Sleepless night? Could blame it on the moonlight!

By Anna Tiley

There really is no doubt about it; I come from a family of major sleepaholics. We really relish a good night’s sleep and, particularly among the Mexican relatives, it’s common knowledge that there’ll be hell to pay if you wake someone up mid-siesta!

However, the odd sleepless is night is inevitable and sometimes there seems to be no explanation as to why it happens. So what could cause it?

According to a study published last year, how well we sleep may be influenced by the moon’s lunar cycle.

Moon by  Yu-Ching ChuThe study was carried out by a group of German scientists who investigated the sleeping patterns of 33 healthy men and women at different times of the year. Participants weren’t told exactly what the study was investigating; all they knew was that the scientists were recording their sleeping patterns. This was done by monitoring a number of factors while they slept, including brain activity, leg and eye movements, and oxygen levels.

Surprisingly the study showed that during a full moon it took the participants an average of 5 minutes more to get to sleep. Additionally, total sleep duration was about 20 minutes less and the amount of deep sleep decreased by 30%, compared to other nights

However, last month another paper was published by a second group of scientists who claimed that these results may be incorrect.

The scientists repeated the study, but used over 1,500 volunteers. From the results collected, the scientists concluded that there wasn’t a link between sleep and the lunar cycle.

So what does this show?

At the moment there isn’t enough evidence to make a conclusion on this topic. Although we know that the lunar cycle does affect marine animals such as fish, there is not enough scientific evidence for whether it affects terrestrial animals like humans.

It makes sense for fish and other sea creatures to adapt to the lunar cycles – after all, the moon drives changes in their aquatic habitat, such as tidal fluctuations However, if it also affects us, what evolutionary benefit would it have?


Image: Moon by Yu-Ching Chu under Creative Commons License