Many myths and legends suggest the phase of the moon can affect behaviors. Folklore about werewolves even suggests it can have transformative powers. Though we may not change species according to the moon cycles, there is research to suggest they do affect us.
This poses the question: Do lunar cycles affect how you sleep? To answer that question, we first have to understand what lunar cycles are all about.
What are the Different Moon Phases?ย
The moon goes through different โphasesโ that repeat every 29.5 days. These phases are defined by how much of the moon is visible from earth. It is these phases that are referred to by the terms โlunar cyclesโ or โmoon cycles.โ
According toย NASA, โBecause of the tilt and shape of its orbit, we see the moon from slightly different angles over the course of a month.โ The moonโs phases range from a full moon โ thatโs when the moon looks like a full circle โ to a half moon, small crescent, and then a new moon, where the moon isnโt visible at all.
Do the Moon Phases Impact Sleep?ย
According to some research, there may be a small link between the moonโs phase and how well people sleep.
It is hypothesized that the extra light emitted earlier in the evening and afternoon hours, leading up to the full moon, can create a change in our circadian rhythm, which will affect our sleep. The lunar cycle seems to affect both quality and quantity of sleep, similar to what we see inย shift workersย and those suffering from jet lag who areย exposed to light at irregular times.
In aย recent study, researchers from the University of Washington studied two groups: First the indigenous Toba/Qom communities in Argentina, and later college students in Seattle. They found a link between the waxing full moon and the shortest amount of sleep. Both groups hadย the latest bedtimes forย about three to five nights leading up to the full moon.
Within the indigenous Toba/Qom community, the researchers followed three specific segmented groups: one very rural segment with virtually no access to electrical light, one moderately rural segment with 24 hour access to minimal electrical light, and one urban group with access to lights at home and within the community setting โ the Seattle college students fell into this group, too.
These findings indicated that the moonโs phases do affect sleep, and that the more limited oneโs access is to electrical light, the stronger the moonโs effectย on sleep.
Leandro Casiraghi, UW postdoctoral researcher in the Department of Biology and the lead author of the study said, โWe hypothesize that the patterns we observed are an innate adaptation that allowed our ancestors to take advantage of this natural source of evening light that occurred at a specific time during the lunar cycle.โ
The same researchers discovered that the new moon, or dark phase of the moon, also created a smaller but noticeable change in sleep patterns in the two more rural segments of the Toba/Qom communities, suggesting that the sleep changes may also be caused by something like the moonโs maximal gravitational pull rather than by the full moonโs light. More research is needed to fully understand these complex sleep changes.
According toย NASA, humans experience the strongest gravitational pull during the full and new moons. At full moon, the moon and sun are essentially in a straight line on the opposite side or the same side of the earth respectively, and in both cases, the gravitational forces combine to create a pull on the earthโs surface.
How the Moon Can Impact Sleepย
Many people feel more restless, have difficulty falling asleep or getting up at regular times and report more vivid dreams during the full moon. Studies show that the full moon does affect REM sleep, melatonin levels, and it inhibits our sleep efficiency in general.
Restlessness and more vivid dreamsย
Psychologist Richard Wiseman from the University of Hertfordshire, UK,ย analyzed the resultsย of 1000 volunteers who listened to specific sounds that his team played as they slept. Wiseman discovered that for about a week surrounding the full moon, the content of our dreams are noticeably, โmore strangeโ. He went on to describe that, for instance, โsomeone might dream that they are flying on a dragon, then get off the dragon and go have a coffee with George Clooney, while some people dreamt that they were superheroes.โ Professor Wiseman also notes that, โour ancestors may have huntedย when the moon was full, with the result that we still find it hard to settle on bright nights.โ
Difficulty falling asleep or getting up at regular timeย
Results from a highly controlled Swiss study, where participants were put in sleep chambers with no access to windows, electronics, or had the ability to know what timeย of day it was for three and half days around the full moon,ย showed that:
- They slept 20 minutes less overall.
- They took 5 minutes longer to fall asleep.
- They had a 30% decline in brain activity that relates to deep sleep.
- They had lower levels of melatoninโwhich is our master regulator hormone of sleep and wake cycles. When melatonin is lowest, we tend to be awake and when it is highest, we become sleepy.
- The participants reported feeling less rested during the same period.
Meanwhile, in aย smaller studyย performed with men and women in Surrey England, women had shortened sleep and less REM sleep around the full moon, while menโs REM slightly increased during the same period.
