Between the Full Moon and the Smartphone: The Disappearing "Menstruation" and the Rhythm of the Moon - A Subtle Clue Seen in the Cycle of the Moon and Women

A research team from the University of Würzburg in Germany analyzed long-term menstrual records of women and reported that before 2010, menstrual cycles were more likely to coincide with the full moon or new moon. However, since the proliferation of LED lighting and smartphones, this synchronization has significantly weakened. The synchronization tends to remain only in January, when the gravitational forces of the Earth, moon, and sun are strongest. Artificial light, particularly blue light, strongly affects the biological clock, potentially shortening cycles and disrupting synchronization. However, this is a correlation, and causation has not been established. Related studies also indicate trends such as shorter sleep before a full moon and synchronization between mood fluctuations in bipolar disorder and lunar phases. On social media, reactions range from practical voices acknowledging the correlation but questioning causation, expressing desires for "more dark nights," to skeptical voices dismissing it as "mere coincidence." While careful interpretation of the research is necessary, revising lifestyle habits to reduce artificial light at night could be beneficial.