The Cancer Danger in Canned Food

Independent research undertaken by the Breast Cancer Fund has uncovered harmful levels of Bisphenol A – or BPA – in a range of popular canned goods. Conducting the study using tinned foods commonly consumed throughout the festive season, including cranberry sauce, corn, green beans and evaporated milk, scientists found significant doses of the potentially dangerous chemical, which has been linked to an increased risk of breast cancer.

A common component of polycarbonate plastic used to make food containers, microwave ovenware, kitchen utensils and some baby bottles, BPA is also used in the epoxy-resin linings of tin cans to form a barrier between the metal and the food and prevent bacterial contamination.

However, the toxic chemical can leach from the resin and make its way into food. Conditions connected to regular consumption are varied and range from breast and prostate cancer, infertility and early puberty in girls to type-2 diabetes, obesity and attention deficit hyperactivity disorder.
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"The tests showed that single servings of almost half of the products had levels of BPA comparable to levels that laboratory studies have linked to adverse health effects," reported Shannon Coughlin of the Breast Cancer Fund. "When combined in a meal with other canned foods – even those with lower BPA content – the result could be a holiday meal that delivers a very concerning amount of BPA.

"Just one plate of your holiday favourites could deliver a potentially harmful dose of BPA. Then you get seconds. Then there's the leftovers. And then there's the rest of the year – most of us eat canned foods daily or weekly. Even if we don't use them much at home, canned foods are used in a lot of restaurant and cafeteria food. When you think of this daily exposure, you start to see the urgency of getting this chemical out of food cans."

Though this particular study was conducted in the US, Australian watchdogs have long been lobbying for change. Last year, a similar study by consumer group Choice found that 33 out of the 38 products they tested contained BPA. And just one serving of 29 of them delivered a dose that exceeded a safe daily level of exposure for a 70kg adult.

Caving to international pressure to ban the use of BPA, the Australian Government has implemented voluntary deal with major retailers. From last July, a gradual phase out of baby bottles and tinned baby food containing the chemical has been in effect. But the program was not extended to other products, citing the fact that Food Standards Australia New Zealand said existing levels were low and of no public threat. This view is disputed by researchers, with both the Choice and Breast Cancer Fund studies finding varying levels of BPA in the same brand of food after multiple tests.

"We tested four cans each of seven different products. We found a tremendous variability in BPA levels in the canned foods we tested, even among cans of the same product made by the same company, which means that consumers have no way of knowing how much BPA is in the canned food they're buying and consuming," said Coughlin. "These findings point to a troubling fact: consumers are being exposed to BPA through eating canned foods, and have absolutely no way of knowing what their levels of exposure might be."

Though some in the scientific community discount the links between BPA and an increased risk of breast cancer and other illnesses as junk science, clinical studies have proven the chemical's detrimental effects in both mice and human cell cultures. The European Union, Canada and China have banned the use of BPA in the production of baby bottles and France is on the verge of banning it in all food applications. The Endocrine Society, the world's oldest, largest and most active organisation devoted to research on hormones, issued its first-ever scientific statement on BPA in 2009, saying that it can interfere with human hormone systems even at acutely low doses.

"In regard to breast cancer, lab studies have shown that BPA alters mammary gland development in rats and mice. Prenatal exposures of rats and mice to BPA have also been shown to result in precancerous and mammary tumours," said Coughlin. "Furthermore, when scientists have exposed human cell cultures to BPA, they have seen increased breast cancer cell proliferation and damage to DNA.

"Recent research found that when pregnant mice drank water laced with BPA at environmentally relevant doses, it altered the long-term hormone response of their offspring in ways that could increase the offspring's risk for developing breast cancer. Even more worrying, recent evidence demonstrates that BPA exposure may reduce the efficacy of chemotherapeutic and hormonal treatments for breast cancer."

Recommending that the chemical be removed from all food packaging and ensuring that any replacement is proved to be safe, experts suggest that until that happens shoppers should opt for fresh or frozen foods and buy products in glass or Tetra Pak packaging wherever possible in order to avoid exposure and possible related health problems.

"Consumers have no way of assessing BPA levels just by looking at cans on supermarket shelves," added Coughlin. "The findings of this report highlight the urgent need to remove BPA from food packaging so that shoppers can be confident that the food they are purchasing is safe for their families — not only at Christmas, but every day."

The chemical is also found in soft drink and beer cans, with The Coca-Cola Company rejecting a move to ban it from their products in April this year. This comes after a 2009 Washington Post investigation that uncovered internal company memos which discussed plans to “devise a public relations and lobbying strategy to block government bans” of BPA in can linings.

Read more: http://www.smh.com.au/lifestyle/diet-and-fitness/the-cancer-danger-in-ca...