Why are girls starting puberty at a younger age?

Girl jumping rope
A young girl skips along the north pier on 17 June, 2006, Blackpool, England.
Christopher Furlong/Getty Images

Researchers are finding a growing trend in young girls starting puberty at an earlier age. While doctors don't know if the earlier development is linked to environmental stressors or outside hormones, everyone agrees that it's leading to problems. For these girls, development at an earlier age can lead to depression and eating disorders, as well as stress for their families and peers.

Elizabeth Weil wrote about this phenomenon last week in The New York Times Magazine:

"Now most researchers seem to agree on one thing: Breast budding in girls is starting earlier. The debate has shifted to what this means. Puberty, in girls, involves three events: the growth of breasts, the growth of pubic hair and a first period. Typically the changes unfold in that order, and the proc¬ess takes about two years. But the data show a confounding pattern. While studies have shown that the average age of breast budding has fallen significantly since the 1970s, the average age of first period, or menarche, has remained fairly constant, dropping to only 12.5 from 12.8 years. Why would puberty be starting earlier yet ending more or less at the same time?"

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Louise Greenspan, a pediatric endocrinologist and co-author of the Pediatrics paper, will join The Daily Circuit Monday to discuss the issue.

"We used to say that eight was an easy cut off to say, yes, we know this is normal, this is the right age," she said.

Greenspan said her study showed that healthy, normal girls were developing earlier then ever before.

"I'd love to have a day where puberty is separate from sexuality," she said. "Why can't we just link the term puberty with growing taller or needing new shoes?"

Julia Graber, professor and associate chairwoman of psychology at the University of Florida, will also join the discussion.

KERRI'S TAKEAWAY

Although there are still a lot of questions about the causes of early puberty, obesity is definitely a factor.