When you need to heat up something fast, using a microwave is a convenient way to go. According to the USDA, over 90 percent of American homes have at least one. But their safety and effect on the nutritional value of food are subjects that yield frequently conflicting information

You’ve most likely read that microwave use can cause cancer. While disconcerting, this claim is based on only a few studies and thus is disputable. Do microwaves make food “radioactive”? According to the USDA, the answer is no. Microwave energy uses a wavelength similar to TV, radio waves, electric shavers and radar that is not radioactive. X-rays and nuclear radiation are at the other end of the spectrum and are a million times more powerful.

What about nutritional values of microwaved foods? A microwave heats by causing the food molecules to vibrate—an accelerated version of what ordinary cooking does. Heating, whether in the oven, on the stove or in a microwave, can change the chemical and physical composition of food. But more evidence from studies leans toward the fact that microwaving foods can reduce some nutritional value.

So what can/should you microwave? Heating liquids such as coffee or tea should be safe. When you’re heating foods, be sure to cook them in a microwave-safe container. Glass and ceramic containers and plastics that are safe usually will be labeled for microwave oven use. With recent concerns of unhealthy leakage from plastic, though, try and stick to glass and ceramic.

Keep in mind that microwaves can cook less evenly than a conventional oven, so it’s important to use a food thermometer particularly when cooking meat to ensure it has reached the recommended temperature to kill any bacteria. It also helps to cover your dish with a lid or plastic wrap as the moist heat created will help ensure uniform cooking. Finally, stirring, rotating or turning foods upside down (where possible) midway through the microwaving time helps even the cooking and eliminate cold spots where harmful bacteria can survive. Even if the microwave oven has a turntable, it’s still helpful to stir and turn food top to bottom. Visit www.fsis.usda.gov for more tips on microwave safety and cooking.