(DougCookRD.com) BPA, or bisphenol A, a chemical commonly found in the food supply via packaging, is getting a lot of attention lately.
In a recent study, published in the Journal of the American Medical Association from the Harvard School of Public Health, volunteers experienced a 1,221% increase in urinary BPA after eating a can of soup per day for five days in a row. This is one of a very few studies that have measured levels of BPA in humans after consuming canned products.
Why this is important is because few studies have examined the impact of canned foods on BPA exposure and up until now, most anti-BPA advocates have argued that BPA’s mere presence in the food supply is enough to call it dangerous.
As lead author of the study, Jenny Carwile states….
“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.”
What is BPA?
BPA is a compound that is used to make plastics such as water bottles, drink cans, food storage containers and epoxy resins which are used to lined the inside of cans; it’s the white coating that overs the inside of the can. Look for it the next time you open a can of food.
One quick way to check if a plastic container likely contains BPA is to look for the Resin Identification Code, or the ‘recycle’ code. According to the National Institute of Environmental Health Sciences, “In general, plastics that are marked with Resin Identification Codes 1, 2, 3, 4, 5, and 6 are very unlikely to contain BPA. Some, but not all, plastics that are marked with the Resin Identification Code 7 may be made with BPA.”
At least 3.6 million tonnes (8 billion pounds) of BPA are used by manufacturers every year.
What is the concern about BPA?
BPA is what’s referred to as estrogenic meaning it has estrogen-like activity. In fact, BPA was researched as a possible early form of birth control. Research has shown that it can interfere with reproductive development in animal models, including humans. BPA levels in blood and urine have been associated with, but not proven to cause, higher risks of obesity, type 2 diabetes, and cardiovascular disease because it has the potential to disrupt hormones.
While the evidence is unclear as to whether or not levels found in packaging, and subsequently what turns up in the blood and urine, is harmful, more and more countries are taking the stance that BPA is a concern especially for fetuses, infants and young children.
The USDA expressed concern about it being problem for fetuses etc in 2008 but failed to take measures to remove it from baby related products. Canada, the first country to do so, declared BPA a toxic substance in 2010 banning it, like the European Union, in baby bottles.
According to Health Canada, this is where the real concern lies. It’s estimated that the Probable Daily Intake of BPA for infants ages 1 to 12 months can range from 0.083 ug/kg of body weight per day, up to 0.164 ug/kg because BPA is found in canned liquid infant formula products, canned powdered infant formula products, and baby food products in pre-packaged glass jars with metal lids. As a group, infants are exposed to the greatest amount of BPA as infants consume more food per unit (kg) of body weight relative to adults.
But exposure continues via packaging.
BPA from canned soup
The Harvard study wanted to know what the impact of commonly used, BPA-containing foods, had on urinary BPA. If it’s coming out in the pee, it’s getting absorbed. Volunteers ate one can of vegetarian soup daily for five days in a row followed by a two day break and then five servings of a same-sized portion of 100% homemade soup using fresh ingredients.
The BPA in the urine increased 1,221% after eating the canned soup.
The real question is whether or not this is meaningful. Does the estimated amount of BPA that Canadian adults get on average, about 0.043 ug/kg of body weight per day, pose a problem? I don’t know, and the best evidence suggests we don’t have an a definitive answer. In the US, the National Toxicology Program Expert Panel Report puts the estimated adult intake to be higher ranging from 0.008 to 1.5 ug/kg of body weight.
The Center for Disease Control rates the concern of BPA exposure from a ‘negligible’ to ‘serious’ concern.
Developmental toxicity for fetuses, infants and children [brain, behaviour, prostate]: some concern for adverse effects
Developmental toxicity for fetuses, infants and children [mammary gland, early puberty in females]: minimal concern
Reproductive toxicity in adult men & women: negligible concern for adverse effects
For more information, check out the Nat Toxicology Prgm BPA Fact Sheet
Regardless, more and more companies not waiting for the research to be conclusive and are responding to consumer demand by opting to remove the epoxy resin from the inside of cans. Eden Organics was one of the first, if not the first, company to offer BPA free canned goods
What this study did show was that blood, and subsequently urinary levels, of BPA increased rapidly after one just one serving of canned soup and this may be a concern for those who use a lot of canned products that have epoxy resin. This can be further compounded if cheaper plastic containers are used to store leftovers.
Reducing exposure to BPA
Check out the following links to learn how you can reduce your exposure to BPA, you can also choose foods package in glass bottles or BPA-free like Eden Foods
8 Ways to Reduce Your Exposure to BPA
How to Reduce BPA Levels by 60% in 3 Days
BPA: Reducing Your Exposure
Photo credit: CBC