We can’t deny it— regardless of how delicious those slippery canned peach slices are, the syrup they’re packed in makes them a lot more like dessert than a serving of fruit. And canned veggies are often not so good either, often saturated with far more sodium than fresh or frozen versions. And let’s not forget about the potential harm that may be caused by eating produce with a side of BPA (that’s bisphenol A), often found in canned foods Determination of bisphenol a and bisphenol B residues in canned peeled tomatoes by reversed-phase liquid chromatography. Grumetto, L., Montesano, D., Seccia, S., et al. Dipartimento di Chimica Farmaceutica e Tossicologica, Università degli Studi di Napoli Federico II, Naples, Italy. Journal of Agricultural and Food Chemistry, 2008 Nov 26;56(22):10633-7. Determination of bisphenol A in canned vegetables and fruit by high performance liquid chromatography. Yoshida, T., Horie, M., Hoshino, Y., et al. Saitama Prefectural Institute of Public Health, 639-1, Kamiokubo, Urawa, Saitama 338-0824, Japan. Food Additives and Contaminants, 2001 Jan;18(1):69-75. .
Can-Can’t — The Need-to-Know
Lets dig into these unhealthy stowaways a bit further. Some studies have found BPA in about half of all canned foods tested (like tomatoes and soup), but not always at unsafe levels Determination of bisphenol a and bisphenol B residues in canned peeled tomatoes by reversed-phase liquid chromatography. Grumetto, L., Montesano, D., Seccia, S., et al. Dipartimento di Chimica Farmaceutica e Tossicologica, Università degli Studi di Napoli Federico II, Naples, Italy. Journal of Agricultural and Food Chemistry, 2008 Nov 26;56(22):10633-7. Bisphenol a in canned food products from canadian markets. Cao, X.L., Corriveau, J., Popovic, S. Food Research Division, Bureau of Chemical Safety, Food Directorate, Health Canada, 251 Frederick Banting Driveway, AL: 2203D, Ottawa, Ontario, Canada. Journal of Food Protection, 2010 Jun;73(6):1085-9. . However, a more recent study revealed a roughly 1,200 percent increase in the concentration of BPA in urine after study subjects ate canned food five days in a row Canned soup consumption and urinary bisphenol A: a randomized crossover trial. Carwile, J.L., Ye, X., Zhou, X., et al. Department of Epidemiology, Harvard School of Public Health, Boston, Massachusetts. JAMA, 2011 Nov 23;306(20):2218-20. . While many scientists agree BPA in cans can leach into produce, the effects are still unclear. Studies have suggested BPA exposure could lead to increased risk of breast cancer, birth defects, and emotional problems in young girls Exposure to the Endocrine Disruptor Bisphenol A Alters Susceptibility for Mammary Cancer. Lamartiniere, C.A., Jenkins, S., Betancourt, A.M., et al. Department of Pharmacology and Toxicology, University of Alabama at Birmingham, Birmingham, Alabama. Hormone Molecular Biology and Clinical Investigation, 2011 Mar 1;5(2):45-52. , but the some governmental agencies still reject many of these claims.
As for the dietary downsides of these dangerfoods, sugar and salt are both on the list of concerns. While a cup of water-packed fruit cocktail has about 76 calories and 18 grams of sugar, the same amount of syrup-packed fruit cocktail has up to 181 calories and 44 grams of sugar (almost 1.5 times the amount of sugar in a Snickers bar!). On the opposite end of the flavor spectrum, processed foods like canned vegetables often use salt as a preservative, resulting in ultra-high sodium content (like, say, 13 percent of the daily value from just ½ cup of canned green beans!). And that extra sodium could lead to higher blood pressure and increased risk of heart problems Long term effects of dietary sodium reduction on cardiovascular disease outcomes: observational follow-up of the trials of hypertension prevention (TOHP). Cook, N.R., Cutler, J.A., Obarzanek, E., et al. Brigham and Women's Hospital, Harvard Medical School, Boston, MA. BMJ, 2007 Apr 28;334(7599):885-8. Epub 2007 Apr 20. .
