TUESDAY, Dec. 15 (HealthDay News) -- Common chemicals found in plastic toys and elsewhere could contribute to the abnormal growth of breasts in boys, preliminary research suggests.
The research, published in a prominent medical journal for pediatricians, adds fuel to the debate over these chemicals, called phthalates, whose safety has been questioned by some scientists. The chemical industry claims the ubiquitous manmade chemicals, which are used to soften plastics and stabilize fragrances, are safe.
The small study only involved a few dozen boys, but if more research confirms that the chemicals boost estrogen levels, as some scientists suspect, then "we need to start thinking about how we can approach chemical policy and chemical regulation so we don't have phthalates causing this effect," said Dr. Sheela Sathyanarayana, an assistant professor of pediatrics at the University of Washington, who is familiar with the study findings.
Phthalates are found in everyday products, including baby toys, plastic wrap, electronics and shower curtains, and in personal care products, such as perfume and shampoo. They're also found in food, since much of what people eat is exposed to plastics.
Some research has linked phthalates to disrupted hormone levels. Most recently, a small study suggested that exposure to phthalates in the womb might make boys more likely to play with toys typically associated with girls, although there were caveats to that research, and a spokesman for the American Chemistry Council dismissed the findings at the time.
In the new study, Turkish researchers tested 40 boys who were newly diagnosed with gynecomastia -- enlarged breasts -- and 21 boys who didn't have the condition. The researchers checked the levels of phthalates-related substances in their blood.
The levels were 2.8 to 25 times higher in the boys with enlarged breasts, said the researchers, who published their findings in the January issue of the journal Pediatrics.
The study does not prove that phthalate exposure leads to enlarged breasts or raises the risk that gynecomastia will occur. And researchers aren't sure why enlarged breasts develop in boys, said study co-author Dr. Elif Ozmert of Hacettepe University in Ankara, Turkey. According to the study, up to 65 percent of teenage boys can have enlarged breasts.
The condition does appear to have something do with estrogen and testosterone, Ozmert said. It could be "an increase in one, decrease in the other or a combination."
In a statement, Steve Risotto, a senior director at the American Chemistry Council, dismissed the study, saying it "does not fit with established science." For one thing, he said, the study suggests that an indicator of phthalates in the body may be acting like estrogen, but "a significant amount of laboratory data tells us" that indicators of phthalates don't show "estrogenic activity."
However, if estrogen does increase because of exposure to phthalates, this could affect girls too, possibly leading to early breast development, Ozmert noted. "The effect is not limited to boys, but the consequences are different for boys and girls," the researcher said.
Sathyanarayana said another factor could play a role: Those who had enlarged breasts were more likely to have a family history of the condition.
What to do? Larger trials still need to be conducted to confirm or refute the findings. But for now, parents can decrease their exposure to phthalates, in particular by avoiding plastic products labeled with the No. 3, Sathyanarayana said.
And she added the general note that, "as a society, we need to start thinking about whether we want phthalates in general production or not."
Learn more about gynecomastia from U.S. National Library of Medicine.
SOURCES: Elif Ozmert, M.D., Ph.D., Hacettepe University, Ankara, Turkey; and Sheela Sathyanarayana, M.D., assistant professor of pediatrics, University of Washington, Seattle; Dec. 15, 2009, statement, American Chemistry Council; January 2010 Pediatrics.