Why Are So Many Of Our Youngsters Going Through 'Preschool Puberty'?Hormone-mimicking chemicals found in food, water, and many consumer goods may well be the cause of why children as young as eight are showing signs of sexual development.
Kids these days are growing up too fast -- in more ways than one. American girls are reaching puberty up to a year earlier than in previous generations, with some children showing signs of sexual development as young as age 3. In extreme cases, girls are budding breasts before they've even learned to read.
Researchers call this phenomenon "precocious puberty," which some say is on the rise. Forty-eight percent of African-American girls and 15 percent of Caucasian girls show physical signs of puberty by age 8, according to a study of 17,000 U.S. girls published in Pediatrics in 1997. In a subsequent study of more than 2,000 boys, lead author Marcia Herman-Giddens found that 38 percent of African-American boys and 30 percent of Caucasian boys showed signs of sexual development by age 8.
What's going on? Although scientists have yet to prove definitive causes, many suspect that hormone-mimicking chemicals, obesity and stress all contribute to precocious puberty. The chemicals, often called endocrine disruptors, are of particular concern because they're everywhere -- in food, water, personal-care products, some plastics and many consumer goods.
Pediatrician Darshak Sanghavi notes in The New York Times that outbreaks of precocious puberty are most often traced to accidental exposure to drugs in hormone-laden products. He describes a case in which a kindergarten-age boy and his younger sister had both begun growing pubic hair. In addition, the boy was exhibiting aggressive behavior
When Sanghavi's colleagues examined the children, they discovered that both had extremely elevated levels of testosterone -- equivalent to those of an adult male -- and that their father was using a concentrated testosterone skin cream "for cosmetic and sexual purposes." The children had absorbed the testosterone from normal skin contact with their father.
Of course, we can't blame it all on testosterone. Phthalates, ubiquitous industrial plasticizers common in everything from personal-care products to vinyl and plastic packaging, mimic estrogen. So do compounds in some pesticides and flame retardants. A growing body of evidence suggests that these and other endocrine-disrupting chemicals can interfere with sexual development, an idea widely introduced in the groundbreaking book "Our Stolen Future" by Theo Colburn, Diane Dumanoski, and John Peterson Myers.
In the two decades since the book's publication, evidence has mounted that substantiates its main thesis. The September, 2006 issue of Alternative Medicine points out that a number of human studies have found possible links between endocrine disruptors and early puberty. One study found that Puerto Rican girls whose breasts developed earlier were three times more likely to have elevated levels of phthalate esters in their blood.
Some researchers have linked precocious puberty with factors including obesity, stress, and a sedentary lifestyle. "In the animal industry, to hasten puberty, they keep the animals confined, they feed them really rich diets, and they grow really fast," Marcia Herman-Giddens notes in Alternative Medicine. "That is exactly what we are doing to our children."
Parents can take practical steps to minimize their children's risk for early puberty and encourage healthy lifestyles:
- Avoid meat, milk and dairy products containing growth hormones
- Buy organic produce
- Minimize soy, which mimics estrogen
- Choose green household products
- Encourage children to eat well and exercise
- Prevent babies from chewing on plastic toys
- Avoid polyvinyl chloride (PVC) products, including vinyl shower curtains and toys and packaging that bear the number "3," indicating they're made with PVC.