donation
To request Mental Health
Services or to access Mental
Health Crisis Services Call:
1-800-375-4357

Wellness and Personal Development
Resources
Basic InformationLatest News
Alcohol Is No Friend to Social DistancingFeeling Down? Support Via Social Media May Not Be Enough'BPA-Free' Bottles Might Need a Run Through Your Dishwasher FirstAHA News: 5 Critical Steps to Help Prevent a StrokeWhat's the Right Amount of Sleep for a Healthy Heart?AHA News: Take Stock of Your Health With This Post-Lockdown ChecklistYou & Your Friends Are Vaccinated. So Why Is Socializing Again Scary?Even Before COVID, Many More People Died Early in U.S. Versus EuropeYour Zip Code Could Help or Harm Your BrainAHA News: 5 Things to Know This Earth Day About How the Environment Affects HealthPhysically Active at Work? It's Not as Healthy as Leisure ExerciseRe-focusing on Getting Fit? Heart Experts Offer These TipsNearly Half of U.S. Veterans Cited 'Personal Growth' During Pandemic: SurveyAHA News: The Secret to Good Health Is No Secret. So Why Is It So Hard to Achieve?'Couch Potato' Lifestyles Cause Up to 8% of Global Deaths: StudyHave to Travel During Spring Break? Here's How to Stay SafeGen X, Millennials in Worse Health Than Prior Generations at Same Age'Game of Thrones' Study Reveals the Power of Fiction on the MindTry 'Microbreaks' for a Real Workday BoostCan Fitbits, Apple Watch Be a Dieter's Best Friend?Spring Cleaning Can Sweep Away Allergens From Your HomeUnhealthy in Your 20s? Your Mind May Pay the Price Decades LaterAHA News: How to Get Better Sleep Amid the Pandemic – And Why You ShouldDoubly Good: Healthy Living Cuts Your Odds for the 2 Leading KillersDrink Up! Humans Are the 'Water-Saving Apes''Spring Forward' This Weekend By Checking Your Home Smoke AlarmsClocks 'Spring Forward' on Sunday: Be PreparedWhich Americans Live Longest? Education Matters More Now Than RaceThe Skinny on Wrinkle-Free SkinSnow Shoveling, Slips on Ice Bring Cold Weather DangersWhen Facebook, Twitter Flag Posts as 'Unverified,' Readers ListenAHA News: Calming Us Down or Revving Us Up, Music Can Be Good for the HeartGet Your '5 a Day' Fruits and Veggies to Live LongerAHA News: Why Experts Say a Good Mood Can Lead to Good HealthGrumpy? Depressed? Try a More Regular Sleep ScheduleCold Facts on Avoiding Snow and Ice DangersDrivers May Be Inhaling Dangerous Carcinogens Inside Their CarsAHA News: Watch Your Heart Rate, But Don't Obsess About ItMany U.S. Adults Aren't Getting Healthy Amounts of Fruits, VegetablesPoll Finds Americans Highly Stressed by Politics, PandemicCould Working Outside Help Prevent Breast Cancer?Kiss Chapped Lips Goodbye This WinterAHA News: 5 Things Nutrition Experts Want You to Know About New Federal Dietary GuidelinesLockdowns Might Not Have Long-Term Psychological Effect: StudyAre the Moon's Phases Affecting Your Sleep?AHA News: The Head Is Connected to the Heart – and Can Influence HealthMaybe Money Can Help Buy Happiness, After AllStressed Out By the News? Here's Tips to Help CopeVision Problems? Here's a Guide to Which Specialist Is Right for YouFacebook Posts Big Drivers in Vaccine Resistance, Study Finds
LinksBook Reviews
Related Topics

Smoking
Anger Management
Stress Reduction and Management
Weight Loss

Too Much or Too Little Sleep Bad for Your Brain

HealthDay News
by By Steven Reinberg
HealthDay Reporter
Updated: Sep 21st 2020

new article illustration

MONDAY, Sept. 21, 2020 (HealthDay News) -- Everyone needs sleep, but too little or too much of it might contribute to declines in thinking, a new study suggests.

Too little sleep was defined as four or fewer hours a night, while too much was deemed 10 or more hours a night. The ideal amount? Seven hours a night.

"Cognitive function should be monitored in individuals with insufficient or excessive sleep," said study author Yanjun Ma, from Peking University Clinical Research Institute, in China.

Still, Ma cautioned that the study can't prove that too little or too much sleep causes mental ("cognitive") decline, only that there appears to be an association.

According to the National Sleep Foundation, sleep is essential because it lets your body and mind recharge. The right amount of sleep also helps you stay healthy and prevent diseases.

Without enough sleep, the brain cannot function properly, impairing concentration, clear thinking and memory-processing.

But the mechanisms underlying these associations remain unclear. It's possible that inflammation might be related to excessive sleep, Ma said.

Meanwhile, too little sleep might increase cerebrospinal fluid levels of amyloid plaque and tau protein, which are hallmarks of Alzheimer's disease, Ma added.

Dr. Sam Gandy, associate director of the Mount Sinai Alzheimer's Disease Research Center in New York City, added, "More than any other time in the circadian cycle, during sleep, the brain's glymphatic system is active in washing out excess levels of toxins, including amyloid-beta peptide."

Each person probably has some optimum balance between sleep and amyloid clearance, with too much or too little of one causing the other to tip in the wrong direction, he explained.

"The technology for individual optimization has not been generally rolled out to the level of toxins in the brain, but this looks to be an important emerging area," Gandy said. "Optimizing sleep and amyloid clearance is likely to join sleep apnea as another readily treatable factor driving late-life cognitive decline."

For the study, Ma's team collected data on more than 20,000 men and women who took part in either the English Longitudinal Study of Aging or the China Health and Retirement Longitudinal Study.

Participants reported their sleep habits and were given tests of cognition.

During follow-up, cognitive scores dropped faster among people with four hours or fewer and 10 hours or more of sleep per night than those who slept seven hours per night, the researchers found.

This association is called a U-shaped relationship, because the effects of sleep on cognition are seen at both ends of the curve.

The report was published online Sept. 21 in JAMA Network Open.

Dr. Yue Leng, an assistant professor of psychiatry at the University of California, San Francisco, co-authored an editorial that accompanied the study. She said, "An increasing number of studies have found a U-shaped relationship between sleep duration and cognition, where both short and long sleep duration was associated with worse cognition."

But the implication of this U-shaped relationship is unclear, partly because of the limitations in study design, Leng said.

To really determine how sleep affects cognition, studies need to go beyond sleep duration and take into account both sleep quality and quantity, Leng noted. Perhaps, then, sleep can be used in the prevention and management of dementia, she suggested.

"It has been almost two decades since sleep duration was first suggested to be linked with cognitive health in older adults," Leng said. "Better study design and more valid and reliable measurements are needed to help clarify this relationship."

The National Sleep Foundation recommends that adults get seven to nine hours of sleep each night.

To get a good night's sleep, the foundation recommends having good sleep habits that include:

  • Having a realistic bedtime and sticking to it every week and weekend night.
  • Keeping the bedroom cool and dark.
  • Banning televisions, computers and tablets, cellphones and other electronic devices from the bedroom.
  • Not ingesting caffeine, alcohol or large meals in the hours before bedtime.
  • Not using tobacco day or night.
  • Exercising during the day, which can help you wind down and get ready for sleep.

More information

For more on sleep, head to the Sleep Foundation.