Boosted plant growth, disruption of the female menstrual cycle, increased risk of natural disasters:since the dawn of time, humanity has lent a strong influence to the full moon, for worse and for better. And when it comes to our sleep, science has decided:yes, the full moon disturbs it. Explanations.
The full moon is surrounded by a sulphurous reputation. Popular beliefs lend him powers as frightening as they are fascinating, which notably gave rise to the myth of the werewolf. It has also long been accused of disturbing sleep, and the fact has proven scientifically correct at the dawn of the new millennium.
Between 2000 and 2003, researchers at the University of Basel, Switzerland, looked into the link between age and sleep quality. A group of 33 volunteers aged 20 to 74 were placed in an isolated environment and observed for 64 nights, distributed according to the lunar calendar. It was by chance, while chatting over a drink, that the team thought of observing a possible influence of the full moon.
By retrospectively analyzing various results – structure of sleep, measurement of melatonin and cortisol secretion or electroencephalogram of sleep with non-rapid eye movement (EEG) – they were able to establish that the phases of deep sleep were shortened by 20 to 30% during full moon nights.
Although the explanation remains to be clarified, they then bring to light an astonishing fact:the rate of secretion of melatonin (the sleep hormone) was 50% lower than the usual rate. Concretely, this translated into about 20 minutes less sleep in the study, and a 15% loss in sleep quality.
In 2020, it is the turn of researchers from the University of Washington (United States) to deliver their conclusions, and it is formal:during the full moon - and the 3 to 5 days preceding it -, falling asleep is delayed by 30 minutes on average, and sleep time is shortened by 46 to 58 minutes. These data are the most accurate so far, because they are not based on the feelings of the volunteers, but on measurements made using different monitors.
American researchers lean towards a simple explanation:during the full moon, the satellite is completely unveiled and it generously reflects sunlight. This brightness disrupts the circadian rhythm on which our biological clock is based. However, the effects of light alone cannot fully explain the effect of the full moon on sleep. This study did indeed reveal a “semi-lunar effect”:variations in sleep occurring every 15 days – halfway through the 29.5-day lunar cycle. Phenomena that are currently misunderstood cannot therefore be excluded.
If the effects of the full moon on sleep retain their share of mystery, it is now established that they are very real. If you are sensitive to it yourself, a few tips can help you sleep better during these periods.
To take full advantage of the deep sleep phases, even though they are shorter, and to limit the risk of untimely awakening, try to start by limiting the exposure of your sleeping environment to moonlight as much as possible. It is also essential to have good bedding. The new generation mattresses now offer significant comfort, but to get the most out of them, it is also recommended to use a pillow adapted to your morphology and your preferred sleeping position.
During the full moon phases, more than ever, it is important to ensure a healthy lifestyle, avoiding an overly hearty dinner. Also be sure to avoid alcohol in the evening, and limit your consumption of stimulating substances, such as coffee. Finally, avoid screens the hours before bedtime, whose blue light very similar to that emitted by the sun contributes to disturbing the circadian rhythm! Prefer a calm activity, such as reading or meditation.
