Reaching Puberty Early: Environmental Factors Are Putting Black Girls at Risk

Article excerpt

JUST AFTER MY DAUGHTER TURNED 7, she came to me and nervously announced that she had bumps on her chest. I felt beneath her nipples, and, indeed, there were prominent, hard lumps. A friend had gone through this with her 7-year-old, so my first fleeting panic about cancer was replaced by the alarming realization that my little girl was developing breasts. I made an appointment with our family doctor, but it was two weeks off.


In the meantime, I googled "premature puberty" and discovered the literature on environmental causes of early puberty. I also found that family history, prenatal and early postnatal exposures were key. I had adopted my daughter when she was 3 months old. While I knew she'd never been breastfed, I knew little else about her history or that of her birthmother. I set out to find out everything I could about early puberty in girls, trolling through the medical literature, gleaning library shelves, exploring the websites of environmental organizations and conversing with scientists who are grappling with this issue.


Why was I so alarmed about my Black daughter starting puberty at the age of 7? As a white mom who first menstruated at 13, I was afraid of the prospect of my child dealing with sexuality at such a young age. My fear increased as I found studies showing a litany of social risks for girls who mature early: poor self-esteem, increased depression, early sexual intercourse and increased drug and alcohol use and abuse. Most worrisome to me were the increased health risks associated with early puberty: breast cancer, type II diabetes, cardiovascular disease and polycystic ovarian syndrome. Early-maturing girls reach their adult height early, and if this occurs by age 12, they have a significant risk of getting a very aggressive form of breast cancer. I knew that I had to take action.

One of the first discoveries I made was that girls were having different experiences with puberty based on race. A 1997 study, conducted at pediatricians' offices nationwide, found that girls were showing the first signs of puberty about a year earlier than was considered normal. Most striking was that Black girls were beginning puberty about a year earlier than white girls. Compared with 8-year-old white girls, about four times as many Black 8-year-oids grow pubic hair and develop breast buds. The age when girls get their first periods has also dropped (though less dramatically) over the past 30 years, and Black girls precede white girls by half a year in this regard.

Dr. Paul Kaplowitz of the Children's National Medical Center in Washington, D.C., has suggested that genetic differences between Black and white people may explain early puberty in Black girls. He wonders if the genes involved in insulin resistance, which occurs more often in Black people, may predispose Black girls to earlier puberty by affecting their hormone levels. However, in 1944, girls of both races started puberty at the same age. Today, girls from well-off Black families in South Africa and Cameroon get their first periods at least one year later than Black girls in the United States, and Kenyan Black girls menstruate four years later, on average, than Black girls here.

Doctors have suggested that the dramatic rise in childhood obesity has contributed to earlier puberty. We know that being fat increases the estrogen in a girl's body, and estrogen is the chief trigger for breast budding. At every age, the percentage of Black girls who are overweight is significantly higher than that of white girls. However, researchers have concluded that, while obesity plays a role, it is not the only cause of early puberty. My daughter, for example, is very thin, so obesity wasn't even a possible culprit in her case.

When I began looking into environmental causes, however, a clearer picture began forming. Dr. Sandra Steingraber, author of the Breast Cancer Fund's comprehensive 2007 report "The Falling Age of Puberty in U. …