WASHINGTON — A study published in the Journal of the American Medical Association on Sept. 16 indicated higher levels of bisphenol A (B.P.A.) in adults were associated with increased diagnoses of cardiovascular disease and diabetes. The study’s release coincided with the convening of a Food and Drug Administration panel of experts charged with reviewing the F.D.A.’s Aug. 15 draft assessment on B.P.A. that indicated people are exposed to very low levels of B.P.A. and "an adequate margin of safety exists for B.P.A. at current levels of exposure from food contact uses."
B.P.A. is used in the manufacture of hardened plastics and a range of consumer goods, including the lining of metal cans, some baby bottles and sippy cups, and reusable food and drink containers such as reusable sports water bottles and Tupperware. Concerns over potential adverse health effects of B.P.A. arose in recent years in the wake of studies on animals suggesting the chemical may result in reproductive and hormone-related problems.
A panel of experts from outside the F.D.A. will consider the agency’s draft assessment and related studies and analyses, including a Sept. 3 report by the National Toxicology Program (see Food Business News of Sept. 16, Page 1) and presumably also the JAMA study. The advisory panel was expected to submit its recommendations to the F.D.A. in late October.
The N.T.P., which operates under the Department of Health and Human Services’ National Institutes of Health, in its report indicated "some concern" for B.P.A.’s possible effects on development of the prostate gland and brain, and for behavioral effects in fetuses, infants and children. The N.T.P. said its concerns about other possible health effects of B.P.A. were "minimal" or "negligible." The N.T.P. findings specifying "some concern" provided fuel to both those asserting the safety of B.P.A. and those suggesting it was unsafe even at levels well below the 50 micrograms/kg per day reference dose recommended by the F.D.A. and the Environmental Protection Agency.
The study prepared by United Kingdom and Iowa scientists for JAMA was based on measuring the levels of B.P.A. in urine from 1,455 American adults who participated in the U.S. National Health and Nutrition Examination Survey in 2003-04 and relating those levels to incidence of several health problems. The researchers indicated they found higher B.P.A. concentrations in urine were associated with diagnoses of cardiovascular disease and diabetes. They also found associations between higher B.P.A. concentrations and clinically abnormal concentrations of three liver enzymes examined. The authors indicated they observed no associations with other common health conditions such as cancer.
The authors cautioned their approach in their research, while justified by its being the first large-scale study on B.P.A. effects on a human population, may have resulted in false positive associations and "independent replication is now needed to confirm the associations reported."
Future studies would aim to demonstrate whether or not the association of higher B.P.A. levels with diagnoses of cardiovascular disease and diabetes was causal, and if so, whether the higher B.P.A. levels caused the increased number of diagnoses, or the existence of cardiovascular disease and diabetes resulted in higher concentrations of B.P.A. detectable in urine.
In an editorial accompanying the JAMA article, Dr. Frederick S. vom Saal of the University of Missouri, Columbia, and Dr. John Peterson of Environmental Health Sciences, Charlottesville, Va., both advocates of reducing exposure to B.P.A., said the JAMA study "should stimulate further studies and reevaluation of the basic assumptions in chemical risk assessments that led to F.D.A. assurances B.P.A. is safe."
Dr. vom Saal and Dr. Peterson added, "The good news is that government action to reduce exposures may offer an effective intervention for improving health and reducing the burden of some of the most consequential human health problems. Thus, while awaiting confirmation of the findings of Lang et al (the JAMA study), decreasing exposure to B.P.A. and developing alternatives to its use are the logical next steps to minimize risk to public health."
Dr. Laura Tarantino, director of the F.D.A. office of food additive safety, said, "Right now, our tentative conclusion is that it’s (B.P.A.) safe, so we’re not recommending any change in habits." At the same time, Dr. Tarantino said concerned consumers may reduce their exposure to B.P.A. by avoiding plastic containers imprinted with the number "7," as many of those containers contain B.P.A. Also, Dr. Tarantino said, consumers may avoid warming food in such containers, as heat helps release the chemical.
Dr. Tarantino said the F.D.A. recognized the need to resolve questions raised by various studies but pointed out the research on mice and rats it relied on in making its assessment were more thorough than the recent human research that has raised concerns.
This article can also be found in the digital edition of Food Business News, September 30, 2008, starting on Page 24. Click