Q & A Library

Since the 1950s the chemical bisphenol A (BPA) has been used in plastics found in food and beverage containers, water bottles, baby bottles, toys and many other consumer products. In a study published in the September, 17 2008 Journal of the American Medical Association found associations between exposure to BPA and cardiovascular disease, type 2 diabetes and liver enzyme abnormalities in adults. This wasn’t the first time BPA has been linked to health problems in humans - the National Toxicology Program has also reported possible effects on brain and prostate development in young children and fetuses. Earlier research in animals showed associations between BPA, diabetes and liver damage.

The FDA has continued to insist that BPA is safe and, as I write this, contemplates no changes in its position. However, some companies are taking matters into their own hands. Wal-Mart is phasing out sales of baby bottles containing BPA in its U.S. stores, and Nalgene is removing BPA from its water bottles.

The study linking BPA to diabetes and cardiovascular disease involved a representative sample of 1,455 U.S. residents. Their BPA exposure was determined on the basis of concentrations of the chemical excreted in urine. The researchers found that those with the highest concentrations had almost three times the risk of cardiovascular disease and 2.4 times the risk of diabetes as those in with the lowest concentrations. This same group displayed abnormal concentrations of three liver enzymes. Even the highest BPA concentrations seen were within current scientific safety limits.

In an editorial accompanying the study, Frederick vom Saal, a biology professor at the University of Missouri, said the findings came as no surprise. He was among 38 experts who reviewed 700 studies of BPA and concluded that it had a high probability of causing harm.

Meanwhile, researchers from the Dartmouth Institute for Health Policy and Clinical Practice noted that measuring BPA levels in only a single urine test and then looking at rates of disease doesn’t tell you which is cause and which effect.

Clearly, we need more and better studies to clarify whether BPA increases health risks in humans. In the meantime, I recommend avoiding plastics containing the chemical. You can substitute those made with polypropylene (#5 PP), high-density polyethylene (#2 HDPE), and low-density polyethylene (#4 LDPE). New BPA free synthetics such as "Tritan" are also coming on the market and appear to be safe. You can also reduce your exposure by buying foods and beverages frozen or packed in glass jars or bottles instead of cans.

Andrew Weil, M.D.