn Youngstedt, Arizona State University; and Charles Czeisler, Brigham and Women's Hospital and Harvard Medical School.