Early Puberty in Girls Raising Health Risks (Chicago Tribune)

Chicago Tribune

 

Early-onset puberty raising health risks for girls

By Dorsey Griffith | McClatchy/Tribune newspapers

 

September 16, 2007

SACRAMENTO - American girls are entering puberty at earlier ages, putting them at far greater risk for breast cancer later in life and for all sorts of social and emotional problems well before they reach adulthood .

Girls as young as 8 increasingly are starting to menstruate, develop breasts and grow pubic and underarm hair -- biological milestones that only decades ago typically occurred at 13 or older. African-American girls are especially prone to early puberty.

Theories abound as to what is driving the trend, but the exact cause, or causes, are not known. A new report, commissioned by the San Francisco-based Breast Cancer Fund, has gathered heretofore disparate pieces of evidence to help explain the phenomenon -- and spur efforts to help prevent it.

The stakes are high: "The data indicates that if you get your first period before age 12, your risk of breast cancer is 50 percent higher than if you get it at age 16," said the report's author, biologist Sandra Steingraber, herself a cancer survivor. "For every year we could delay a girl's first menstrual period, we could prevent thousands of breast cancers."

Dr. Marion Kavanaugh-Lynch, an Oakland oncologist, said most breast cancer cells thrive on estrogen, and girls who menstruate early are exposed to more estrogen.

Steingraber's paper, "The Falling Age of Puberty in U.S. Girls: What We Know, What We Need to Know," examines everything from obesity and inactivity to family stress, media imagery and exposures of girls to chemicals that can change the timing of sexual maturation .

Steingraber concludes that early puberty could best be understood as an "ecological disorder," resulting from a variety of environmental hits.

"The evidence suggests that children's hormonal systems are being altered by various stimuli, and that early puberty is the coincidental, non-adaptive outcome," she writes.

Steingraber's report is being released amid growing national interest in how the environment contributes to disease, particularly cancer.

For years, parents, doctors and teachers have recognized the trend in early puberty among girls, with little information to explain it.

Steingraber acknowledges that some of the shift in girls' puberty is evolutionary, a reflection of better infectious-disease control and improved nutrition, conditions that allow mammals to reproduce.

But rising childhood obesity rates clearly play a role, she said, and so may formula feeding of infants and excessive TV viewing and media use.

Copyright © 2007, Chicago Tribune