We may want to pass on the canned green beans and cranberry sauce this holiday season. According to a new Harvard study, people who consumed a daily serving of canned food for five days showed a significant spike in BPA levels. BPA, or bisphenol-A, is an industrial chemical found in many plastics, including baby bottles, Nalgene’s (remember those?), and evencash register receipts. The substance raises some red flags, since it could increase risk of cancer, heart disease, and other health problems.

The study tested levels of BPA in urine, and people who consumed fresh soup showed average BPA levels, while those who ate canned soup showed a whopping 1,000 percent increase. (Who knew canned cream of mushroom soup packed more than just sodium and fat?!)

Still, don’t throw away all those cans of Campbell’s. The study didn’t track how quickly the BPA spikes returned to normal, or the actual health affects of BPA exposure. Some studies suggest there is no health risk, while sources like The National Toxicology Program are concerned BPA exposure could have harmful effects on the brain in fetuses and children.

Until researchers determine the health effects of BPA, perhaps we should just kick the can (of soup, that is). Opt for fresh fruits and veggies, since their canned counterparts could contain excess sodium.And for even higher-quality produce, try local fruits and veggies; it’ll not only cut back on fuel used to transport food, but the local stuff may also be better for your healthLocal, national and imported foods: a qualitative study. Chambers, S., Lobb, A., Butler, L., et al. Department of Agricultural and Food Economics, University of Reading, Reading, UK. Appetite, 2007 Jul;49(1):208-13..