Higher levels of the chemical BPA found in urine was associated with obesity in children, found a study published online today in Pediatrics.

Researchers from the University of Michigan found a very strong relationship between the amount of Bisphenol A in the urine of children and two strong measures of obesity -- Body Mass Index greater than the 95 percentile for age and having a high waist circumference-to height-ratio. They did not find a link between BPA and any of the other commonly measured negative outcomes of obesity, such as elevated diabetes and pre-diabetes markers, increased cholesterol and other blood fats, or total body fat.

This large study uses data collected between 2003-2010 by the National Health and Nutrition Examination Survey. NHANES is a cross-sectional national study of the U.S. population, which has been collected continuously for the last three decades.

The industrial chemical is used in the manufacturing of many plastics, called polycarbonates, and is also used in the epoxy glues that bind one plastic piece to another. It can be found in baby bottles, the coatings on metal pieces to remove the sharp edges, baby toys, and dental sealants. In adults, increased BPA is connected to higher levels of obesity, type-2 diabetes, and cardiovascular disease. Many manufacturers have voluntarily removed BPA from infant-associated products, and this chemical is banned in the European Union and Canada from being used in baby products.

This well designed study took into account gender, ethnicity, and poverty, and excluded anyone who already had diabetes or was pregnant. On analysis, this study showed a connection between excess excretion of BPA and obesity, but did not correlate to any other illness-predicting factors commonly seen in obesity. The study could not determine if the higher urinary levels of BPA caused obesity. One factor not mentioned in this study is the fact that BPA is strongly fat soluble and, in theory, an overweight person could retain much more BPA in their body than a thin person and thus excrete more in their urine.

Increased blood fats and pre-diabetes often require a decade or more of obesity to be present and, since this study was done using the data from children 6 to 16 years, the reason that elevated excretion of BPA did not correlate to these dangerous health factors may have been simply because the children were not overweight for a long enough period of time for these health risks to develop.

Even still, it's another reason to avoid BPA containing plastic around your child.

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