Quinn on Nutrition: Keeping a lid on BPA’s

July 18, 2016

BPA, UV, polycarbonate. Yikes. Do we need a chemistry degree to figure out what to eat and drink? Perhaps we do. After all, the science of nutrition is about the chemistry of food in our bodies … and how those chemical reactions affect our health.

Here’s one example to pay attention to as we guzzle bottled water on these hot summer days. Bisphenol A (BPA) is a chemical used to make some plastic food and beverage containers. BPA from these containers can migrate into the food they embrace — especially if the food or beverage is hot.

Studies on animals exposed to BPA have found that, in high doses, it can affect the function of certain hormones in the body, including those that affect reproduction.

At low levels of exposure, however, BPA is safe, according to an ongoing review of scientific evidence by the USDA Food and Drug Administration (FDA). So how do we keep our exposure to BPA at a minimum?

Avoid BPA-containing plastics. On the bottom of plastic food and beverage containers, you’ll find a resin code encased in a triangle. (See picture). A resin code 7 indicates that the container may be made of a BPA-containing plastic, says the FDA.

Keep it cool. According to the National Institutes of Health (NIH) Toxicology Program, the degree to which BPA leaches into food depends a lot on the temperature of the food or the container. Never microwave foods in plastic containers, including margarine tubs and restaurant carryout containers, advises registered dietitian Jackie Newgent, spokesperson for the Academy of Nutrition and Dietetics (AND). And don’t reuse plastic containers from microwavable meals. "They are safely designed for one-time-use only," says Newgent.

Use glass containers more often. They are safer bets to store and reheat hot foods.

Keep bottled water out of the sun. Ultra-violet (UV) rays can increase the amount of undesirable compounds, including BPA, that leach into bottled water, say food chemists.

And here’s an interesting side note: Studies on animals suggest that high amounts of BPA may harm the ability to reproduce. In humans, one recent study on women undergoing fertility treatments found that soy foods may play a role in protecting against the negative effects of BPA. In this study (March 2016 Journal of Clinical Endocrinology and Metabolism), women whose diets included soy foods had better birth rates — even with increasing levels of BPA in their blood — than women who did not eat soy products. More research is needed, of course.

"Additional research is underway to enhance our understanding of BPA," says the FDA. "We reassure consumers that current approved uses of BPA in food containers and packaging are safe."




McClatchy-Tribune Information Services