Kick the Can — Your Action Plan
Folks watching their sugar or calorie intake should do away with syrup-packed fruit in favor of fruit packed in water or juice. As for canned veggies, a 60-second rinse under running water removes about 40 percent of the sodium they’re packed in, but opting for fresh or frozen is the best way to reduce unnecessary sodium.
The bad news? Other than ditching canned foods altogether, there may not be a surefire way to ensure lower BPA intake when eating them. From time on the shelf to handling and storage, researchers have yet to figure out why BPA leaches into food— though some research suggests extreme heat (above boiling temperature) may leave more BPA behind Factors influencing the migration of bisphenol A from cans. Kang, J.H., Kito, K., Kondo, F. Department of Veterinary Public Health, Faculty of Agriculture, Miyazaki University, Kibanadai-Nishi, Gakuen, Miyazaki-shi 889-2192, Japan. Journal of Food Protection, 2003 Aug;66(8):1444-7. Migration of bisphenol A (BPA) from can coatings into a fatty-food simulant and tuna fish. Munguía-López, E.M., Gerardo-Lugo, S., Peralta, E., et al. Centro de Investigación en Alimentación y Desarrollo, A. C., Apdo. Postal 1725, Carret. a La Victoria km 0.6, Hermosillo, Son., 83000 México. Food Additives and Contaminants, 2005 Sep;22(9):892-8. Migration of bisphenol A from can coatings--effects of damage, storage conditions and heating. Goodson, A., Robin, H., Summerfield, W., et al. Pira International, Leatherhead, Surrey, KT22 7RU, UK. Food Additives and Contaminants, 2004 Oct;21(10):1015-26. . Salty and oily foods might also absorb more BPA than sugary foods, one study found, while another suggests the longer foods are stored, the more BPA is released into the food Factors influencing the migration of bisphenol A from cans. Kang, J.H., Kito, K., Kondo, F. Department of Veterinary Public Health, Faculty of Agriculture, Miyazaki University, Kibanadai-Nishi, Gakuen, Miyazaki-shi 889-2192, Japan. Journal of Food Protection, 2003 Aug;66(8):1444-7. Migration of bisphenol A (BPA) from epoxy can coatings to jalapeño peppers and an acid food simulant. Munguia-Lopez, E.M., Peralta, E., Gonzalez-Leon, A., et al. Centro de Investigacion en Alimentacion y Desarrollo, A.C. Apdo. Postal 1735, Hermosillo, Sonora 83000, Mexico. Journal of Agricultural and Food Chemistry, 2002 Dec 4;50(25):7299-302. . Another can concern is botulism, which can be caused by bacteria in canned goods. It’s rare in the U.S., but is typically found in bloated or damaged canned goods (because the protective seal has been broken), so avoid those cans!
I Think I Can, I Think I Can — The Greatist Beginner's Guide to Canning
Glass jars are a safe way to enjoy fruits and veggies year-round without fear of BPA and with control over ingredients. We rounded up quick and easy guidelines for first-time canners:
- Always use a recipe. Canning recipes are specifically formulated to preserve properly. Altering them slightly could result in the wrong level of acidity and unsafe food. Yeah, it’s basically like having a mad scientist’s lab in the kitchen.
- Start with fruit. Because of its natural acidity, fruit can be jarred with a standard kitchen pot, whereas vegetables require a pressure canner.
- Gear up. Use cans intended for canning (no left-over tomato sauce jars) with two-part lids (a flat top with rubber gasket, which should be new, and a ring, which can be reused).
- Use fruit at it’s best. Canning won’t improve the quality of the fruit, so avoid fruit that’s overripe or low-quality. Canning in-season helps.
- Have the right pot. Make sure your pot is large enough to accommodate the can, a rack underneath it, one to two inches of water over the top of the can, plus one to two inches between the water and the top of the pot (to leave space for boiling). Use canning tongs, which are coated with heat resistant rubber, not standard kitchen tongs.
Photo by Caitlin Covington