12:32 am August 12, 2010, by Theresa Walsh Giarrusso
A new study finds that girls are more likely to start developing breasts by age 7 or 8 today as opposed to a later age in the past, according to the journal Pediatrics.
Being overweight seemed to influence the early breast development. But researchers are also concerned about environmental causes for the earlier development.
“Our analysis shows clearly that the white participants entered puberty earlier than we anticipated,” said Dr. Frank M. Biro, the first author of the study and the director of adolescent medicine at Cincinnati Children’s Hospital Medical Center.
Overweight girls were more likely to have more breast development, the study showed. But Dr. Biro said he did not think weight was the whole story. He said it was possible that environmental chemicals were also playing a role, and added that he and his colleagues were now studying the girls’ hormone levels and lab tests measuring their exposures to various chemicals…”
Dr. Catherine Gordon, a pediatric endocrinologist and specialist in adolescent medicine at Children’s Hospital Boston, said that breast development nor date of first menstruation has changed for white girls of normal weight.
The article went on to say:
“Dozens of studies have been published in the years since. Arguments continue, but many doctors accept the idea that heavier girls often develop earlier. And subsequent studies have also found that black and Hispanic girls mature earlier than whites, even when weight is taken into account. No one knows why. Though breasts may be sprouting earlier, the average age of first menstruation, between 12 and 13, has not really changed.