A recent study conducted by a team of reproductive researchers from various institutions in France and the U.S. has shed light on the regulation of the monthly ovarian cycle in women, indicating that it is predominantly influenced by the circadian rhythm. The findings, published in the journal Science Advances, are based on an analysis of data from thousands of women in Europe and the U.S.
For centuries, scientists have been intrigued by the mechanism governing the ovarian cycle, with one prevalent theory suggesting a connection to the lunar cycle. Charles Darwin proposed that this link originated when early humans resided near the seashore, where the tides played a significant role in daily patterns.
However, recent research led by Würzburg chronobiologist Charlotte Förster revealed temporary synchronization between women’s menstrual cycles and lunar cycles. The latest study by the research team did not find substantial evidence supporting a lunar influence, leading them to propose that the circadian rhythm likely plays a pivotal role in regulating the ovarian cycle.
The circadian rhythm encompasses the physical, mental, and behavioral changes that organisms experience over a 24-hour cycle. While it is widely known to affect sleep patterns, it can also be influenced by external factors such as the lunar cycle, which may cause individuals to stay up later or sleep less before a full moon.
To investigate the mechanism underlying ovarian cycle regulation, the researchers analyzed medical records of over 3,000 women from Europe and North America, covering a total of 27,000 ovarian cycles. By tracking the onset of each cycle for the participants, they observed minimal correlation between cycle initiation and lunar phases.
Instead, the study uncovered instances of “phase jumps,” where disruptions in the cycle timing prompted the body to adjust its clock rhythm over several months to restore the cycle to its usual pattern. Analogous to how the circadian rhythm responds to jet lag, the researchers suggest that the circadian rhythm is a more plausible determinant of ovarian cycling.
In conclusion, the study provides compelling evidence that the circadian rhythm is intricately linked to the regulation of the ovarian cycle in women, highlighting the significance of internal biological mechanisms in governing reproductive processes. Further research in this area could offer valuable insights into women’s health and fertility.