Our sleep patterns are influenced by the full moon’s push and pull, according to the latest study published in Science Advances.
The results of the study show that, in the days before the full moon, people go to bed later and sleep less. A lunar cycle takes 29.5 days to complete.
Changes in each participant’s sleep time over the lunar cycle ranged from 20 to over 90 min and did not vary significantly between groups.
Study participants live in environments ranging from a rural situation with and without access to electricity in indigenous Toba / Qom communities in Argentina to a post-urban urban situation in the United States.
Solar and lunar data for the Ingeniero Juárez region through the recording dates were obtained from the NASA HORIZONS Web-Interface Propulsion Laboratory
Moonlight is usually available in the first hours of the night which is more likely to guide changes when it comes to sleep. In contrast, late moonlight should have little effect at night, when most people are asleep, asleep or long asleep.
While the sun is the most important source of light and synchronizes circadian rhythms for almost all species, moonlight also alters nocturnal activity in organisms.
The light of the moon is so clear to the human eye that it is perfectly reasonable to think that, in the absence of other light sources, this night light source could play a role in altering human night activity and sleep.
Before artificial light became available, moonlight was the only source of light sufficient to stimulate overnight activity; yet, evidence for altering bedtime through lunar phases is controversial.
The study shows that sleep starts later and is shorter on the nights before the full moon when the moonlight is available in the hours after nightfall.
Both bedtime and sleep time reflected a marked change throughout the lunar cycle that was evident in the entire population, as well as in the individual communities.
The study suggests that, in communities without access to electricity, lunar nights would be associated with increased nighttime activity and reduced sleep.
The strength of the lunar phase appears to be stronger on stronger sleep parameters as the access to electric light is limited.