Girls in the United States are reaching puberty at very early ages, increasing their risk of breast cancer, social problems, and emotional problems.
While the biological signs of female puberty -- menstruation, breast development, and growth of pubic and underarm hair -- typically occurred around 13 years of age or older just decades ago, today girls as young as 8 are increasingly showing these signs.
African-American girls are particularly vulnerable to early puberty.
Aside from the social and emotional implications, early puberty exposes girls to more estrogen, which increases their risk of breast cancer because the disease thrives on estrogen.
According to biologist Sandra Steingraber, the author of the report titled "The Falling Age of Puberty in U.S. Girls: What We Know, What We Need to Know," "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."
"For every year we could delay a girl's first menstrual period,” she says, “we could prevent thousands of breast cancers."
Theories behind what is causing the early-puberty trend abound, but the actual causes are not known. Potential causes noted in the paper include:
- Rising childhood obesity rates and inactivity
- Formula-feeding of infants
- Excessive TV viewing and media use
- Family stress
- Exposure to environmental chemicals
Early puberty is likely an “ecological disorder,” according to Steingraber, that’s being caused by a number of environmental factors.
The Breast Cancer Fund, “The Falling Age of Puberty in U.S. Girls: What We Know, What We Need to Know”
Chicago Tribune September 16, 2007