A girl’s genes affect when she will get her first period, and many of these genes cause childhood weight gain, which is a risk factor for early puberty, according to a University of Cambridge study. Researchers noted that though the trend is not fully understood, early puberty is associated with an increased risk of adverse health conditions, including Type 2 diabetes, obesity, cardiovascular disease, and certain cancers. Conversely, delayed puberty has been associated with better adult health and a longer lifespan.
The authors recognized a “bidirectional causal relationship” between the age of a girl’s first period and her body size. “Greater early weight gain leading to earlier [onset of menses] and also earlier [onset of menses] leading to higher adult BMI (body mass index),” the authors wrote. The researchers also found that a few genes that influence the onset of menses are also linked to the age of menopause onset.
During a previous investigation alongside the University of Cambridge’s Medical Research Council Metabolic Diseases Unit, the researchers found a receptor in the brain that detects the body’s nutritional state. The receptor, MC3R, also regulates the timing of puberty and children’s growth rate. Other genes were observed to control the brain’s release of reproductive hormones.
The research team was able to develop a genetic score to predict whether a girl was likely to reach puberty very early or very late. Girls with the highest 1 percent .
