Could the Moon Affect Our Sleep?

Sleep experts say that in these modern times, it’s challenging to determine natural human sleep patterns. We wake up to an alarm rather than with the rising sun. We extend our daytime into the night with artificial light, and these days we might even beam that light right into our eyes with smartphones and tablets at bedtime, which can really mess up our natural sleep cycle.

So, to learn about inborn human sleep patterns, experts often observe the sleep habits of rural people who live without electricity. For example, to determine whether the phases of the moon influence human sleep patterns, University of Washington (UW) sleep experts recently compared the sleep patterns of students at their Seattle campus—certainly a plugged-in bunch—with the slumber habits of members of the Toba-Qom indigenous communities of northern Argentina, who for the most part have little access to electricity.

The UW scientists found that in the three to five days leading up to a full moon, people with little access to electricity go to sleep later and get fewer minutes of sleep. This seems logical—the moonlight would provide more hours in which to get things done. But the team also found that the urban college students’ sleep patterns were similar. Why would that be?

UW biology researcher Leandro Casiraghi suspects that our natural 24-hour cycle of sleep and wakefulness is tied to lunar phases. “In general, there has been a lot of suspicion that the phases of the moon could affect a behavior such as sleep—even though in urban settings with high amounts of light pollution, you may not know what the moon phase is unless you go outside or look out the window,” said Casiraghi. “At certain times of the month, the moon is a significant source of light in the evenings, and that would have been clearly evident to our ancestors thousands of years ago.”

Sleep experts say taking advantage of our natural sleep-wake rhythms can help us improve our sleep. Leading sleep expert Michael Vitiello, also of the University of Washington, has conducted research on sleep among older adults. He warns that pain and disability can make it hard for older adults to sleep well—and poor-quality sleep, in turn, increases pain and disability. He recently offered suggestions for better slumber:

Prioritize sleep. Just as we should make time for eating well and exercising, we need to get sleep on our schedule—and it’s not possible to truly “catch up” on lost sleep. “Sleep is not like a bank account,” says Vitiello. “There is always a biological cost for not getting enough sleep. It might be small, but it adds up over time.”

Go to bed and get up at the same time each day. Vitiello says that some people do all right with variable schedules, but those who are having trouble sleeping could benefit from maintaining a regular sleep schedule seven days a week.

Match your time in bed to your sleep need. Lying in bed awake can cause anxiety, and that can make it all the harder to sleep. “Do not spend a lot of time in bed while not asleep,” advises Vitiello. “If you are staying in bed longer because you think you will get more sleep, you will not. Get up if you cannot sleep and try again after a short period of time.”

Give your sleep space a makeover. Darken the room with window coverings if necessary, cut down on noise, and adjust bedding for a comfortable sleep temperature. Vitiello also reminds us not to use our bed for paying bills or other activities that promote alertness.

Have a sleep-friendly daytime routine, as well. Get enough exercise, spend time in natural light, and limit alcohol. “Alcohol does not facilitate sleep,” says Vitiello. “It makes you dehydrated and could lead to fragmented sleep.”

Consider your napping. Vitiello says 20- to 30-minute naps can be beneficial for people who need a little extra shuteye—but sleeping too much during the day can make it harder to sleep at night.

If sleep problems persist, consult an expert. “If these tips do not improve your sleep, then consider discussing it with your primary care provider or consult a sleep center,” says Vitiello. “Recognize that sleep centers specialize in treating sleep disorders and are likely better able to address your concern than your primary care physician.”