Fact vs. fiction

Nutrition Action Healthletter, April, 2005 by David Schardt

"In fact, my research suggests just the opposite."

Grilling of frying meat and poultry can create heterocyclic amines, which may cause cancer. When Felton and his colleagues briefly microwaved meats and drained off the juices before grilling, most of the precursors of those potential carcinogens were lost along with the juices. (1)

"I generally recommend that patients microwave their meats for one to five minutes and discard the juices before grilling," says researcher Cyndi Thomson of the Arizona Cancer Center at the University of Arizona in Tucson.

Nutrients

If you microwave your food, "you're zapping away nutrients and risking your health," charges physician Joseph Mercola, who recommends that consumers get rid of their microwave ovens and eat at least a third of their food raw.

"Actually, microwaving retains more nutrients than other forms of cooking, if you don't use a lot of water and don't overcook the food," says food scientist Barry Swanson.

"For some reason, people think heat breaks down vitamins, but most vitamins are really very stable to heat. Nutrients are mostly lost into the water, and there's no reason to add water to vegetables or anything else that already contains a lot of water."

Too much water was apparently the problem in a 2003 study in which European researchers reported that microwaving broccoli in a bowl of water destroyed nearly all of several flavonoids, while steaming had only a mild effect on them. (2) (Flavonoids are plant compounds that may help protect against heart disease and cancer, though the evidence is scanty.)

That research isn't relevant to household microwaving, says Swanson. "Basically, the researchers added far too much water and microwaved the living daylights out of the broccoli."

Wraps, Containers, & Packaging

How safe are plastic wraps, frozen-food trays, and "microwave-safe" containers and packaging?

* Plastic wrap. E-mails widely circulating around the Internet warn that plastic wraps release the carcinogen dioxin when microwaved.

"It's a chemical impossibility because the precursors for dioxin are not in the plastic wrap," says George Sadler, a professor of food packaging at the National Center for Food Safety and Technology in Summit, Illinois. The center is a consortium of scientists from academia, the Food and Drug Administration, and the food industry.

"We are not aware of any plastics that yield dioxin as a breakdown product, absolutely none," adds Kristina Paquette of the FDA's Office of Food Additive Safety in College Park, Maryland.

"I've seen another e-mail recently warning against using plastic wrap because of the phthalates it supposedly produces," says Sadler. (Phthalates make plastic flexible.) "Manufacturers quit using those many, many years ago."

While plastic food wrap hasn't been approved by the FDA for use in microwave ovens, says Paquette, "as long as the wrap doesn't touch the food while it's cooking, there's little chance of any chemicals migrating from the wrap into the food."

Besides, she notes, "there are no components of plastic wrap that are considered carcinogenic in humans."