Consumer Reports' latest tests of canned foods, including soups, juice, tuna, and green beans, have found that almost all of the 19 name-brand foods tested contain measurable levels of Bisphenol A (BPA). The results are reported in the December 2009 issue and also available online. BPA, which has been used for years in clear plastic bottles and food-can liners, has been restricted in Canada and some U.S. states and municipalities because it has been linked to a wide array of health effects including reproductive abnormalities, heightened risk of breast and prostate cancers, diabetes, and heart disease. I've reported on BPA here, here, and here.
Federal guidelines currently put the daily upper limit of safe exposure at 50 micrograms of BPA per kilogram of body weight. But that level is based on a handful of experiments done in the 1980s rather than hundreds of more recent animal and laboratory studies indicating that serious health risks could result from much lower doses of BPA. Several animal studies show adverse effects, such as abnormal reproductive development, at exposures of 2.4 micrograms of BPA per kilogram of body weight per day, a dose that could be reached by a child eating one or a few servings daily or an adult daily diet that includes multiple servings of canned foods containing BPA levels comparable to some of the foods Consumer Reports tested.
In keeping with established practices that ensure an adequate margin of safety for human exposure, Consumer Reports' food-safety scientists recommend limiting daily exposure to BPA to one-thousandth of that level (standard safety limit setting practice), or 0.0024 micrograms per kilogram of body weight, significantly lower than FDA's current safety limit.
Consumer Reports tested three different samples of each canned item for BPA and found that the highest levels of BPA tests were found in some samples of canned green beans and canned soups. Canned Del Monte Fresh Cut Green Beans Blue Lake had the highest amount of BPA for a single sample, with levels ranging from 35.9 parts per billon (ppb) to 191 ppb. Progresso Vegetable Soup BPA levels ranged from 67 to 134 ppb. Campbell's Condensed Chicken Noodle Soup had BPA levels ranging from 54.5 to 102 ppb.
Average amounts in tested products varied widely. In most items tested, such as canned corn, chili, tomato sauce, and corned beef, BPA levels ranged from trace amounts to about 32 ppb. (A microgram BPA /kg food is equivalent to a ppb level found in food, the only difference being that it's a microgram of BPA/kg of food tested versus the exposure or dose limits of microgram of BPA/kg of a person's body weight per day. So, in the example of the green beans, based on one serving of the average level from three cans tested, the average concentration is 123.5ppb of BPA in the can, the next conversion is to ug BPA per serving, 14.9 ug BPA / serving of green beans, so for a small child (22lbs or 10kg) that would calculate to 1.49 ug BPA/kg-bw and for an adult (example used in the magazine, 165lb, 75kg) .20 ug BPA/kg bw for a 75kg adult.)
The study also revealed that bypassing metal cans in favor of other packaging such as plastic containers or bags might lower but not eliminate exposure to BPA, but this wasn't true for all products tested. In addition, BPA was found in some products labeled as "organic" and some cans that claimed to be "BPA-free."
"The findings are noteworthy because they indicate the extent of potential exposure," said Dr. Urvashi Rangan, Director of Technical Policy, at Consumers Union, nonprofit publisher of Consumer Reports. "Children eating multiple servings per day of canned foods with BPA levels comparable to the ones we found in some tested products could get a dose of BPA near levels that have caused adverse effects in several animal studies. The lack of any safety margin between the levels that cause harm in animals and those that people could potentially ingest from canned foods has been inadequately addressed by the FDA to date."
Consumers Union has previously called on manufacturers and government agencies to act to eliminate the use of BPA in all materials that come in contact with food and beverages. An FDA special scientific advisory panel reported in late 2008 that the agency's basis for setting safety standards to protect consumers was inadequate and should be reevaluated. A congressional subcommittee determined in 2009 that the agency relied too heavily on studies sponsored by the American Plastics Council.
Given the new findings, Consumers Union sent a letter to Food and Drug Administration (FDA) Commissioner Margaret Hamburg reiterating its request that the agency act this year to ban the use of BPA in food- and beverage-contact materials. FDA is expected to announce the findings of its most recent reassessment of the safety of BPA by the end of this month. Bills are currently pending in Congress that would ban the use of BPA in all food and beverage containers. Industry has been waging a fight against new regulations, and California Assembly members recently voted not to ban BPA from feeding products for children under three.
Consumer Reports is advising those who are concerned that they might be able to reduce, though not necessarily eliminate, their dietary exposure to BPA by taking the following steps:
Choose fresh food whenever possible. Consider alternatives to canned food, beverages, juices, and infant formula. Use glass containers when heating food in microwave ovens.