Black Children Are Increasingly Obese To Chemicals

Research published today shows that black children who have high levels hormone-altering chemicals in their shampoos or lotions are more likely than white kids to become obese.

The study by New York University scientists is the second to link phthalates to obesity in children but the first to use a large sample of children and look for racial disparities.

Black children experience higher levels of chemicals than their peers of other races. According to data collected from 2884 children between 6 and 19, they are 22 percent more likely be obese for each triplet of these compounds. Hispanic and white children did not have any links to obesity.

Leonardo Trasande from New York University School of Medicine, the principal author of the study said that "the takeaway is that we must consider environmental exposures in looking at the obesity issue." The effects of environmental chemicals can be independent from exercise and diet.

Phthalates are a large family of chemicals with varied uses. The phthalates associated with black children's obesity were the kind commonly added to personal care products to make fragrances last longer. Other phthalates are used to make vinyl and can be found in food packaging, medical devices and flooring.

Trasande and colleagues checked for a variety of phthalates and only found a link to the kinds used in personal care products.

Both Trasande and other researchers were quick to point out that this doesn't mean phthalates cause obesity.

Joe Braun from Brown University, who is an epidemiology professor, said that the study was large and representative of all areas. He wasn't involved in any research. "But since they measure phthalates levels in urine and obesity at the same time, it's a chicken and egg problem. Do phthalates cause obesity or are obese children more exposed?" It's unclear, he said, when they were exposed relative to when they became obese.

Kathryn St. John is a senior director for product communications at The American Chemistry Council. She represents chemical producers.

St. John said that "Attempts at linking our national obesity problem with minute exposures chemicals found in common everyday products are an obstacle to efforts to address this serious national health issue."

Previous studies have linked phthalates to hormone disruption - including hormones responsible for fat tissue and development of the brain and reproductive system. Trasande said it's plausible - though not proven by this study - that phthalates could contribute to obesity by messing with receptors that metabolize lipids and carbohydrates.

One previous study linked phthalates to obesity in children. In New York City, children between the ages of 6 and 8 years old and Hispanic or black phthalates had a higher body mass and larger waists. Phthalates also were linked to adult obesity in a 2007 study.

It isn't clear why the link was found in the study. However, this could have been due to the higher chemical concentrations. For the personal care product-type phthalates, black children had levels 81 percent higher than white children, 45 percent higher than Mexican American children and 4 percent higher than other Hispanic children.

According to the online study published in Environmental Health Perspectives, "One possibility is the different use of phthalate-containing shampoos or lotions by different racial/ethnic group, or products that contain different [phthalate] mixtures."

The researchers didn't find any age-related differences. And, while the black children had higher levels of phthalates as a whole, the association with obesity happened at relatively low levels of exposure, Trasande said. This study was based on data from U.S. Centers for Disease Control and Prevention's nationwide 2008 testing for chemicals in the bodies of people.

Emily Barrett from the University of Rochester, who studies environmental chemical exposure, suggested that it's possible that children of color are more likely to be exposed.

Jennifer Adibi from the University of California San Francisco, an epidemiology professor, stated that many factors, including diet and stress, could affect how children react to chemicals.

In a study released late last year by Trasande and colleagues, another hormone disrupting chemical - bisphenol A - was linked to obesity in only white children.

Trasande had to control for diet, TV watching, gender, and age during the phthalate experiment. He said that although it is difficult to pin chemicals on weight gain, the study requires new ways of thinking.

To determine whether phthalate use is contributing to obesity in children, the next research step will be to study phthalate exposures throughout childhood and fetus.

Adibi stated that the findings were "interesting" and "scary". She hopes they will change the way we think about the risks facing disadvantaged communities.

Adibi explained, "This is another reason for increasing awareness among low-income African American and Hispanic communities and let them be aware that they're at greater risk of chemical exposure and that there are these associations (with obese)."