Over the past three years, Tracee Sioux has taken her daughter to see several doctors to find out why Ainsley began growing pubic hair at age 6. The blood tests and bone-age X-rays turned up nothing unusual. “The doctors always come back with these blank looks on their faces, and then they start redefining what normal is,” Tracee said. “And I always just sit there thinking, What are you talking about, normal? Who gets pubic hair in first grade?”
Jumping the gun
In the late 1980s, Marcia Herman-Giddens, then a physician’s associate in the pediatric department of the Duke University Medical Center, started noticing that an awful lot of 8 and 9-year-olds in her clinic had sprouted pubic hair and breasts. The medical wisdom, based on a landmark 1960 study of institutionalised British children, was that puberty began, on average, for girls at age 11. So Herman-Giddens started collecting data, eventually leading to a study that sampled 17,000 girls, finding that among white girls, the average age of breast budding was 9.96. Among black girls, it was 8.87. When Herman-Giddens published these numbers, in 1997 in Pediatrics, she set off a social and endocrinological firestorm. “I had no idea it would be so huge,” said Herman-Giddens. Along with medical professionals, mothers, worried about their daughters, flocked to Herman-Giddens’s slide shows, gasping as she flashed images of possible culprits: obesity, processed foods, plastics. Then in August 2010, the conflict seemed to resolve. Researchers at three big institutions — Cincinnati Children’s Hospital, Kaiser Permanente of Northern California and Mount Sinai School of Medicine in New York — published another study in Pediatrics, finding that by age 7, 10% of white girls, 23% of black girls, 15% of Hispanic girls and 2% of Asian girls had started developing breasts.
What’s your problem?
So why are so many girls with no medical disorder growing breasts early? Doctors don’t know exactly why, but they have identified several contributing factors. Girls who are overweight are more likely to enter puberty early than thinner girls, and the ties between obesity and puberty start at a very young age. As Robert Lustig, a professor of clinical pediatrics at the University of California, San Francisco’s Benioff Children’s Hospital, explains, fatter girls have higher levels of the hormone leptin, which can lead to early puberty, which leads to higher estrogen levels, which leads to greater insulin resistance, causing girls to have yet more fat tissue, more leptin and more estrogen, the cycle feeding on itself, until their bodies physically mature. In addition, exposure to some environmental chemicals can cause bodies to mature early. Of particular concern are endocrine-disrupters, like “xeno-estrogens” or estrogen mimics. These compounds behave like steroid hormones and can alter puberty timing.
The social connection
Family stress can disrupt puberty timing as well. Girls who from an early age grow up in homes without their biological fathers are twice as likely to go into puberty younger as girls who grow up with both parents. Some studies show that the presence of a stepfather in the house also correlates with early puberty. Evidence links maternal depression with developing early breasts. Children adopted from poorer countries who have experienced significant early-childhood stress are also at greater risk for early puberty once they’re ensconced in Western families. Even evolutionary psychology offers a theory: A stressful childhood inclines a body toward early reproduction; if life is hard, best to mature young. But such theories are tough to prove. Early puberty increases the risk for social problems as well. Girls who develop ahead of their peers tend to have lower self-esteem, more depression and more eating and drinking disorders. Some of this may stem from the same social stresses that contribute to early puberty in the first place, and some of it may stem from other factors, including the common nightmare of adolescence: being different.
Being there for her
So what are families of early bloomers to do? Doctors urge parents to focus on their daughters’ emotional and physical health rather than on stopping or slowing development. In this way, the concept of a new normal is not just a brushoff but an encouragement to support a girl who is vulnerable. “I know they can’t change the fact that their daughter started developing early, but they can change what happens downstream,” said Louise Greenspan, the paediatric endocrinologist at Kaiser Permanente. Parents can keep their daughters active and at healthy body weights. They can treat them the age they are, not the age they look. Early breast growth may be just that — early breast growth: disconcerting, poorly understood, but not a guarantee of our worst fears. “You don’t go directly from the first signs of early puberty to anorexia, depression, drinking and early sexual debut.” Patience and perspective are the greatest palliatives. “The thing with puberty is that everybody is going to go through it at some point,” said a mother. “By another two or three years down the road, all the other girls will have caught up.”
The New York Times