You may have heard people justify a bad night of sleep because ‘it was a full moon’, and immediately dismissed it as a myth. Well, think again.
The moon affecting our sleep is not as weird and irrational as it sounds. In fact, it’s not even unheard of in the animal kingdom, as this is known to happen in many other organisms, from small worms to large marine animals, and can not only affect their sleep, but also their reproductive cycles. It even has its own name: the circalunar rhythm.
But to see if it could happen in humans too, a group of researchers from University of Basel, Switzerland, followed a group of patients who, like normal human beings, fell asleep every night, and every time gave the scientists their opinion on how well it went. Most agreed that on the day of or close to full moon, the sleep quality was lower and they felt less rested. But this could be a subjective or biased opinion by the patients. So the scientists backed this up with the most undeniable proof of all: science.
They measured the hormone levels, brain activity and any eye movements before, during and after falling asleep. In case you’re confused about why bother measuring eye movement; it is because during REM phase, where we actually ‘rest’, our eyes subconsciously move around (in fact, REM phase stands for Rapid Eye Movement phase). After conducting this research at different times of the month, and therefore at different stages in the moon cycle, what they found only supported what the people had said themselves: there was a decrease, of up to 30%, in the people’s brain patterns during sleep. Not only was the quality worse, but it was also shorter, as they took 5 more minutes to become unconscious and in total were deprived of almost 20 minutes of blissful sleep.
This could’ve all been due to a decrease in the levels of melatonin, a very interesting hormone which can be found in animals that somewhat ‘predicts’ when it is going to get dark and prepares us for sleep, so a lack of it could lead to us not sleeping as deeply.
But researchers don’t know how the moon can even affect the amount of this hormone in our body and can end up causing the other symptoms. It’s not the presence of moonlight, as this was eliminated by keeping the test subjects in closed rooms. So this leaves the two most plausible ideas being either that the moon’s gravity somehow manages to affects us even though it is extremely weak at such a large distance, or that humans have a physiological clock inside of them which keeps track of the moon cycles. Although this may sound just bizarre, it already exists; but instead of with the moon, it uses the Sun. You may have heard of it: it’s called the circadian rhythm and it has a great effect on us as thanks to it, our body knows how to behave at the different times of the day.
The test was only done on 33 people, quite a small sample regardless of how standardised the whole procedure was. So in future investigations, larger groups of people should be investigated to not only support these scientists’ hypothesis, but maybe to even find out the mechanism by which the moon manages to ruin a good night’s sleep.