The study's findings were released Wednesday by the Breast Cancer Fund and Silent Spring Institute and published in the journal "Environmental Health Perspectives," a monthly publication of the National Institute of Environmental Health Sciences.
To evaluate the contribution of food packaging to exposure, researchers measured urinary BPA and phthalate metabolites before, during and after a "fresh foods" dietary intervention.
They selected 20 participants in five San Francisco Bay Area families based on self-reported use of canned and packaged foods. Participants ate their usual diet, followed by three days of fresh foods that were not canned or packaged in plastic, and then returned to their usual diet.
Canned foods in a kitchen cupboard (Photo by Katey Allen)
The researchers collected evening urine samples over eight days in January 2010 and categorized them as pre-intervention, intervention, or post-intervention samples.
Test results showed an average drop of 60 percent in BPA levels when study participants ate a diet that avoided contact with food packaging containing BPA, which is used to make polycarbonate plastics and in the lining of food cans.
Tests showed a 50 percent average drop in DEHP, a phthalate commonly added to some food containers and plastic wraps to increase flexibility.
"Our study provides clear and compelling evidence that food packaging is the major source of exposure to BPA and DEHP," said Ruthann Rudel, lead author of the study and director of research at Silent Spring Institute. "The study shows that a fresh-food diet reduces levels of these chemicals in children and adults by half, after just three days."
BPA and phthalates are both known as endocrine-disrupting chemicals because of their effects on hormone systems.
BPA has been shown to mimic the hormone estrogen, and exposure has been associated with effects on the developing brain, reproductive system, and mammary and prostate glands in laboratory studies.
Phthalates have been demonstrated to interfere with androgen signaling and male reproductive development in laboratory and human studies.
"This is an important study," said Andy Igrejas, director of the nonprofit Safer Chemicals, Healthy Families. "It highlights two things - first, the government still does not have a handle on these chemicals even though health concerns have been established for years."
"Secondly, there is something consumers can do," said Igrejas. "As long as the federal government fails to identify and restrict toxic substances, consumers will increasingly have to take matters into their own hands through efforts like restricting their packaged food."
Organic produce at a San Francisco market (Photo by Demetrios Lyras)
The Toxic Substances Control Act is supposed to ensure the safety of chemicals, but it is widely perceived to have failed. When a chemical is used in food packaging specifically, it is supposed to be regulated by FDA under a separate law.
"This is a compound failure by the government," said Igrejas. "Two agencies are failing to implement two different laws."
"This study suggests that removing BPA from food packaging will remove the number one source of BPA exposure," said Janet Gray, PhD, science advisor to the Breast Cancer Fund and professor at Vassar College. "The study should serve as a call to action for industry and government to get BPA out of food packaging and to fix the broken chemical management system that allows it to be there in the first place."
Legislation to reform both laws was introduced in the last Congress, but was blocked by the chemical industry trade association, the American Chemistry Council.
In response to the study, the American Chemistry Council said in a statement Wednesday, "This study simply confirms these reassuring points: that consumers have minute exposures to BPA and DEHP from food sources, and that the substances do not stay in the body, but are quickly eliminated through natural means."
The industry group said, "Data from U.S. Centers for Disease Control and Prevention and Health Canada have shown that typical consumer exposure to BPA and DEHP, from all sources, is up to 1,000 times lower than government-established safe exposure levels."
"Consumers should feel confident that they can continue to eat healthy canned or packaged foods because materials intended for use in food contact are approved by the U.S. Food and Drug Administration," the industry group said.
"The findings of this food packaging study suggest that if the food and food-storage industries reformulated packaging to remove BPA and phthalates, or if there were a federal ban of these chemicals in food packaging, a large portion of the population would experience a rapid reduction in the levels of these chemicals in their bodies," said Dr. Gray.
"Industry and government need to ensure the safety of any substitute chemicals before they are put into use," she said.
"As long as the chemical industry dominates Congress and stifles these agencies," said Igrejas, "consumers will have look to the states and their own wits to protect themselves from toxic substances."
Suggestions from the Breast Cancer Fund and Silent Spring Institute for reducing exposure to BPA and DEHP include cooking at home with fresh foods.
They suggest making some changes in the kitchen, such as avoiding canned foods, choosing glass and stainless steel food and beverage containers, and not microwaving in plastic.
After aggregating the results of tests of 300 canned food products, the Breast Cancer Fund found that BPA especially leaches into canned foods that are acidic, salty or fatty. The group's recommendation of 10 canned foods to avoid to reduce BPA exposure are: coconut milk, soup, meat, vegetables, meals such as ravioli in sauce, juice, fish, beans, meal replacement drinks and fruit.
For more information or to download a shopper's guide, visit www.breastcancerfund.org.
Copyright Environment News Service (ENS) 2011. All rights reserved.