Dr. Katz
Photo: Mackenzie Stroh
Q: My friend's nutritionist advised her to get rid of her microwave because so many nutrients are lost in this type of cooking. Is that true? The nutritionist claims that you lose all the benefits of tea if you heat it in a microwave. 
— Marilyn Cooper, Medina, Ohio

A: Of all the ways to cook food, microwaving may be the least damaging to nutrients. Sources as varied as the American Cancer Society and the European Food Information Council—not to mention numerous studies—agree that these ovens are a nutritious way to cook.

Microwaves achieve their fast-cooking magic by vibrating water molecules in the food; in most cases, the less time a food is exposed to heat, the higher its nutrient levels. With tea, since you're microwaving only the water and adding the tea bag after, there's absolutely no way the nutrients could be adversely affected. Interestingly, when researchers looked at microwaving as a method for drying tea, the leaves had just as many cancer-fighting polyphenols and higher vitamin C content than with oven heating.

There's a movement made up of people who refer to themselves as raw foodists. They believe that any nutrients lost through cooking are too many. I think that goes too far. Heating tomatoes in a sauce that contains olive oil makes the antioxidant lycopene more absorbable. Cooking eggs makes biotin, a vitamin that helps manage blood sugar, more available, not less. Pasteurizing milk can prevent dangerous bacterial infections.

About the only argument against microwave cooking is that it can leave food drier or with a subtly different taste that some people dislike. But don't let anyone tell you that microwaving makes your diet less nutritious.