RELATED:ย Why Are Some People โMorning Peopleโ And Some Are โNight Owlsโ?ย
Why Canโt I Sleep During a Full Moon?ย
In oneย study, researchers analyzed data from 5,812 children in 12 countries who were aged 9 to 11 years. According to Psychology Today, the researchersย discoveredย that โChildren slept an average of 4.9 minutes less during the time of the full moon, compared to the timeย of a new moon, an average 1 percent reduction in total sleep time.โ
Scientific American reported on another study of 33 individuals, which found that โaround the full moon, humans get less shut-eye and their slumber is not as deep, even if sleep is restricted to windowless rooms free of environmental and time-based cues โ such as those found in a sleep lab.โ
Study author Christian Cajochen, from the Psychiatric Hospital of the University of Basel in Switzerland, told CNN, โIf you ask people, at least in Switzerland, about 40 percent report feeling the moon during sleep, or they blame the full moon for bad sleep.โ Researchers arenโt totally sure what might cause the alleged connection between sleep and lunar cycles, but it could be related to our circadian rhythms.
Circadian rhythms are mental, physical, and behavioral changes that follow a cyclical 24-hour pattern that respond primarily to light and dark. Most living things, including animals, plants, and microbes are affected by circadian rhythms.
It is theorized that the moonlight affects circadian rhythm in a similar way that exposureย to electrical nighttime light does; by inhibiting melatonin synthesisโa key hormone that is produced to help us sleep. It may also be a leftover effect of our ancestorsโย harmony with the lunar cycle.
Scientists know that available moonlight changes formulaically throughout the moonโs cycle depending upon the time of moonrise, which is approximately 50 min later every day. The theory is that there is extra light available to us just after dusk, as the moon waxes toward full, because for these three to five days the moon is higher in the sky in the late afternoon and early evening instead of at its brightest in the middle of the night. Belief is that access to this early evening light allowed our ancestors to do moreย foraging and hunting on these nights, unlike nights where the sky was darker.
A recent study by the University of Washington showed how the moonโs 29.5-day cycle affects our sleep patterns through ourย circadian rhythm. This study shows a clear indication that for three to five days before the full moon, we see the most disturbed sleep across all populations, whether they live in rural environments with less access to electric light or urban dwellers who tend to have an abundance of electric light in the evening. Researchers noted that people living in urban environments did have lessย fluctuation in sleep than those living in more rural settings, likely because the urbanย dwellers had consistent exposure to electrical light at nightย through street lamps and other city light pollution, so their sleep valleys and peaks wereย more suppressed.
Menstrual function has an effect on the circadian rhythm too, and it is also intimatelyย related to the moonโs 29.5-day cycle. Aย long-term studyย done on a group of 22 women of varying ages found that all of the women (apart from three who lived in more urbanย environments and were self-reported โnight owlsโ) had menstrual cycles that were synced with the moon cycles at times, either beginning around the new or full moonโ full moon menses were the most prominent.
This study found that as women age or are exposed to more artificial nocturnal light, the menstrual cycle shortens or lengthens and loses this synchronicity to the lunar cycle. In ancient times, humansโ reproductiveย behavior was probably more synchronized to the moon, but our modern lifestyles, including later sleep onset and exposure to electrical light has likely changed this.
Whatโs clear is that more research is needed to determine whether our sleep is actually affected by lunar cycles. So far, preliminary research suggests the moonโs cycles might impact our sleep โ but this research is hardly definitive.
The good news is no studies have confirmed that a full moon is more likely to turn you into a werewolf.
How to Sleep Better During a Full Moonย
We have no control over the waxing and waning of the moon, but we do have the abilityย to change specific environmental factors that may help us sleep better in general, and during the full moon. Here are some sleep hygiene tips to help you sleep better:
- Invest in blackout blinds. This will block ambient light from street lamps, cars, or a bright full moon.
- Try a sleep mask. This is a great option for those who travel a lot or donโt have access to blackout blinds.
- Try a bath before bed. Cooling down after the bath is what signals sleepiness. Take the bath one to twoย hours before your target bedtime. It takes our bodies about 20 minutes toย respond to a warm bath by cooling down our core temperature. Maximum sleepiness occurs when core body temperature is at its lowest.
- Limit yourย exposure to blue lightย for a few, or at least two hours before turning in to ensure a deep sleep.
Final Thoughtsย ย
There is still a lot we donโt understand about how the moon affects us, however the science is clear that there is a small, but direct link between the moonโs cycle and our sleep. Circadian rhythms, REM, melatonin production and menstrual cycles have allย been proven to be affected by the lunar cycle.
Recent evidence points to possibilities that both the early evening light leading up to the full moon and the moonโs gravitationalย pull may be a key influencer of our sleep during the full and new moons. Perhaps โlunar rhythmsโ were passed down from our ancient ancestors who became attuned to the changing moon based on their altered daily practices around the moonโs cycles.