The findings were published in the Journal of the American Medical Association (JAMA).
In 2009, the North American Metal Packaging Alliance, a Washington-based trade group for can makers, said that “there is no readily available” alternative to BPA, which allows high temperature sterilization of canned food, preventing microbial contamination.
“Previous studies have linked elevated BPA levels with adverse health effects. The next step was to figure out how people are getting exposed to BPA. We've known for a while that drinking beverages that have been stored in certain hard plastics can increase the amount of BPA in your body. This study suggests that canned foods may be an even greater concern, especially given their wide use,” said Jenny Carwile, a doctoral student in the Department of Epidemiology at HSPH and lead author of the study.
BPA is a dangerous chemical linked to health concerns from digestive problems to issues with brain development. It’s was found present in around two billion products in the U.S. that are used on a daily basis. Because it’s the most harmful on developing brains and bodies, children and pregnant women especially need to avoid contact with BPA.
“When it comes to BPA in the environment, the biggest exposure, in my opinion, is from cash register receipts,” says John C. Warner of the Warner Babcock Institute for Green Chemistry (WBI), in Wilmington, Mass. “Once on the fingers, BPA can be transferred to the mouth, onto food, and likely absorbed through the skin.”
Canned products are another majory source of exposure. Simply put, just about anything you eat that comes out of a can -- from Campbell's Chicken Soup and SpaghettiOs to Diet Coke and BumbleBee Tuna -- contains BPA.
Other sources include PVC water lines, paper currency, dental sealants and plastics.
Other plastics--even BPA-free ones--may also be a source of endocrine disrupters. An analysis of more than 450 everyday plastic products, from plastic bags to water bottles, found that about 95% of the items tested leached chemicals that triggered a bioassay for estrogenic activity, including most of the products labeled as BPA-free (C&EN, March 14, page 48).
Even new products containing the BPA replacement, BPS has some of the same estrogen-mimicking effects of BPA, and that people may now be absorbing 19 times more BPS through their skin than when BPA was used to coat paper.
Stop Using Cans And Other BPA Lined Products
- Buy whole foods -- and carry them home in paper bags.
- Do not microwave in plastic -- even if it is labeled "microwave-safe"! Heat raises BPA levels in plastic, upping the health hazards. Instead, microwave food in glass or ceramic containers if you must use a microwave at all (please review dangers of microwaving)
- Consider switching to a French press coffeemaker. Typical coffeemakers may contain traces of BPA and other toxins in the bin that holds the coffee filter and coffee. These grow more concentrated when heated.
- Kick the cans. Avoid canned foods except those that are in BPA-free cans, such as from Eden Foods, Vital Choice, Oregon's Choice and Trident Seafoods.
- Watch out for the kids. Developing children are at even greater risk for harm from BPA. Use glass baby bottles or BPA-free plastic bottles. For older children, get stainless steel lunch boxes instead of plastic.
- Most types of cash register receipts contain BPA. Since it’s a “free” form of the chemical, that means it gets onto your hands and into your body in greater quantity than with some of these other products. If possible, just say no to the receipt when you’re at the store. If you do handle receipts, wash your hands as soon as possible, especially before handling food. You can also ask the store manager if they’re using BPA free receipts. The types that do not contain BPA are thermal paper from Appleton Paper or regular “bond” paper where the information is printed onto the receipt using ink.
The exposure to BPA from canned food "is far more extensive" than from plastic bottles, said Shanna Swan, a professor and researcher at the University of Rochester in New York. "It's particularly concerning when it's lining infant formula cans."
One scientist helping to lead the charge against BPA is Yale University physician, professor and researcher Hugh Taylor. His research has shown that the chemical alters the way genes react to estrogen, and could open the door for infants in utero to develop cancer much later in life.
"I tell my pregnant patients to avoid products containing it," he said. "Even a fleeting exposure in pregnancy can cause lasting damage."
The studies by Taylor are certainly eye-opening. They have shown that the chemical alters the way DNA operates, a process known as an epigenetic change.
Exposure to the endocrine-disrupting chemical BPA, used in the lining of metal food and beverage cans, has been shown to interfere with reproductive development in animals and has been linked with cardiovascular disease, diabetes, and obesity in humans. In addition to the lining of food and beverage cans, BPA is also found in polycarbonate bottles (identified by the recycling number 7) and dentistry composites and sealants.
Urine samples of the 75 volunteers taken during the testing showed that consumption of a serving of canned soup daily was associated with a 1,221% increase in BPA compared to levels in urine collected after consumption of fresh soup.
The researchers note that the elevation in urinary BPA concentrations may be temporary and that further research is needed to quantify its duration.
“The magnitude of the rise in urinary BPA we observed after just one serving of soup was unexpected and may be of concern among individuals who regularly consume foods from cans or drink several canned beverages daily. It may be advisable for manufacturers to consider eliminating BPA from can linings,” said Michels, senior author of the study.
April McCarthy is a community journalist playing an active role reporting and analyzing world events to advance our health and eco-friendly initiatives.