7 common sleep myths that could be affecting your health

While hitting the snooze button in the morning or having a nightcap before bed may seem like ways to get more sleep, these myths may actually be harming your health, according to new research.

A good night's sleep is essential for overall health, yet sleep issues plague millions of Americans. A number of factors affect sleep, including genetics and various medical issues, but researchers from NYU School of Medicine were curious about the role common myths and misconceptions about sleep might play.

"Sleep is a vital part of life that affects our productivity, mood, and general health and well-being," the study's lead investigator, Rebecca Robbins, PhD, a postdoctoral research fellow at NYU Langone Health, said in a statement. "Dispelling myths about sleep promotes healthier sleep habits which, in turn, promote overall better health."

The researchers reviewed more than 8,000 websites to identify the 20 most common assumptions about sleep that were based on questionable scientific evidence. With a team of sleep medicine experts, they ranked them on both their degree of truth or falsehood, and on the harm that the myth could cause to health.

Here are some of the most significant sleep myths they found.

Myth 1: Many adults need only 5 or fewer hours of sleep

Researchers ranked this myth as "a great deal" false and as having "a great deal" of public health significance.

Adults aged 18 to 60 should sleep at least 7 hours per night for optimal health and wellness, according to sleep specialists and the U.S. Centers for Disease Control and Prevention. Only a very tiny percentage of the population truly functions as well on less sleep.

Long-term, getting insufficient sleep has been linked to a number of chronic diseases, including hypertension, diabetes, and obesity, as well as mood disorders like depression and anxiety. Lack of sleep can also affect productivity and concentration and lead to preventable accidents.

Myth 2: Snoring is mostly harmless

While snoring from time to time can be normal, chronic snoring can be a sign of sleep apnea, a potentially serious sleep disorder in which breathing repeatedly stops and starts. This can lead to daytime fatigue, and the repeated awakenings make regular, quality sleep impossible.

If left untreated, sleep apnea can also increase the risk of high blood pressure, heart problems, type 2 diabetes, abnormal cholesterol levels, liver problems, and complications with medications and surgery.

Therefore, loud or bothersome snoring may be an indication that you should consult with a doctor, the researchers say.

Myth 3: Alcohol before bed will help you sleep

While folklore suggests that a nightcap brings on sweet slumber, alcohol before bed can actually have a negative impact on sleep.

"The literature on sleep and alcohol shows alcohol consumed close to bedtime reduces sleep latency but subsequently causes sleep disturbances in the second half of the night," the researchers write. In other words, drinking alcohol may help you fall asleep quicker, but it delays the onset of deep REM sleep.

Alcohol consumption has also been shown to worsen the symptoms of sleep apnea.

Myth 4: It doesn't matter what time you sleep

While the researchers acknowledge that getting sleep during the day is better than no sleep at all, there's significant evidence that the timing of sleep is related to health.

Studies of night shift workers, whose circadian rhythms are disrupted, show they report less sleep and lower sleep quality than daytime workers. Night shift workers are also at a higher risk for long-term health issues like depression, diabetes, and cancer.

Myth 5: Your brain and body can learn to function just as well with less sleep

While many people may believe that they can learn to adapt to getting less sleep, the researchers found this to be false. Instead, studies show that even after weeks of tracking, reduced sleep leads to decreased daytime performance.

The researchers again point to night shift workers, who typically sleep less than those with daytime schedules and face a higher risk of death from any cause.

Myth 6: Hitting the snooze is better than getting up when the alarm first goes off

While there is little research looking at the effects of hitting the snooze button, disturbing sleep is "not optimal," the researchers say, and can have a negative impact on mood and cognition.

"Evidence suggests it may be best to set the alarm when one needs to get up instead of setting multiple alarms that might interrupt sleep," they write.

Myth 7: If you have difficulty falling asleep, it's best to stay in bed and keep trying

While it may seem counterintuitive, the sleep experts say this common practice is based on false assumptions. Instead, they recommend people having difficulty falling asleep should get out of bed and return only when they are tired.

However, if your goal is to get to sleep, it is important to avoid blue light from electronics, which disrupts circadian rhythms, so watching television and scrolling through social media are off limits. Try reading a book, listening to music or a podcast, or meditating.

Changing the perceptions of sleep myths

The researchers say their study sheds light on common misconceptions about sleep that, if cleared up, could improve overall health.

"Sleep is important to health, and there needs to be greater effort to inform the public regarding this important public health issue," said study senior investigator Girardin Jean Louis, PhD, a professor in the departments of Population Health and Psychiatry at NYU Langone. "For example, by discussing sleep habits with their patients, doctors can help prevent sleep myths from increasing risks for heart disease, obesity, and diabetes."

He notes the study also provides a framework for public health campaigns.

"Beliefs are associated with behaviors," the authors conclude. "Thus, altering health-related beliefs that are untrue is one promising strategy for promoting population health."