By Barbara Kessler
Green Right Now
You are what you eat. But according to a new study, you also are what your food was wrapped or packed in, at least to a degree.
And if that food was enclosed in plastic or plastic resin-lined cans, it could be having an effect on your health.
Researchers investigating whether the endocrine-disrupting plastic chemicals BPA (bisphenol A) and DEHP migrate from food packaging into humans have found evidence that they do.
The study, by researchers from the Silent Spring Institute, the Breast Cancer Fund and Vassar College, sampled the urine of 20 participants in 2010, testing the levels of BPA and DEHP while the study subjects ate a regular diet containing canned and packaged foods, and then again when the study group was placed onÂ a fresh food diet.
They found that the levels of BPA and DEHP dropped dramatically when the participants switched to a fresh food, unpackaged diet. The steep decline in the levels of excreted BPA and DEHP suggesting that these chemicals, which are routinely found in measurable levels in the their bodies of 90 percent of Americans, had been ingested via the plastic food packaging.
Plastic frozen food trays and the resin liners of food cans have been shown in previous studies to contain BPA. But it was unknown how much of the chemical leached into the food. BPA in hard plastic formulated a polycarbonate (a hard, clear plastic used in bottles and eyeglass lenses) has been found to leach into liquids when the containers or the liquids are heated. Studies showing that BPA was getting into formula or other liquids in polycarbonate baby bottles prompted several governments to either ban BPA-containing plastic for such uses or launch studies into the effects of BPA.
Studies with rodents have implicated both BPA and DEHP as edocrine disruptors. Studies have shown that they can damage the male hormonal system, especially in developing boys, possibly leading to a reduction in fertility. BPA also has been linked to breast cancer.
Phthalates, the family of plasticizers to which DEHP belongs, also are found widely in plastic food packaging, and have been shown to affect the endocrine system, reduce sperm counts and cause testicular problems in boys. The U.S. Congress banned the use in toys of several varieties of phthalates to prevent babies and toddlers from exposure through chewing on the stretchy plastic toys that had typically contained phthalates. The Environmental Working Group also warns about phthalates in cosmetics, especially in nail polishes and perfumes, in which phthalates are used as hardners or preservatives, respectively.
When the sample group members in the 2010 study switched to a fresh food diet that contained no packaging, their urine levels of BPA and DEHP metabolites “decreased significantly,” according to the study, which appears this week in Environmental Health Perspectives.
The study participants came from five families in the Bay Area. Researchers tested their urine over several days with a three-day “fresh foods intervention” in the middle of regular eating periods. That allowed the team to chart the rise and decline of the chemicals.
The “intervention” reduced the mean concentrations of BPA by 66 percent and the DEHP metabolites by 53-56 percent.
The families chosen for the study had daily exposures to dietary sources of BPA and phthalates via personal water bottles, large polycarbonate 2-5 gallon water bottles in office coolers, meals microwaved in plastic and foods eaten in restaurants.
Previous studies have found that people drinking from polycarbonate bottles registered an increase in BPA levels and people placed on a vegetarian Buddhist “temple stay” showed reduced excretion of phthalates and antibiotics.
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