Researchers have identified multiple reasons why girls begin their periods at an earlier age. A recent study indicates that the onset of menstruation is occurring sooner, along with changes in how long it takes for cycles to stabilize.
These findings were published in the journal JAMA Network Open.
The research utilized data from the Apple Women’s Health Study, which involved collaboration between researchers from the Harvard T.H. Chan School of Public Health and the National Institute of Environmental Health Sciences (NIEHS), with Apple contributing to the study.
Analyzing data from 71,341 participants who used iPhones and Apple Watches, researchers found that girls born between 2000 and 2005 tend to start their periods around age 11.9, while those born from 1950 to 1969 began menstruating at approximately age 12.5. This study highlights a trend of decreasing age at first menstruation over generations, suggesting possible shifts in the factors influencing the timing of puberty.
These trends may be associated with growing health issues and disparities in the United States. The study revealed that individuals who identified as Asian, non-Hispanic Black or multiracial reported an earlier onset of menstruation compared to those identifying as White. Dr. Zifan Wang, the lead researcher, noted that newer generations born between 1950 and 2005 are menstruating earlier and that the time taken for their cycles to regularize is increasing.
Dr. Wang underlined the importance of these findings, as early menstruation and irregular cycle patterns could indicate future health concerns that may need medical intervention. He stressed that these changes might lead to heightened health problems and disparities in the U.S., highlighting the need for public health awareness and action regarding these trends.
Dr. Eve Feinberg, an associate professor of obstetrics and gynecology at Northwestern University’s Feinberg School of Medicine in Chicago, mentioned that menstruation is a crucial indicator of overall health. She explained that consistent menstrual cycles are vital since irregularities can hint at underlying health issues. Additionally, Dr. Feinberg pointed out the difficulties young girls might face with early puberty, including potential mismatches between their physical and emotional development, which could result in social and psychological challenges.
The research team noted that various factors could lead to the early onset of menstruation. They indicated that being overweight heightens the chances of starting puberty earlier, suggesting a potential link between obesity and early menstruation. With an increasing number of children in the U.S. classified as overweight, researchers propose this trend could be a factor in the younger ages at which girls begin their periods.
Moreover, the team discussed additional influences that might affect the timing of puberty, such as environmental factors, nutrition, stress, and negative childhood experiences. These elements may be significant in the observed shifts in the onset of menstruation and warrant further examination.
The researchers also recognized that body weight at the time of first menstruation plays a crucial role in this trend. It is essential to understand the implications of early menstruation concerning health concerns. While there are observed trends of earlier menstruation in the U.S., data on the variations tied to sociodemographic factors and body mass index (BMI) is limited. Furthermore, there has been little research into the transition from the first menstruation to achieving regular cycles, which also has health ramifications.
The findings revealed an overall decline in the average age at which menstruation begins, leading to more individuals experiencing earlier menses and fewer achieving regular cycles within two years. This trend was especially pronounced among certain racial and ethnic minority groups, along with those from lower socioeconomic backgrounds.
Further analysis suggested that BMI accounted for a significant portion of the changes observed in the onset of menstruation. These results highlight potential contributors to health challenges and inequalities in the United States related to puberty timing.
