Boys Hitting Puberty Earlier
October 21, 2012

Researchers Discover That Boys Are Hitting Puberty Earlier

redOrbit Staff & Wire Reports — Your Universe Online

Just as previous research reported that girls in the U.S. were reaching puberty earlier in life, a new study reveals American boys are also showing the first signs of sexual maturity at a younger age than in decades past.

The research, which was led by Marcia Herman-Giddens of the University of North Carolina's School of Public Health, discovered that males are beginning to sexually develop six to 24 months earlier than the accepted medical standard, CNN's Jacque Wilson reported on Saturday.

Herman-Giddens, who originally documented early puberty in females back in 1997, and colleagues recruited more than 200 medical professionals throughout the U.S. to assist in their research. Between the years of 2005 and 2010, those individuals examined over 4,100 boys, aged six to 16, from 41 different states, Wilson said.

They recorded information about the size of the boys' testicles, as well as the growth level of pubic hair, and then "assigned each boy's data to one of five stages -- Stage 1 being pre-puberty, Stage 2 being the onset of puberty and Stage 5 being adult maturity," the CNN reporter added. "They then compared the ages and puberty stages of all the boys. The rigorous study was designed to report on only physical changes, not hormonal."

According to Paul Harris of The Observer, prior to this research, the accepted average age at which boys reached puberty was 11.5. Herman-Giddens's team discovered, however, that the average African-American boy began showing signs of puberty at just a little over nine years of age, while white and Hispanic youngsters began reaching sexual maturity shortly after reaching the age of 10, Harris said.

"The study does not pinpoint what exactly is driving the trend toward earlier puberty, nor does it identify an underlying mechanism that might explain any racial differences," said Alan Mozes of HealthDay News. "However, the finding builds on what most experts consider definitive research from the 1990s, which confirmed that American girls are also entering puberty at a younger age today than in decades past."

Their findings were published online Saturday by the journal Pediatrics, and will appear in the November print edition of the publication.

"When I was studying the subject in girls, I wasn't surprised with the findings because I was seeing it every day in clinic," Herman-Giddens, an adjunct professor of maternal and child health at the University of North Carolina, told Mozes. "And it's also more obvious, since breast development is the first sign of puberty and everybody can see it."

"By contrast, testicular development in boys is very subtle. To the point where even the boy himself doesn't necessarily notice it at the beginning," she added. "And also the environmental issues that we have long associated with earlier puberty in girls, such as being overweight and environmental exposure to endocrine [hormone]-disruptive chemicals, would actually be expected to slow puberty in boys, not hasten it. So, to see the same thing in boys is actually somewhat surprising."