Girls are entering puberty much earlier than they used to, according to a new study published in the journal Pediatrics, and some begin maturing when they’re just eight years old. Researchers believe the trend is linked to the national obesity epidemic, since girls with a higher Body Mass Index (BMI) are more likely to develop breast tissue at an early age.
Those conclusions are the culmination of a long-term study that tracked more than 1,200 girls between the ages of six and eight. Researchers monitored the participants’ BMI and physical maturation from 2004 to 2011, and found that many of the girls began developing breast tissue in second grade. The average age for breast development was eight years and ten months for African-American girls; nine years and four months for Hispanic girls; and nine years and eight months for white and Asian girls. Heavier girls tended to be on the earlier end of that range, around eight years old, while girls with lower BMIs didn’t show signs of puberty until around age ten.
The study’s lead researcher, Dr. Frank Biro, concluded that obesity appears to be a “prime driver” behind early breast development. “BMI is, we found, the biggest single factor for the onset of puberty,” Biro told NBC News. Biro suggests that extra weight might trigger puberty because it leads the body to believe it already has enough energy and resources to sustain that process.
Learn more here http://www.cnn.com/2010/HEALTH/08/09/girls.starting.puberty.early/