March 29, 2024
BANGOR DAILY NEWS (BANGOR, MAINE

Study finds U.S. girls reaching puberty sooner> Cause may be environmental

CHICAGO — American girls reach puberty earlier than commonly believed, with nearly half of black girls and 15 percent of white ones beginning to develop sexually by age 8, a study indicates.

The study raises troubling questions about whether environmental estrogens, chemicals that mimic the female hormone estrogen, are bringing on puberty at an earlier age.

It also suggests that sex education should begin sooner than it often does, researchers said.

“I don’t think parents, teachers or society in general have been really thinking of children that young — second- and third-graders — having to deal with puberty,” said the study’s lead author, Marcia E. Herman-Giddens of the University of North Carolina at Chapel Hill.

The research is in the April issue of the journal Pediatrics, published by the American Academy of Pediatrics.

Environmental estrogens occur from the breakdown of chemicals in products ranging from pesticides to plastic wrap. Real estrogen is used in some hair products, including pomades primarily marketed to blacks, said Herman-Giddens, an adjunct professor of maternal and child health.

She said research is needed to know whether real estrogen in products and environmental estrogen can affect sexual development.

The study involved 17,000 girls ages 3 through 12. They were seen in 65 pediatric practices around the country. About 1,600 of the girls, or 9.6 percent, were black.

At age 8, 48.3 percent of black girls and 14.7 percent of white girls had begun developing breasts, pubic hair or both. Menstruation occurred at 12.16 years in blacks on average and at 12.88 years in whites.

The average age of menstruation for white girls has been unchanged for 45 years, Herman-Giddens said.

For black girls, the average is about four months younger than it was 30 years ago, when poor nutrition and poverty, which can delay puberty, afflicted more blacks, she said. “I think we may be seeing a catch-up,” Herman-Giddens said.

She acknowledged that her findings may have been skewed if a significant number of the girls were brought to their doctors because of concerns that they were developing too early sexually.

The study, and other research, suggests that blacks and whites have some inherent differences in sexual development.

Herman-Giddens said the findings also suggest that some girls who have been diagnosed with early puberty, and perhaps given drugs to delay it, may be developing normally.

She said medical textbooks typically suggest the age of sexual development is much later, based on decades-old statistics from England taken from a relatively small number of white girls who were mostly in foster care.

An expert not involved in the study called the work very important but said it will probably not change doctors’ practices.

“We’ve always known that there was a range of development,” said Dr. Marianne Felice, chief of adolescent medicine at the University of Maryland.

“It may vary by race, it may vary by nutritional status and it may also vary by … how old the mothers were or how old the older sisters were when they hit the same landmarks in sexual characteristics.”


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