Study finds ovarian cycle is regulated by circadian rhythm
Last reviewed: 14.06.2024
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Researchers from France and the United States working in the field of reproductive medicine have found that women's monthly cycles are most likely associated with a circadian rhythm. In an article published in the journal Science Advances, scientists analyzed data on thousands of ovulatory cycles recorded by women in Europe and the United States.
The question of what regulates the ovulatory cycle has long been a subject of scientific controversy. One of the most common hypotheses was the idea of a connection with the lunar cycle. Charles Darwin theorized that this connection arose when people lived near the sea coast and their daily lives were closely related to the ebb and flow of the tides. Three years ago, a team of scientists led by chronobiologist Charlotte Förster from Würzburg discovered that women's menstrual cycles can temporarily synchronize with the phases of the moon. However, in the new study, the team found little evidence of a moon influence and suggested that the circadian rhythm most likely controls ovulatory cycles.
The circadian rhythm is a 24-hour cycle of physical, mental and behavioral changes that is common to all living things, including humans. For example, the circadian rhythm regulates sleep, making people sleepy at certain times of the day. It is also known that the circadian rhythm can be affected by the lunar cycle: people may go to bed later and sleep less on the nights before the full moon.
To study the mechanism that controls ovulatory cycles, researchers collected medical data from more than 3,000 women in Europe and North America, covering 27,000 ovulatory cycles. They tracked the first day of each cycle and found no significant correlation between the start of the cycle and the phases of the moon.
However, scientists have discovered another pattern: many cases where something disrupted a woman's normal cycle, and her body adapted, changing its rhythm over several months to restore the normal cycle. They compared this phenomenon to how the circadian rhythm adapts to jet lag. These observations suggested that the circadian rhythm plays a more important role in regulating ovulatory cycles than the lunar cycle.
Thus, the results of the study indicate that the circadian rhythm, and not lunar phases, is the main factor influencing ovulatory cycles in women.