Before you reach for canned foods, you should know what’s really inside of them. (Photo: Corbis/Michele Constantini)
For more than a decade, you’ve been hearing about the dangers of the hormone-disrupting chemical bisphenol A (BPA), found in everything from receipts to the lining of food cans. The chemical has been removed for the most part from baby bottles and water bottles, thanks to pressure (and pocketbook voting) from consumers.
BPA-free canned food brands include Amy’s, Earth’s Best Organic, Tyson, and Health Valley, according to a recent analysis. (Graphic: Copyright © Environmental Working Group, www.ewg.org. Reprinted with permission.)
Experts from the EWG spent eight months contacting companies, hunting down publicly available information, and following up with brand representatives to assess whether or not the brands used BPA to line their food cans. The project was part of the research conducted for the EWG’s Food Scores database.
Thirty-four brands had transitioned some, but not all, of their food options to BPA-free cans. More than 100 of the brands fell into the “unclear” category. “There’s a lot of ambiguity in what companies say, and we really had to dig to figure out what was really going on,” Renée Sharp, head of research for the EWG, tells Yahoo Health. “We did a lot of work — a lot of work the consumer won’t have to do — and it’s still a confusing landscape.”
Brands that were classified as “unclear” were those that didn’t confirm or clearly communicate whether or not they used BPA in their cans, says EWG database analyst Samara Geller. They include Walmart’s Great Value brand, Ortega, and Kroger.
“It’s a really broad category of companies, by far the largest group of brands we categorized in our analysis,” Geller tells Yahoo Health. “We had to read between the lines.” Some brands told researchers, for example, that they were researching BPA substitutes or conducting testing or that their suppliers were working on it.
Recent Studies Confirm BPA Dangers
BPA in the lining of cans is concerning because it leaches into the food. When you eat that food, BPA enters the body and acts on the body’s hormonal systems. Food is the main source of BPA exposure in humans, according to the National Institute of Environmental Health Sciences.
While much of the past research on BPA’s health effects has been on animals, "most of the human research has been done in the past two to three years,” says Johanna Rochester, a research associate with the independent Endocrine Disruption Exchange who studies endocrine-disrupting chemicals and who was not involved in the EWG report. “We have learned that BPA exposure is linked to a wide range of health effects in adults and children,” she tells Yahoo Health.
“There’s been a huge amount of research in the last few years on BPA,” Sharp confirms. “If you’re looking at the scientific research that’s independently funded, what you see is pretty much overwhelming evidence that BPA is toxic to a variety of health endpoints.”
Studying BPA in humans is difficult, explains Laura Vandenberg, assistant professor of environmental health sciences at the University of Massachusetts Amherst, who was also not involved in the new EWG report. “We are all exposed to this compound, so there isn’t an ‘unexposed’ group as a comparison,” Vandenberg tells Yahoo Health. “This is quite different from a drug, where some people that were prescribed the drug can be compared to others that were not.”
Because studies that would randomly expose humans to BPA on purpose would be unethical, most experiments have been conducted on animals. Even with these limitations, numerous recent human studies link BPA exposure to a number of health conditions and changes to the reproductive system, including sperm and embryo quality, altered thyroid hormone and sex hormone concentrations, and type 2 diabetes and cardiovascular disease.
A literature review by Rochester, published in the journal Reproductive Toxicology, concluded that “[the body of research] provides increasing support that environmental BPA exposure can be harmful to humans, especially in regards to behavioral and other effects in children.”
In addition, many scientists now believe that even very small amounts of BPA can cause health problems. For some chemicals, the higher the dose, the stronger the effect. But other chemicals follow a U-shaped curve. That is, there are strong effects at small doses, fewer effects at moderate levels, and strong effects at higher amounts. BPA is one of these chemicals, according to (most recently) an August 2014 research review published in Environmental Health Perspectives. “This might sound counterintuitive, but these U-shaped curves are very common for hormones, vitamins, and many pharmaceuticals,” Vandenberg says.
This pattern is important for several reasons, Rochester explains. It means that low levels of exposure to BPA, like those we encounter in everyday life, may potentially have more troublesome effects than moderate exposures. And, “the fact that these chemicals are active at very low levels indicates they are acting through hormone systems in the body, which naturally act at extremely low levels,” she adds. “There may not be a safe dose for human exposure.”
Hormones affect the body in extremely small amounts — “the parts-per-trillion level,” Sharp explains — so even BPA in parts-per-billion levels can be quite significant. (The current standard set by the European Union limits BPA to 600 parts per billion; the U.S. does not regulate BPA in foods.)
“Our bodies are very intricate, and the chemistry that happens in our bodies is very intricate, and it can be altered,” Sharp adds. “When it comes to BPA, it’s particularly the early-life exposures that we’re especially concerned about.”
Why So Many Cans Still Contain BPA
Removing BPA from cans is more technically challenging than taking it out of baby bottles, Sharp says. Manufacturers have to ensure that the can lining won’t break down or affect the flavor of the food after weeks, months, or even years on shelves.
“When [companies are testing BPA substitutes], a lot of times they’re just not quite meeting the standards that these companies have for freshness, shelf life, and flavor,” Geller says. “There are certain technical issues with food safety that they’re still trying to address.”
In addition, certain foods can be more troublesome than others. “I did note a tendency to see more of a transition in low-acid product categories, such as beans,” Geller says. “Whereas, some companies that have perhaps transitioned everything else are still not able to do something like tomatoes, which is a high-acid product.”
Experts also caution that the replacements for BPA need to be tested for safety. “BPA is a known toxin. It is definitely not something people want to be consuming, and there’s really no doubt about that,” Sharp says. “But there’s a lot that we don’t know about the alternatives, and there’s definitely been some research on some of the alternative chemicals that is concerning.”
Bisphenol S (BPS), for example, has been adopted as one alternative to BPA. But preliminary studies have shown neurological changes in animals exposed to small amounts of the chemical. Vandenberg underscores that more research is needed to find safe BPA alternatives. “What we don’t want is for BPA to be replaced by another chemical that also can act like estrogen, like BPS. We have seen these so-called 'regrettable replacements’ with many plastics — BPA replaced by BPS — and it is missing the point,” she says.
Vandenberg also points out that many people can only afford healthy foods, such as vegetables, in cans. "These individuals should continue to eat healthy foods!” she urges.
In a statement to Yahoo Health, the Grocery Manufacturer’s Association says, “The Grocery Manufacturers Association supports the FDA’s advice to consumers that food and beverages in packages using bisphenol A as a food safety barrier are safe and that packaging that may contain trace amounts of BPA are safe for use with food. We agree with FDA that there is no need for consumers to change their purchasing or consumption patterns.”
Sharp concludes, “We’re giving people information because we think it’s important and we want to push the market, but at the same time, we really need a much more comprehensive solution.”
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