A new study published in the journal Current Biology provides the first scientific evidence that the lunar cycle can influence human sleep.

Study lead author Dr Christian Cajochen of the University of Basel’s Psychiatric Hospital with colleagues 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 results show that around the full Moon, brain activity related to deep sleep dropped by 30 percent. The participants also took five minutes longer to fall asleep, and they slept for twenty minutes less time overall.

They 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.

Dr Cajochen said: “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.”

“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.”

“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,” Dr Cajochen and colleagues said.

“It would be interesting to look more deeply into the anatomical location of the circalunar clock and its molecular and neuronal underpinnings.”

“And, 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.”

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Bibliographic information: Christian Cajochen et al. Evidence that the Lunar Cycle Influences Human Sleep. Current Biology, published online July 25, 2013; doi: 10.1016/j.cub.2013.06.029