Friday, April 1, 2011

Bisphenol A (BPA): What you should know

BPA is one of the most commonly manufactured chemicals in the world. It is a component of polycarbonate plastic and is found in a wide range of common materials and food packaging. It has been known for many years that BPA has estrogenic properties; its effects on the reproductive systems of animals -fish, amphibians and mammals - have raised concern for humans. The chemical has been called an endocrine disrupter, which can mimic the body’s own hormones and lead to negative health effects. Animal studies (those unfortunate mice and rats) have suggested effects of BPA on the brain, breast, prostate, thyroid, obesity, sexual behavior et al. Some studies suggest an increased risk for breast and prostate cancer. Newborns and children may be specially affected by environmental BPA levels, due to their reduced capacity to eliminate the substance and their higher daily exposure, adjusted for weight. A study from Rockefeller University on primates in 2008 showed that even at relatively low exposure levels, BPA abolishes the ability of spinal synapses to respond to estrogen, which may play a critical role in cognition and mood. An English study published in the JAMA (University of Exeter - 2008) showed that higher levels of BPA in the urine of US adults correlated with cardiovascular disease, diabetes and abnormal liver enzyme levels. A study carried out by the Division of Research at Kaiser in Oakland showed that male workers in China with high occupational exposure to BPA had a significantly higher risk of lowered sexual desire, erectile dysfunction and difficulty ejaculating. This study is obviously important to men, and a motivator for youth to avoid exposure as much as possible. I have cited only a few examples of research on BPA that suggest negative health effects on humans and animals. While studies abound, our response in the US has been painfully slow.

Canada announced its intent to ban the import and sale of polycarbonate baby bottles containing BPA in 2008. Walmart announced soon thereafter that it would stop selling food containers, water and baby bottles, sippy cups and pacifiers containing BPA at its Canadian stores. In 2010, Canada declared BPA to be a toxic substance and is proceeding to decrease its use overall. European countries have been slower to act. But the European Union executive commission plans to stop the manufacturing of polycarbonate baby bottles containing BPA by June, 2011. Minnesota, Chicago, Connecticut, Massachusetts and Maine have taken steps to ban products containing BPA from baby food containers and other products. However, in 2009, California’s EPA unanimously voted against placing BPA on the state’s list of chemicals that are believed to cause reproductive harm.

What you can do
1) Shop wisely: BPA is found in the internal coating of food and beverage metal cans to protect the food from the metal. Choose fresh or frozen foods over canned whenever possible. Eden Organic has eliminated the use of BPA in their canned and packaged food, and Muir Glen organic tomato products will be BPA free this year. These products are available at natural food markets.
2) In your kitchen: If you feed your baby from a bottle, use glass, and avoid plastic pacifiers and cups. Don’t microwave food in plastic containers, and store leftovers in glass or ceramic containers. Carry extra water in a stainless steel or glass bottle. Nalgene is now selling plastic water bottles made of copolyester , with non-BPA materials. Hikers will want to have a light-weight water bottle, but more research may be needed on the long term safety of these new materials.
3) Go to the website of healthyfoodaction.org and sign their petition asking President Obama to eliminate the use of potentially cancer-causing chemicals in our environment, including BPA
4) Ask our assemblymember, Jared Huffman, to work on banning BPA containing products in California. Mention the 2009 California EPA vote when you call or write. Huffman is an environmentalist – 479-4920. Contact Governor Jerry Brown while you are at it: 916-445-2841. Go citizens!
Sadja Greenwood MD, MPH back issues on this blog

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