WASHINGTON (Sept. 19, 4:55 p.m. ET) — Children and teenagers with higher levels of bisphenol A are 2.6 times more likely to be obese than those who have lower levels of BPA, according to an examination of data by the New York University School of Medicine.
But the American Chemistry Council immediately disputed the results, released Sept. 18, arguing that the analysis was “incapable of establishing any meaningful connection between BPA and obesity, due to inherent, fundamental limitations in this study.”
“In particular, the study measures BPA exposure only after obesity has developed, which provides no information on what caused obesity to develop,” said Steven Hentges, director of the Polycarbonate/BPA Global Group of Washington-based ACC.
“The authors themselves state: ‘Obesity develops over time, and causation cannot be inferred from a cross-sectional association of urinary BPA concentration,' ” said Hentges, quoting the report. “The authors further state that their work is ‘at best hypothesis-generating,' indicating that this study is speculative and might, at most, be the basis for conducting additional studies.”
The NYU study team looked at data collected in 2003 and 2004 as part of the National Health and Nutrition Examination Survey and measured body mass and urinary BPA — which is an indirect way of measuring BPA exposure — in more than 2,800 American children and teens.
“Clearly bad diet and lack of exercise are the leading contributors to childhood obesity, but this study suggests a significant role for environmental, particularly chemical, factors in that epidemic,” said lead author Leonard Trasande, an associate professor of pediatrics and environmental medicine at School of Medicine.
“Our study can't identify obesity as being caused by BPA,” said Trasande in the report, which was published in the Journal of the American Medical Association. “But in the context of increasing evidence from experimental studies, it raises further concern, and adds weight to calls for a broader ban on BPA in food packaging.”
However, Hentges disagreed.
“More relevant to actual, real-world safety is the recent, robust [Pacific Northwest] research funded by the Environmental Protection Agency ... that indicates because of the way BPA is processed in the body, it is very unlikely that BPA could cause health effects at any realistic exposure level,” said Hentges.
“Attempts to link our national obesity problem to minute exposures to chemicals found in common, everyday products are a distraction from the real efforts under way to address this important national health issue,” he said.
Eleven states, the city of Chicago and four counties have banned the use of BPA in polycarbonate baby bottles and sippy cups, even though all major baby bottle manufacturers that make products for the U.S. market agreed in 2009 not to make or sell baby bottles or sippy cups that contain BPA.
In addition to the bans in the United States, BPA is banned in baby bottles in the European Union, Canada and China.
In July, the FDA — in response to an industry petition — agreed to exclude baby bottles and sippy cups from regulations that permit companies to use BPA in food-contact applications.
“Although governments around the world continue to support the safety of BPA in food-contact materials, confusion about whether BPA is used in baby bottles and sippy cups had become an unnecessary distraction to consumers, legislators and state regulators,” said Hentges after FDA issued its decision this past July. “[This] provides certainty that BPA is not used to make the baby bottles and sippy cups on store shelves, either today or in the future.”
BPA is used to make PC and epoxy resins. The materials are used to line metal cans and are found in thermal printer paper and some dental composites and sealants.
An international panel from the World Health Organization said in November 2010 that it “would be premature” to initiate any measures to manage potential risks to public health from BPA.
“Levels of BPA in the human body … are very low, indicating that BPA is not accumulated in the body and is rapidly eliminated through urine,” said WHO.
Those conclusions were reached by WHO just nine days after a peer-reviewed study published online in the scientific journal Environmental Science and Technology said BPA levels found in canned food — as well as fresh foods wrapped in plastic packaging in the U.S. — are nearly 1,000 times lower than the “tolerable daily intake levels” set by the EPA and the European Food Safety Authority.
It is estimated that more than 8 billion pounds of BPA are produced worldwide every year.