Friday, July 16, 2010

A Clear and Plastic Danger

A Clear and Plastic Danger: "A Clear and Plastic Danger
By Dr. David Blyweiss on 07/15/2010

I’ve been concerned about the health effects of plastics since I first learned about them back in the 1990s. Since then, research has shown that those handy plastic containers you put your food in contain dubious chemicals like bisphenol A (BPA) and polyvinyl chloride (PVC) that can leach into your food.

A 2008 study in the Journal of the American Medical Association found that people with the highest levels of BPA were twice as likely to suffer from heart disease and diabetes than those with the lowest levels. These substances can disrupt crucial antioxidant and DNA activity in the body, as well as the normal functioning of the endocrine system. But what worries me even more is that, once inside the body, BPA acts like the hormone estrogen. Based on this characteristic, new studies link BPA to reproductive damage in both men and women. It also boosts the risk of developing breast cancer.

Unfortunately, it’s hard to avoid BPA. Along with some food storage containers, you can also find this hormone-disrupting chemical in plastic water bottles and even in the cans that hold many of the foods you eat. The FDA says that this isn’t a threat, but a new Consumer Reports’ test of canned foods (including soups, juice, tuna, and green beans) found that almost all of the 19 name-brand foods tested contain some BPA.

The consumer group reports that a 165-pound adult eating one serving of canned green beans could ingest 80 times more BPA than the recommended upper daily limit. Children eating multiple servings of canned foods daily with BPA levels comparable to the ones they found in some of the tested products could get a dose of BPA approaching levels that have caused adverse effects in several animal studies.

Perhaps most telling is that in Japan major manufacturers voluntarily changed their can linings in 1997 to cut or eliminate the use of BPA because of concerns about health effects. A 2003 Japanese study found that the levels of the chemical in subjects’ urine dropped by 50 percent after the change in cans was made.

But BPA isn’t the only problem. The PVC used in many brands of plastic wrap is also problematic. This type of plastic contains phthlates—plasticizers, which have a similar estrogen-like effect in the human body. And like BPA, PVC has been associated with infertility problems and abnormalities of genital development.

Ideally, you should switch to glass, metal or ceramic containers to store your leftovers. But, I know that’s next to impossible. The next best option is to become well-versed in how to pick your plastics. The best way to tell if a plastic container contains BPA or phthalates is to look at the number on the bottom of the container. Containers marked with a 1, 3, or 7 contain phthalates or BPA, while ones labeled with 2, 4, or 5 are safer.

If plastic storage containers are used, never expose them to heat or use them in the microwave. This can cause even greater leaching. Remove cling wrap from any store-bought meats, cheeses and fish and repackage them in a safer container. It’s also important to throw away any container that is scratched or appears worn since bacteria can hide in these nooks and crannies.

While it’s difficult to completely avoid plastics, minimizing its use can reduce the overall amount of plasticizing chemicals that wind up in your body. And, even though it might seem like a bit more effort when storing your holiday leftovers, opting for safer alternatives to BPA- and PVC-laced containers can give you a big health payoff for years to come.

References:

Baccarelli A. Epigenetics and environmental chemicals. Current Opinions in Pediatrics. 2009;21:243-251.

Concern over canned foods. Consumer Reports. December 2009.

Munguía-López EM. Migration of bisphenol A (BPA) from can coatings into a fatty-food simulant and tuna fish. Food Additives and Contaminants. 2005;22:892-898.

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