People have always believed that the moon has an effect on moods, disasters and accidents. Many blame the moon for increased fighting or strange behavior in people. A new study published from the University of Washington found that the moon can also affect sleep. Researchers from Washington University worked with scientists from National University of Quilmes in Argentina and Yale University to investigate sleep cycles in humans.
Researchers It found that people’s sleep cycles oscillate during the lunar cycle of 29.5 days. In the days leading up to the full moon, people sleep late in the evening and sleep for shorter periods of time. Differences in both the time of sleep onset and the duration of sleep were observed in both urban and rural areas.
The observations were made in different people in different settings ranging from indigenous communities in northern Argentina to college students in Seattle, Washington. The variance of the sleep cycle was the same regardless of the access to electricity that people had although the differences are less pronounced in individuals in urban settings. Researchers believe that the ubiquitous spread of this pattern could indicate that natural circadian rhythms are in sync with the phases of the lunar cycle.
Sleep patterns were recorded among 98 individuals living in three Tuba-Qom indigenous communities in the Argentine province of Formosa using wrist monitors. The communities used in the study differed in their access to electricity during the study. One rural community does not have electricity, another society has limited access to electricity, and there is a third community in an urban setting with full access to electricity. Sleep data were collected from one to two lunar sessions.
Participants in the three communities showed the same sleep oscillations as the moon advanced through its 29.5-day cycle. Depending on the community, the amount of sleep across the lunar cycle varied an average of 46 to 58 minutes on sleep times that changed by about 30 minutes. People usually have the newest sleep times and the shortest sleep period at night from 3 to 5 days before the full moon. The same oscillations were found in data from 464 Seattle Area College students.