The moon influences everything from tides to corals, but does it affect our sleep?
Studying moon cycles and sleep
In the 1970s, 1980s, and 1990s, researchers conducted studies to try to determine if women’s menstrual cycles were affected by the moon. Although the studies may have been too small to confirm anything, some of the studies did find changes in melatonin levels, menstrual cycles, and moon phases. Because melatonin regulates our sleep-wake cycle, these studies helped add to the theory that the moon affects our sleep.
More recent studies seem to point to the idea that the moon affects our quality of sleep.
In 2014, a study of 319 people found that during a full moon, participants remained awake or in a state of light sleep the majority of the time they were in bed. The research on this low sleep efficiency was published in the journal Sleep Medicine.
Before you assume it may just be the bright light of the full moon keeping you awake, consider this: A 2013 analysis of data on a previous sleep study found that exposure to bright moonlight couldn’t be a factor in many of the studies because the participants slept in a windowless, dark controlled environment.
For the study, 33 volunteers slept in windowless rooms for 3.5 days. The scientists measured:
- brain activity during sleep
- melatonin levels
- changes in sleep structure
- cortisol levels
The results
The researchers found that immediately before and after a full moon:
- sleep duration fell by 20 minutes.
- participants took about 5 minutes longer, on average, to fall asleep.
- melatonin levels dropped.
- sleep was lighter than usual.
“The lunar cycle seems to influence human sleep,” explains lead researcher Christian Cajochen of the University of Basel in Switzerland, “even when one does not ‘see’ the moon and is not aware of the actual moon phase.”
