The dispute over the dangers posed by bisphenol A (BPA), a chemical found in common plastics, has taken a new turn. Two US government bodies have previously issued conflicting advice about its safety, but now an epidemiological study suggests it raises the risk of heart disease and type 2 diabetes. More than 2M/tonnes BPA are produced worldwide each year. The chemical is found in the plastic lining of food and drink cans and in plastic baby bottles. Over 93% of Americans have traces of it in their urine. David Melzer at the Peninsular Medical School in Exeter, and colleagues have analysed data from 1455 American adults who took part in a national survey in 2003-4. Overall, 79 volunteers had heart disease and 136 had type 2 diabetes - both diseases were more common among those with high BPA concentrations. After adjusting for age and sex, the quarter of subjects with the highest concentration of BPA were almost three times as likely to have cardiovascular disease and more than twice as likely to have diabetes as those in the lowest quartile (J Am Med Assoc, vol 300, p1303). Nira Ben-Jonathan of the University of Cincinnati, Ohio, said the findings complement her own research. She found that BPA, when applied to human fat tissue at levels found in the environment, suppresses adiponectin, a hormone that regulates insulin sensitivity, which could explain how BPA might predispose someone to diabetes.
