News Article: Increasing Numbers of Girls are Entering Early Puberty

A recent study on breast development in young American girls has shown that higher numbers of girls are beginning puberty at ages 7 and 8 than there were 30 or even 10 years ago. The study was published in an online paper called Pediatrics.

The data examined was gathered from 1,239 girls between the ages of 6 and 8 from New York City, Cincinnati, and the San Francisco Bay area. The data showed higher proportions of girls with early breast development than were found in studies done 10 and 30 years prior.

Of the five stages of breast development, known as the Tanner Breast Stages, 10.4% of white, 23.4% of black, and 14.9% of Hispanic girls had reached breast stage 2 or higher by age 7. And by age 8, 18.3% of white, 42.9% of black, and 30.9% of Hispanic girls had reached breast stage 2 or higher. The percentage of early breast development in white girls showed the greatest increase when compared to earlier studies.

Lead author of the study, Dr. Frank Biro, and his colleagues said their study was not representative of all girls in the U.S. and that further research would be needed to gain an accurate sample. However, Biro asserts that if this is an accurate population-wide trend, it could have important health implications that would need to be considered.

Previous studies have shown that girls who reach puberty earlier run a higher risk of breast cancer later in life. They are also more likely to engage in risky behavior. Also, due to the fact that girls who enter puberty earlier are psychologically younger than they appear and may be expected to act older, their emotional and mental development can be affected. Other studies have shown that girls who enter early puberty are at higher risk for depression as well.

As for what the reasons for these findings could be, researchers could only speculate. A correlation was found between BMI and breast development; more obese girls with higher BMIs tended to reach puberty earlier than girls with lower BMIs. Biro said that increasing obesity rates could have something to do with earlier puberty rates.