How the Full Moon Can Disrupt Our Sleep

The closer the full moon approaches, the more its radiation becomes important and the more it disturbs the rhythm of sleep. In populations that do not have access to electricity and where the Moon is the main light source, the waking time is extended by almost an hour.

THE ESSENTIAL

The Moon disrupts our sleep cycle with its radiation.
The closer the full moon approaches, the more powerful its effects on sleep.
In the 3 to 5 days preceding the full moon, the waking time can vary up to 58 minutes in populations that do not have access to electricity for lighting.

The Moon has a lot of influence on the Earth and everything that composes it. This ranges from the rhythm of the tides, to the menstrual cycle of women, through the adjustment of the reproductive cycle of animals, as well as our sleep. In a study published on January 27, 2021 in the journal Science Advances, researchers from the universities of Yale, Washington (United States) and Quilmes (Argentina) have demonstrated that the Moon has an influence on our sleep cycle. The closer we get to the Full Moon, the later we stay up and sleep less.

In order to determine if the moon phase really has an influence on sleep, the researchers conducted a study among three Western Toba/Qom communities in the Argentine province of Formosa. Once exclusively hunter-gatherers, these geographically dispersed indigenous communities share a recent historical past and live at very different levels of urbanization. According to them, the fact that some people do not have access to electricity but only light up by moonlight should increase their nocturnal activity and decrease their sleep.

Up to an hour delay due to the full moon

Each of the communities has its properties; the first is urban and one has access to electricity in his daily life, the second is rural with more limited access to electricity while the third, also rural, does not have electricity. Looking at the results, the researchers found differences in sleep depending on moonlight exposure.

Thus, compared to the longest nights they had, populations without electricity but exposed to moonlight slept almost an hour less (58 minutes) as the full moon approached. This difference is reduced to 52 minutes in the rural population with access to electricity and shrinks to 46 minutes for the urban populations.

In the days before the full moon, participants slept later and shorter under the effect of moonlight. Ultimately, moonlight stimulates nocturnal activity and inhibits sleep in people who do not have access to electricity. On the other hand, populations that can light themselves artificially are less subject to this effect.

“Sleep duration and onset time showed clear modulation throughout the lunar cycle, which was evident across the population as well as within individual communities. The peak in sleep time and the trough in sleep duration occurred 3-5 days before the night of the full moon. The shift in sleep hours suggests negligible variation across the lunar cycle”, note the researchers in their conclusion.