New studies suggest changes in sleep time and onset due to lunar phases

New findings published in Science Advances It suggests that the human sleep cycle can change along the lunar cycle, regardless of whether the individual is in a rural or urban area.

When humans were hunter-gatherers, there were fairly simple rules for bedtime. I fell asleep as soon as the moon rose (unless I didn’t want to be devoured by lurking predators). That logic remained solid and fast for thousands of years. Until the advent of electricity made it possible to invent feats against circadian clocks such as clubbing (or more recently Netflix binge at 3 am).

Joint research between University of Washington (your), Yale University Group from Quirumes National University Argentina’s Sensorimotor Dynamics Lab shows that old habits die hard when it comes to moonlight and sleep.

A team led by Professor Horaciode la Inglesia of the University of Washington studied the sleeping habits of 98 indigenous Western Toba / com communities who maintained a hunter-gatherer community until the arrival of Spanish colonists in the 1500s. Today, Western Toba / Com is spread all over the place. The researchers selected three groups. One is a group living without electricity, one is a group with restricted access to lamps, and the last group is a group with free access to electricity. They asked if sleep time and onset depended on the lunar cycle among these three groups and predicted that such effects would be limited to those in a non-electric environment. Their predictions proved to be far from Mark.

Regardless of the urbanization of the setting, participants in a study that measured sleep with an actimetric bracelet recorded the shortest sleep and the latest bedtime 3-5 days before the full moon, showing uniform vibrations in their sleep patterns. I did. The authors write that this suggests that the participants’ bodies were naturally preparing to become more active in the brighter nights.

This produced some powerful changes, with participants sleeping on average about 50 minutes longer at peak vibrations.

The power of moonlight

The author’s first choice of urban environment, Engineer Juarez Formosa, northwest of Argentina, has a population of only 19,000. Can living in a vast city reduce the effects of the lunar cycle on sleep? To answer the question, researchers looked at another group using data from 464 UW college students whose sleep data was recorded as part of another study.Results of this group who lived in an unquestionable urban environment Seattle (Population: 776,000) also showed compliance with the flexion of the lunar cycle in their sleep habits.

Leandro Casiraghi, a postdoctoral fellow at the University of Washington, says the findings show ancestral adaptations to our sleep and wake cycle. Press release: “Assuming that the pattern we observed is an innate adaptation that allowed our ancestors to take advantage of this natural evening light source that occurred at a particular time in the lunar cycle. I will. “

Interestingly, no relationship was found between the time of awakening and the ebb and flow of the moon – de la Inglesia comment This is another aspect in which the effect of electricity on the circadian clock mimics the effect of moonlight. “In general, artificial light destroys the circadian clock in certain ways, which allows us to fall asleep late at night. It reduces our sleep. But in general, at least aggressively. We do not use artificial light to “advance” the morning, not to the point. These are the same patterns we observed here in the ebb and flow of the moon. “

Divided evidence

The findings of de la Iglesia add evidence to areas divided by the question of how the moon affects our sleep patterns. Some previous studies, even analyzing the same data from UW students, could not find a relationship between lunar peaks and falls and sleep time. In their treatise, the team could clarify the relationship by long-term mapping of lunar cycles, rather than just using direct comparisons of data from the full moon, full moon, and new moon stages. I suggested that.

Further research is needed to resolve these conflicts. It’s clear that there are many questions to answer.Casiraghi Summarize How Can These Questions Be Answered? “How Future Studies Need to Focus: Does It Work Through Our Natural Circadian Clock? Or Affects Sleep Timing Other signals to give? There is a lot to understand about this effect. “

reference:

Casiraghi L, Spiousas I, Dunster GP, etc. Lunar sleep: Synchronization of human sleep and lunar eclipse under outdoor conditions. Scientific progress.. 2021; 7 (5): eabe0465. Doi:10.1126 / sciadv.abe0465