Should You Stop Eating Canned Foods?
Many nutritionists and physicians, when advising how to purchase the healthiest foods, recommend shopping around the perimeter of the store, where food is mostly fresh or frozen and of superior nutritional value. The majority of foods in the aisles are presented in shelf-stable packaging, such as canned foods, in an effort to provide a variety of food even out of season. But are these foods really less healthful, or is it just another myth to confuse a want-to-be healthy shopper?
Cans provide a reliable, durable package to keep foods and beverages fresh. The process of pasteurization, boiling, refrigeration, vacuum treatment and other methods used during the canning process prevents microorganisms from entering the food and growing, leading to a food borne illness such as E.coli or salmonella poisoning. Keep in mind, though, that the process is not completely impenetrable and some heat-resistant organisms, such as Clostridium botulinum, can still survive.
Despite some reports to the contrary, no reliable evidence has been found that the heating process during canning kills nutrients, making the foods less valuable as a good nutrition source. In fact, canning provides a cheap method for getting a variety of fruits and vegetables out of season, increasing the likelihood of someone reaching the goal of Five-a-day as recommended by many health experts, including the American Cancer Society and the American Heart Association.
Canned foods are almost always higher in sodium than their fresh or frozen counterparts. Salt, or sodium chloride, is often used as a preservative as well as a flavor-enhancer. Sodium intake is one factor that is involved in the development of high blood pressure. On average, Americans consume somewhere between 3,000 and 5,000 milligrams of sodium each day, much higher than the 2300 milligrams recommended. Rinsing some canned foods can be beneficial. For example, rinsing canned tuna for 3 minutes was shown to reduce sodium content by as much as 80% in one study. The rinsing did not affect the salt content of canned beans, however.
After a December Consumer Reports article, much media coverage has focused on Bisphenol-A (BPA) as a component of the resin lining inside most commercial food cans. BPA has been linked to an increased risk of many diseases, including cancer, diabetes, and obesity. The Food and Drug Administration is reviewing the available data to find if there is an acceptable amount of BPA to be allowed into the packaging of food products, particularly those that are marketed for children.
See Camilla's article on reducing your exposure to BPA.
The Bottom Line
Fresh and frozen foods are the recommended forms in order to gain the most nutritional benefit with the least side effects. However, canned foods can be healthful as well, particularly if they create a tendency to include more fruits and vegetables to the dinner plate. Be sure to look for BPA free cans, and rinse foods before eating to reduce sodium.