Bad night’s sleep? The moon might be to blame
Report in Current Biology offers scientific evidence of the moon's effect on sleep
By Mary Beth O'Leary Posted on 25 July 2013
Many people complain about poor sleep around the full moon, and now a report just published in Current Biology, a Cell Press publication, offers some of the first convincing scientific evidence to suggest that this really is true. The findings add to evidence that humans — despite the comforts of our civilized world — still respond to the geophysical rhythms of the moon, driven by a circalunar clock.
"The lunar cycle seems to influence human sleep, even when one does not 'see' the moon and is not aware of the actual moon phase," said Dr. Christian Cajochen, a professor specializing in sleep and chronobiology at the Psychiatric Hospital of the University of Basel in Switzerland.
In the new study, the researchers studied 33 volunteers in two age groups in the lab while they slept. Their brain patterns were monitored while sleeping, along with eye movements and hormone secretions.
The data show that around the full moon, brain activity related to deep sleep dropped by 30 percent. People also took five minutes longer to fall asleep, and they slept for twenty minutes less time overall. Study participants felt as though their sleep was poorer when the moon was full, and they showed diminished levels of melatonin, a hormone known to regulate sleep and wake cycles.
"This is the first reliable evidence that a lunar rhythm can modulate sleep structure in humans when measured under the highly controlled conditions of a circadian laboratory study protocol without time cues," the researchers said.
[pullquote align="right"]This is the first reliable evidence that a lunar rhythm can modulate sleep structure in humans when measured under the highly controlled conditions of a circadian laboratory study protocol without time cues.[/pullquote]
Dr. Cajochen added that this circalunar rhythm might be a relic from a past in which the moon could have synchronized human behaviors for reproductive or other purposes, much as it does in other animals. Today, the moon's hold over us is usually masked by the influence of electrical lighting and other aspects of modern life.
The researchers say it would be interesting to look more deeply into the anatomical location of the circalunar clock and its molecular and neuronal underpinnings. And, they say, it could turn out that the moon has power over other aspects of our behavior as well, such as our cognitive performance and our moods.[divider]
Read the abstract
[caption id="attachment_18867" align="alignleft" width="150"]Mary Beth O'Leary[/caption]
Elsevier Connect Contributor
Mary Beth O'Leary is Press Officer and Associate Media Relations Manager for Cell Press (@CellPressNews), based in Cambridge, Massachusetts. She began her career at Cell Press as an Senior Editorial Assistant for the journal Cellbefore transitioning into a role as Marketing/Publicity Coordinator. In December, she moved into her position as Press Officer for Cell Press's 29 journals. A graduate of the College of the Holy Cross in Worcester, Massachusetts, she studied literature and art history.