It’s not just the pandemic. The moon may be messing with your sleep, too.
Sleep and circadian rhythms have long been associated with the powerful effects of the sun cycle. But in recent years, a growing number of studies have suggested that another familiar celestial body might also be impacting your ability to get a restful night’s sleep: the moon.
A paper published this week in the journal Science Advances found that people tend to have a harder time sleeping in the days leading up to a full moon. Researchers reported that sleep patterns among the study’s 98 participants appeared to fluctuate over the course of the 29½ -day lunar cycle, with the latest bedtimes and least amount of rest occurring on nights three to five days before the moon reaches its brightest phase. They found a similar pattern in sleep data from another group of more than 460 people. Ahead of the full moon, it took people, on average, 30 minutes longer to fall asleep and they slept for 50 minutes less, said Leandro Casiraghi, the study’s lead author and a postdoctoral researcher in the Department of Biology at the University of Washington.
“What we did is we came up with a set of data that shockingly proves that this is real, that there’s an actual effect of the moon on our sleep,” Casiraghi said.
Stop springing forward, say sleep experts pushing standard over daylight saving time.
It’s not just the pandemic. The moon may be messing with your sleep, too.
Previous studies examining the moon’s effect on sleep have produced contradictory results. Some research has found minimal or no association between the lunar cycle and sleep, while other studies have demonstrated correlations in controlled settings. The findings of the Jan. 27 paper support existing observations that there is a link, Casiraghi said. But, he noted that the work he and his fellow scientists did is distinct from past research by a critical difference in methodology.
“This was real life,” he said, referring to the part of the study that actively monitored participants over lunar cycles. Other studies have primarily focused on retrospective analyses of data from people in sleep laboratories who were being evaluated for different research purposes.
The study involved analyzing the sleep patterns of three Toba Indigenous communities, also known as the Qom people, in northeast Argentina: one rural with no electricity access, a second with limited access and a third located in an urban setting with full access.
Horacio de la Iglesia, one of the study’s co-authors and a professor of biology at the University of Washington, said the communities were “ideal” to study because “they are all ethnically and socioculturally homogeneous, so it has become an outstanding opportunity to address questions about sleep under different levels of urbanization without other confounding effects.”
To track sleep, participants were outfitted with wrist monitors that logged activity, and information was gathered over a period of one to two lunar cycles.