The lunar cycle affects the night sky, the tides and even the fertility of certain marine species. And it turns out, we can add your shuteye to the list. According to a new study, humans sleep poorly on nights near a full moon. The work is published in the journal Current Biology. [Christian Cajochen et al., Evidence that the Lunar Cycle Influences Human Sleep] To test the moon's effect, 33 adult volunteers of both sexes and various ages spent several nights in a sleep lab. As they dozed, researchers monitored their brain activity, eye movements and hormone levels. On nights closer to a full moon, the subjects took an average of five minutes longer to fall asleep, and slept for 20 minutes less. In addition, brain activity decreased by 30 percent during the sleep stage that the brain normally uses to recover from its daylight work. And levels of melatonin, the hormone that helps regulate sleep cycles, dropped. On these nights, the sleepers complained of poor sleep quality even though they were unaware of the lunar cycle. On the bright side, not a single participant turned into a werewolf. In this cohort. —Sophie Bushwick [The above text is a transcript of this podcast.] Follow Scientific American on Twitter @SciAm and @SciamBlogs. Visit ScientificAmerican.com for the latest in science, health and technology news.
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