Benefits of Sleep for Flu Prevention

With flu season on its way, now is the time to take steps to avoid that pesky virus. Flu seasons run roughly from early October through April, sometimes even into May, but the severity varies from year to year. It’s impossible to accurately predict what to expect this season, according to the Centers for Disease Control and Prevention. But some things never change, such as what you can do to reduce your risk of catching the flu.

Children and the elderly have the greatest risk of complications from the flu, but anyone can catch it and possibly end up in the hospital, or worse, according to the CDC. If you are exposed, what matters most is that your body has the resources to fight back. That starts with getting vaccinated, according to Dr. Jay Kahng, an internist at Providence Saint John’s Health Center in Santa Monica, California. The flu vaccine’s effectiveness fluctuates, but any protection is better than none.

Common-sense hygiene rules also apply, such as regularly washing your hands and covering your mouth when you cough. But just as important is getting a good night’s sleep every night. The National Heart, Lung, and Blood Institute recommends adults sleep seven to eight hours a night. Children need at least 10 hours each night, and teenagers need nine to 10 hours a night.

“If we do not sleep well, our body does not get a chance to develop and maintain the healthy immune system,” Kahng says. “Without it, we are more susceptible to viral infections such as the flu.”

In fact, research has shown that being well rested is important even when you get the vaccine, says the Sleep Geek, Sleep Number’s Vice President of Sleep Science & Research Pete Bils.

“Chronic lack of sleep is not only associated with an increase in inflammation but also causes immunodeficiency,” says Dr. Arfa Babaknia, a group medical director at the Memorial Medical Group in Fountain Valley, California. “People who receive the flu vaccine will decrease their immunity against the flu after just one week of insomnia.”

A study in the Nature journal Scientific Reports found evidence for the strong link between sleep and immune system functioning when researchers tracked nearly 3,000 adults for several years. They discovered that those with more daytime sleepiness also developed more infections over that time.

More recently, researchers reported this June in the journal JAMA Internal Medicine that adults who got five hours of sleep or less each night had nearly twice the risk of developing infections such as influenza or pneumonia compared to those who slept seven to eight hours a night.

“We know from laboratory studies that sleep is intimately related to the immune system,” says Aric Prather, an assistant professor of psychiatry and neuroscience at the University of California, San Francisco, and the lead author of that study. “When sleep is deprived, for a night or even just part of a night, many aspects of the immune system key to protecting us from viruses are affected.”

Even when Prather’s team took into account factors such as smoking, physical activity and weight, short sleepers had 50 percent greater odds of getting an infection than those getting seven to eight hours per night. These findings matched up with a 2015 study that Prather conducted and reported in the journal Sleep that found individuals were four times more likely to catch the common cold when they slept just five to six hours or less per night compared to those who got at least seven hours of shut-eye.

Some people dismiss the flu as just a few days of feeling cruddy, but influenza can knock you flat with fever, aches and pains for two weeks. It sends thousands of people to the hospital every year. That makes sleep even more important if you do come down with the flu.

“Sleep appears to play an important role in recovery, though how this exactly happens is not well known,” Prather says. “It’s possible that energy needed to power the immune system, particularly during an infection, may be more easily diverted during sleep than during wake time.”

But one thing is clear: if you want to stay healthy this winter, whether it’s avoiding a common cold or more serious infections like flu, you need your sleep.

As Prather notes, “the scientific literature supporting a link between sufficient sleep and physical health gets stronger every day.”