Medical problems include increased chance of breast cancer
By DORSEY GRIFFITH – McClatchy Newspapers
SACRAMENTO, Calif. — 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.
It’s a “superb” review of all the factors involved, said Dr. Marion Kavanaugh-Lynch, an oncologist and director of the California Breast Cancer Research Program in Oakland.
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.”
Kavanaugh-Lynch said most breast cancer cells thrive on estrogen, and girls who menstruate early are exposed to more estrogen than girls maturing normally.
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 accidental exposures of girls to chemicals.
Steingraber concludes that early puberty could best be understood as an “ecological disorder,” resulting from a variety of environmental hits.
She also reports on links between early puberty and social and emotional problems.
THIRD-GRADERS NEEDING TAMPONS
Steingraber’s report is being released amid growing national interest in how the environment contributes to disease.
For years, parents, doctors and teachers have recognized the trend in early puberty among girls, with little information to explain it.
Dr. Charles Wibbelsman, a pediatrician with Kaiser Permanente in San Francisco, said he now routinely sees girls as young as 8 with breast development and girls as young as 9 who have started their periods. He said the phenomenon is most striking in African-American girls.
“We don’t think of third-graders as using tampons or wearing bras,” he said. In fact, he said, pediatricians are having to adjust the way they do regular checkups.
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 since the mid 20th century, she said, other factors seem to have “hijacked the system” that dictates the onset of puberty.
Rising childhood obesity rates clearly play a role, she said, noting that chubbier girls tend to reach puberty earlier than thinner girls. Levels of leptin, a hormone produced by body fat, is one trigger for puberty, and leptin levels are higher in blacks than in other groups.
But obesity cannot alone be blamed for the shifts, she said. Steingraber’s paper explored many other factors that likely play a role, including exposure to common household chemicals.
“My job was to put together a huge jigsaw puzzle,” with each study a piece of it, she said.
“The world is not a good place for early maturing girls,” she said. “They are at higher risk of depression, early alcohol abuse, substance abuse, early first sexual encounter and unintended pregnancies.”