
I admit it…I cook or warm up my toddler’s food in the microwave almost daily. With about 90 percent of American households owning a microwave, I am sure that most mothers are nuking their kids’ meals in this very useful kitchen appliance. However, I often wonder if cooking in the microwave is safe. (Note: My concern in this post is the microwave radiation itself being harmful, not the type of container used to hold the food—that is for another entry.)
How Does a Microwave Work?Microwaves are a form of electromagnetic radiation—waves of electrical and magnetic energy moving together through space. Microwaves fall into the radio frequency band of electromagnetic radiation, and are much less powerful than x-rays. Microwaves are good for cooking because they are reflected by metal; pass through glass, paper, plastic, and similar materials; and are absorbed by food.
Radiation Guidelines
Because there are still some questions about exposure to low levels of microwave radiation,
FDA continues to enforce radiation protection requirements.
The agency believes that ovens that meet its standard and are used according to the manufacturer's instructions are safe.
FDA’s standard limits the amount of radiation that can leak from a microwave oven throughout its lifetime to 5 milliwatts (mW) per square centimeter at approximately 2 inches from the oven surface. This is far below the level known to harm people. Microwave energy also decreases dramatically as one moves away from the source of radiation. In addition, FDA requires all microwave ovens to have two independent interlock systems that stop the production of microwaves if the latch is released or door is opened.
Current Research on RadiationAlthough additional research is needed, it has been found that high levels of radiation (much greater than FDA’s standard) from microwaves can cause burns, cataracts, and temporary sterility in men. Researchers are still trying to learn more about potential effects due to low levels of microwave radiation. Much research has been done with animals, but it is difficult to translate the effects of microwaves on animals to possible effects on humans.
Chemistry of FoodAnother concern is whether microwaves can alter food in a harmful way. The
Daily Green blogged about this topic, exploring both sides of the issue. On one hand, any type of cooking changes the chemistry of food, either increasing or decreasing nutrient levels. The site pointed out that the “prevailing view is that microwaves do not alter foods in ways that are any more deleterious or harmful than other types of cooking. In fact, some have argued that the faster cooking time may actually preserve more nutrients versus other methods.”
On the other hand, some experts are concerned that there is not enough information to confirm that microwaves do not damage food. Holistic health expert Dr. Andrew Weil has written about the possible dangers associated with microwaving food and whether it negatively alters protein chemistry. Also, Dr. Fumio Watanabe of Japan's Kochi Women's University found that heating samples milk in the microwave for six minutes degenerated 30-40% of vitamin B12. Finally, in the late 1980s Swiss scientists reported decreases in hemoglobin and white blood cells in rats that had eaten microwaved food.
How to Reduce Your Risk - Follow the manufacturer's instructions.
- Do not operate an oven if the door does not close firmly or is bent, warped, or otherwise damaged.
- Never use an oven if it will continue to operate with the door open.
- Do not stand directly against or in front of an oven for long periods of time while it is operating.
Please share your views. Do you use a microwave to heat your child's food? If not, what other cooking techniques do you use? Are you concerned about microwave radiation or altering the nutrients of the food?