Alyssa Leight is 8 years old. She started showing signs of entering puberty last year.
"She sucked her finger, she slept with a blanket, and she had pubic and underarm hair," says her mother, Kelly Leight.
Alyssa's early passage into puberty is unusual, but less so than in previous generations, says Marcia Herman-Giddens of the University of North Carolina School of Public Health. She has been noticing a number of very young girls at her clinic with clear signs of sexual development.
"I don't believe nature intended, for want of better words, that 8- and 9-year-old children are beginning puberty," says Herman-Giddens.
Herman-Giddens launched a nationwide study of 17,000 girls. The study's goal was to determine if there has been a fundamental change in the age at which girls are entering puberty. The results were surprising. Herman-Giddens found that on average, girls showed the first signs of puberty about 1 year younger than the standard medical textbooks suggested.
"I believe that we are seeing a real change in the onset," she says.
So what's causing this shift? Herman-Giddens says several environmental factors may be to blame:
- The rising obesity rate in children. Kids that are overweight seem to develop faster.
- Hormones in meat and dairy products.
- Exposure to chemicals like PCBs and DDT.
But the study has come under attack. Critics point out that the average age when girls begin to menstruate--about 12 1/2--has not changed in 50 years. A group of pediatricians labeled Herman-Giddens' claims as potentially medically dangerous because doctors who accept a younger age for the onset of puberty as normal might overlook serious medical conditions.
Dr. Maria New, a pediatric endocrinologist with New York Weill Cornell Medical Center, disputes Herman-Giddens' findings.
"I have not observed any increased frequency of early puberty in the children that I seem and we run a clinic two times a week of about 30 children each," says New.
New says that most cases of early puberty she sees are caused by medical conditions like tumors or hormonal imbalances, which, if left untreated, could be dangerous.
Leight's mother was concerned about her daughter's early development, even though her pediatrician was not. She brought her daughter to see New. Her diagnosis? The early puberty was the result of a genetic disease.
"It's not a fatal mistake, but it is a mistake which could cost the child loss of height," says New.
New prescribed medication to keep puberty on hold for a few more years.
"I like being a kid because it's fun," says Alyssa.
Herman-Giddens defends her study, but agrees that accepting early puberty as normal does pose dangers.
"We need to be very careful not t dismiss what we're finding as being normal in the sense of being okay, that it's not anything we need to worry about, because I think we do need to worry about it and it's not okay," she says.
Despite all the criticism she has received, Herman-Giddens says she is planning a new study of early puberty--this time among boys.
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