Winter 2014 True Natural Health Magazine – Your Questions Answered
By Roger French
QUESTION: What kind of plastic is used to line the insides of steel cans that contain food? Is it a plastic that releases BPA or other toxic chemicals?
Yes, many of the plastic linings inside food cans contain BPA (bisphenol-A). The question is – can we absorb enough BPA to cause harm?
BPA is a chemical which can mimic oestrogen and is linked to breast cancer and early puberty in women. In recent years, studies have linked this chemical to a range of diseases, including neurological problems, ADHD, thyroid function, digestive problems, obesity, heart disease and cancers. However, being ‘linked’ to a disease doesn’t necessarily mean that it causes it.
BPA linings are popular with can manufacturers because they are tough and durable, and prevent the food from corroding the steel of the can.
Because of uncertainties over BPA, Food Standards Australia New Zealand (FSANZ) has adopted fairly conservative upper limits of contamination in our bodies. However, even with this approach, there are calls for the standards for maximum daily intake to be revised down, and FSANZ is reviewing its BPA standards.
FSANZ has told Choice magazine (Sept 2010) that a survey found that the highest level of BPA was in canned baby custard. Using FSANZ’s figures, a baby weighing nine kilograms would have to eat more than one kilogram of this custard every day to obtain the upper limit of intake.
It appears that the amount of BPA in Australian canned food complies with FSANZ’s standards. However, whether or not this is safe depends entirely on the accuracy of the standards. Groups in the US and Europe are agitating that the current standards are too high and should be revised downwards. In fact, the US Natural Resources Defense Council has recently taken out a law suit against the US Food and Drug Administration for failing to ban BPA outright. This is powerful stuff!
In Denmark using BPA in baby food containers has been banned. This is wise, considering growing babies are far more susceptible to toxic chemicals than are adults. Similarly with foetuses, so BPA should not be consumed at all by pregnant women. It may not be long before there is agitation in Australia for a ban.
For adults, the big question is whether or not we can tolerate small amounts of toxic substances like BPA without harmful effects. The answer may be very elusive, because we are exposed to a vast number of toxic chemicals, even though most are in minute quantities.
Alternatives to BPA-containing plastics are available, but there is no way that we consumers can we tell if a can is lined with BPA.
Aluminium cans are more likely have linings that will give off traces of BPA. On the other hand, many steel cans don’t contain BPA plastics.
We asked a couple of brands of canned foods about their can linings and here are their responses.
Golden Circle and Heinz canned foods. Some of their plastic linings contain BPA and some don’t. Those that are free of it include the containers for infant foods, tomato sauce, juices, snack foods, frozen products and soups. Their information service explained that the lining is a lacquer designed to last the life of the can, although it will break down eventually. The colouring is titanium dioxide (as used in artificial joints) which is very stable. They pointed out that the FSANZ standard for BPA is a hundred times lower (meaning better) than is permitted in some other countries.
Edgell. Their packaging manager advised that Edgell can linings contain trace amounts of BPA, and during the cooking process some of this BPA leaches into the food. However, their tests found that the amount of BPA that is in the food is well below the European Union safe limit, which, they say, is the strictest in the world.
An unexpected source of BPA is receipts. The print-outs are typically made with thermal paper that contains BPA, and after handling receipts, the participants in a study were all found to have BPA in their urine. Research has shown that holding receipt paper for only five seconds was enough to transfer BPA onto your skin, and the amount increased by about 10 times if fingers were wet or greasy.
My conclusions from all this is that BPA should be kept well away from babies, young children and pregnant women. For the rest of us, I estimate that occasional use of BPA-lined canned food would probably result in insignificant levels of contamination of our bodies. However, fresh food is best anyway.