We’ve all been hearing how important it is to get a good night’s sleep. Insomnia has recently been linked to all sorts of health problems, including diabetes, weight gain, high blood pressure, heart disease, and even a shortened lifespan.
Still, Americans are struggling. The Centers for Disease Control and Prevention (CDC) estimates that 50-70 million adults have trouble sleeping. In addition to health problems like sleep apnea, snoring, and restless leg syndrome, we also have modern factors such as longer work schedules, constant access to technological gadgets, and inconsistent bedtime routines.
Now, a new study suggests that something else may be disturbing our sleep—something that many people have suspected for years, but that science has failed to confirm until recently. Though long blamed for occasional madness and the emergence of werewolves, the full moon is now suspected of actually affecting sleep in humans.
Could lunar rhythms be keeping you from getting the sleep you need?
What the Study Found
Sleep researcher Christian Cajochen at the Psychiatric Hospital of the University of Basel in Switzerland was reportedly skeptical when people complained about being unable to sleep as well during the full moon. Yet previous studies had indicated that the moon could affect people in a variety of ways, so he decided to look into the subject further.
“If you ask people,” Cajochen said, “at least in Switzerland, about 40 percent report feeling the moon during sleep, or they blame the full moon for bad sleep.”
To get to the truth of the matter, Cajochen and colleagues monitored 33 volunteers—between the ages of 20 and 74—in a sleep lab for 3.5 days, at various times during the lunar cycle. The lab had no windows, so the participants could not see the moon. They also did not know that the phase of the moon would become part of the study.
Scientists looked at brain activity, eye movements, and hormone secretions while the participants slept, recording the data. None of the participants took medication, and all were healthy and good sleepers.
Results showed the following. During the full moon:
- Brain activity related to deep sleep dropped by 30 percent.
- People took five minutes on average to fall asleep.
- People slept for 20 minutes less overall on full-moon nights.
- Participants felt their sleep was poorer when the moon was full.
- Scientists found that melatonin levels—a hormone known to regulate sleep cycles—was lower during the full moon.
“We have evidence that the distance to the nearest full-moon phase significantly influences human sleep and evening melatonin levels when measured under strictly controlled laboratory conditions, where factors such as light and personal moon perception can be excluded,” the researchers wrote.
Hesitant to Publish
Interestingly, the scientists were hesitant to publish the results, because they were so skeptical that the moon could really affect sleep. In fact, the data came from an experiment done 10 years ago—Cajochen and colleagues waited until now to analyze and publish the results.
“I was really skeptical about the finding,” Cajochen said, “and I would love to see a replication.”
There are some reasons to question the results. The study was small, with only 33 participants, and the researchers didn’t control what the volunteers were exposed to the week before the study, which also could have affected the quality of their sleep. Conducting the study over a longer period of time—at least 30 days, to cover the entire lunar cycle—would produce more reliable results.
Why Would the Moon Affect Sleep?
Researchers speculated that the human brain may have an internal clock that is somehow synchronized with the moon. We already accept that we are affected by circadian rhythms—the 24-hour cycle coordinated with day and night—so it isn’t that far of a jump to think we may also be affected by lunar cycles.
Some other studies have hinted that the moon may affect sleep. A 2006 study, for instance, found that participants sleep duration varied with the lunar cycle, from 6 hours and 41 minutes during a full moon, to 7 hours during the new moon. They also found that participants rated themselves as being more tired after a full moon.
Other studies, however, have found no effect on humans from the full moon, so this study is unique in presenting solid evidence to the contrary.
Until we have more studies, we can’t be positive of the effects, but in the meantime, how can you adapt? Researchers say that you can’t easily change the body’s response in this case. The participants in the study slept with no windows, so it wasn’t the brightness that affected them. Your best bet is to adopt a regular bedtime routine that you stick with, which will help you sleep well regardless of what’s going on with the moon.
Do you find your sleep upset by the full moon? Please share your story.
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Charles Choi, “Bad Sleep? Blame the Moon,” LiveScience, July 25, 2013, http://www.livescience.com/38435-full-moon-affects-sleep.html.
Elizabeth Landau, “Full moon may disrupt sleep, study says,” CNN, July 26, 2013, http://thechart.blogs.cnn.com/2013/07/26/full-moon-may-disrupt-sleep-study-says/?hpt=he_bn7.
Roosli M., et al., “Sleepless night, the moon is bright: longitudinal study of lunar phase and sleep,” J Sleep Res. 2006 Jun; 15(2):149-53, http://www.ncbi.nlm.nih.gov/pubmed/16704569.