Until a few decades ago, girls began puberty at about age 11 and completed puberty by about age 13. Now, it is more common to see puberty in girls beginning at about 9 and 10 years of age and sometimes as early as 6 or 7 years of age. Researchers are investigating why puberty starts earlier in girls than it used to and what type of implications this may have for a person's health.
What is Causing the Early Onset of Puberty?
Genetics is one of several factors that influence the onset of puberty in girls. One study showed that girls with two copies of a specific version of a gene that breaks down testosterone began puberty earlier than girls with a different version of the gene.
Some researchers hypothesize that the increasing prevalence of obesity in young girls could be one factor triggering puberty. These researchers found that girls who were overweight or obese started puberty earlier than girls who were not.
Other researchers hypothesize that pollutants could be triggering the onset of early puberty. For example, there are pollutants called hormone mimics that behave like natural hormones. Some pollutants, called hormone disrupters, prevent natural hormones from functioning normally.
Most hormone disrupters interfere with the sex hormones. Such hormone disrupters prevent normal production of testosterone in males or increase the chances of sexual abnormality in females. Examples of hormone disrupters include phthalate (THAH-late) esters (found in plastic toys, vinyl flooring, and cosmetics), and bisphenol A and polybrominated biphenyls (used to make plastic food and drink containers).
Many factors influence the age at which a girl begins puberty. Researchers are studying why girls today are starting puberty earlier than girls 30 years ago and what effect this may have on their health.
Does Early Puberty Affect a Person's Health?
Researchers have studied the effect of early puberty on a person's health. One study investigated 1,811 sets of female twins in which one or both of the twins developed breast cancer as adults. The twin who entered puberty first was five times more likely to develop breast cancer first. The link was stronger if menstruation started earlier than average. As a result of these and other findings, many scientists and physicians are calling for more research to determine the causes of early puberty.
Was this article helpful?