Ask Tufts Experts

I recently read that one shouldn’t microwave food in plastic containers because carcinogens are released into the food. Does this apply to all plastic containers, even those specifically designed for microwaving?

The supposed risks of carcinogens leaching from plastic into food when microwaved have reached the status of urban legend. The US Food and Drug Administration (FDA) has tried to reassure the public, noting that “the FDA carefully reviews the substances used to make plastics designed for food use.” Yes, says FDA consumer-safety official Edward Machuga, PhD, substances used to make plastics can leach into food. “But as part of the approval process, the FDA considers the amount of a substance expected to migrate into food and the toxicological concerns about the particular chemical.” As long as you use plastics as intended—don’t microwave restaurant carryout containers or margarine tubs, for example—you can microwave with confidence.

Do dried sweetened cranberries contain vitamin C?

Although dried fruits provide more fiber by weight than fresh fruits, otherwise they may not be as nutritious because their vitamins are often diminished in processing. Cranberries are known for their vitamin C—captains of sailing ships used to stock them to prevent scurvy—and a cup of fresh cranberries contains almost a quarter of the Recommended Daily Value of vitamin C. But dried sweetened cranberries, such as those sold under the brand name Craisins, have almost zero vitamin C. What they do have is sugar—93 grams per cup versus 3 grams in fresh cranberries.