Melatonin is a hormone that is produced in the pineal gland. When the retina in the eye doesn’t since light, it sends a messenger to the suprachiasmatic nucleus (SCN) in the Hypothalamus in the brain to secrete more melatonin from the pineal gland to help with the circadian rhythm for sleep ( Tortora. Gerard ). When it’s dark our bodies have higher levels of melatonin and when theirs light lower levels are secreted. So, during lunar phases, when the full moon is in the position that is aligned with the earth, sun, and moon so that the sun light part of the moon is facing earth causing it to be brighter at night have an effect on melatonin?
In one study by Rhaman, the rabbit fish were measured for melatonin during different phases of the moon. During natural light that he defined saying 12 hours of light and 12 non- light, the fish had a steady pattern. In the constant light the levels were lower, and in constant dark fish’s levels were high. When the fish were studied under the moon phases, the new moon had the higher levels of melatonin then the full moon (Rahman, Saydur). In this article, there is a relationship between moon phases and melatonin, just not with the effect of the brightness of the full moon.
No correlation was found in the study The Lunar Cycle: Effects on Human and Animal Behavior and Physiology (Zimeck, M). It studied the myth of increases of reproductions, birth rates, hospital visits, suicides, and car wrecks during a full moon. The full moon doesn’t have effects on human behavior or the increased or decreased melatonin secretions in the body. A shift workers study was conducted on night shift workers and found that given melatonin four hours before a eight hour sleep cycle was effective in promoting adaptation to night work (Sharkey, Eastman). It has been shown that melatonin does phase advance our circadian rhythms four hours before our normal sleeping time (Sharkey, Eastman). To conclude, the extra light at night does not cause human behaviors, but taking melatonin during the day can increase adaptation to sleeping during the day.
Citations:
Rahman, Saydur. Effects of Moonlight Exposure on Plasma Melatonin Rhythums in the Seagrass
Rabbit Fish, Siganus Canaliculatus. Journal of Biological Rhythums. Vol 19.4. 325-334.
2004
Sharkey, Katherine., Eastman, Charmane., Melatonin Phase Shifts Human Circadian Rhythms in a Placebo- Controlled Stimulated Night-Work Study. American Journal of Physiology. 2001. July 2013.