Food manufacturers face a dilemma when using cans to package their products. Cans are made from metal, which can leech into the food, especially with foods such as tomatoes, which are highly acidic. Cans made with linings, however, typically contain the chemical compound bisphenol-a, or BPA, which disrupts endocrine function. Due to widespread concern about health risks associated with BPA, some consumers avoid tomato cans whose linings are made with the chemical, and forward-thinking producers have begun searching for alternatives.
Tin and Unlined Cans
Although tin is a trace mineral that is necessary for healthy human development, ingesting excessive amounts may cause digestive issues such as nausea, vomiting and abdominal pain. According to ACU Cell Analysis, average daily tin consumption is about 1 to 3 milligrams. The Jovial food company tested 28 ounces of tomatoes stored in an unlined tin can, and found 38 milligrams of tin in the sample.
BPA, Tomatoes and Lined Cans
Because of concerns about tin leaching into canned tomatoes, many American companies began switching to lined cans during the 1960s. However, this solution was flawed because of the BPA in these plastic linings. According to the New York Times, Harvard University researchers found that blood BPA levels spiked dramatically after consumption of soup that had been stored in lined cans. Eating just one serving of canned food daily for five days elevated BPA levels tenfold. Tomatoes are especially likely to be stored in lined cans because their high acid content leeches tin when it comes into direct contact with the metal.
BPA Health Risks
The FDA considers the levels of BPA found in cans to be safe for human consumption, even for products like tomatoes. However, as of 2013, the agency is continuing to review information about the chemical's potential health risks. BPA is particularly problematic in its potential effect on brain and behavior in infants and children, as well as possible risks associated with prostate development..
Because both lined and unlined tomato cans pose possible health risks, some companies have been exploring other ways to package tomato products. Some of these options, such as asceptic packaging, are made with plastic and may contain other suspect chemicals. BPA-free can linings are relatively new and, although they have been approved by the FDA for food packaging, their relative risks and benefits are still not fully understood as of 2013. Glass jars are chemically stable and provide a sensible alternative for consumers wary of potential health risks posed by both lined and unlined cans.
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