The Healing Power of Sleep [WebMD]

Reviewed by William Blahd, MD on October 06, 2016

When you nod off, it seems like your body powers down for the night. But as you sleep, your body actually repairs and restores itself.

“Think of sleep as the tuneup you need to run smoothly,” says David M. Rapoport, MD. Rapoport is director of the Sleep Medicine Program at NYU Langone Medical Center.

You should aim to get 7 to 8 hours of shut-eye every night. That gives your body the time it needs for sleep to take care of you, including these seven important things.

1. Saves You Hundreds of Calories

To protect your waistline, make bedtime a priority. A study in the American Journal of Clinical Nutrition showed that people ate an average of nearly 300 fewer calories per day when they were well-rested.

A solid night of sleep may provide extra willpower to resist those cookies or chips. “We’re discovering that a part of the brain that controls sleep also plays a role in appetite and metabolism,” Rapoport says.

When you skimp on your ZZZs, your body makes more ghrelin and less leptin. Ghrelin is a hunger hormone, and leptin is a hormone that tells you when you’re full.

2. Makes You Smarter

You absorb thousands of things every day, like new words or a new routine in your Zumba class. When you sleep, your brain sorts through all of this info.

“It decides what to store and what to toss,” Rapoport says. The important details become memories you can call upon later.

“If you’re trying to learn something, go to bed,” Rapoport says. Chances are you’ll remember that speech or perform those dance moves better in the morning.

3. Brightens Your Mood

When you toss and turn all night, chances are good you'll be cranky the next day. But when you’re refreshed, it’s so much easier to be pleasant.

“Sleep allows your mind and body to rest,” Rapoport says. “This can give you energy and a more positive outlook.” It can also help you manage stress.

Over the long run, these benefits may protect your mental health. Research in the journal SLEEP showed that people who snoozed 7 to 9 hours a night had fewer symptoms of depression than those who slept more or less.

4. Heals You From the Inside Out

While you sleep, your brain triggers the release of hormones that encourage tissue growth. This can help you recover from injuries such as cuts or even sore muscles from your last workout.

Quality ZZZs also help your body defend itself. During sleep, you make more white blood cells that attack viruses and bacteria, says Sunita Kumar, MD. Kumar co-directs the Center for Sleep Disorders at Loyola University Medical Center.

In one study, people who slept at least 8 hours a night were 3 times less likely to come down with a cold than those who got 7 hours or less.

5. Guards Your Heart

Your blood pressure dips as you snooze. That may give your heart a break. There may be other heart health benefits, too.

For instance, your body tweaks your stress hormones during sleep, Kumar says. This, in turn, may curb inflammation, which is linked to heart disease, diabetes, and many other conditions. 

6. Revs You Up

Get enough sleep, and you’ll have enough energy to do all kinds of things. A study in the Journal of Sexual Medicine found that women who slept better also had more sexual desire.

7. Makes Tough Decisions Easier

Stumped about something? Hit the hay, and you may wake up to a new way of looking at it. It’s true: You should sleep on big issues.

You need to get enough sleep to think well. “It’s the difference between firing on four and six cylinders,” Rapoport says.

It can also boost your creativity. Your rested brain is better prepared to tap into your unconscious thoughts. And that helps you find the best solution.

WebMD Feature

SOURCES:

David M. Rapoport, MD, director, Sleep Medicine Program, NYU Langone Medical Center; professor of medicine, NYU School of Medicine.

Sunita Kumar, MD, co-director, Center for Sleep Disorders, Loyola University Medical Center; associate professor of medicine, Loyola University.

Watson, F. SLEEP, Feb. 1, 2014.

Cohen, S. Archives of Internal Medicine, Jan. 12, 2009.

Taheri, S. PLoS Medicine, Dec. 7, 2004.

Kalmbach, D. Journal of Sexual Medicine, May 2015.

Nordgren, L. Journal of Experimental and Social Psychology, March 2011.

St. Onge, M. American Journal of Clinical Nutrition, August 2011.