One of the marvels of modern technology is the microwave. Never has reheating or preparing food been so convenient, thanks to the help of this almost ubiquitous kitchen appliance. No one questions the microwave’s convenience, but there are people who are concerned about the safety of using this time-saving domestic marvel. What are those waves that emanate from your microwave, the ones that heat up food so quickly? Most importantly, are you exposing yourself to something that’s harmful when you microwave a plate of leftovers?
How Microwaves Work
When you place something in the microwave and turn it on, the appliance spits out waves called microwaves. These waves have enough energy to vibrate the molecules of the food or liquid you’re cooking. These vibrations generate heat and turn your cold, lifeless leftovers into something warm and satisfying.
Some people confuse the waves that a microwave produces with high-energy waves like x-rays. X-rays are a form of ionizing radiation – x-rays that damage tissues, cells and the genetic material inside cells. At even low doses this type of damage is linked with cancer.
Here’s the good news. Microwaves are not x-rays and they don’t make foods radioactive. They’re a form of radiation that’s much lower in energy compared to x-rays, similar to the waves used in broadcasting. As a result, they don’t cause the same cell disruption and havoc as x-rays. We’re exposed to microwaves all the time from mobile phones and computers. Why do people question the safety of microwave ovens? Some people believe microwaves change the chemical bonds in food in a way that makes them toxic.
Is there any evidence to support this? A Swiss scientist reportedly did a study showing eating food cooked in a microwave oven was linked to changes in blood cells. Most scientists’ label this study as “junk science” since it was poorly conducted with numerous flaws. Based on current research, there’s no evidence that microwave cooking changes the composition of food. The radiation released inside the microwave heats up the food without changing its chemical bonds much like heat from a stove or oven.
On the other hand, it wouldn’t be smart to stick your hand inside a microwave and turn it on, not that the microwave will work with the door open anyway. If you expose your skin to high levels of microwaves, it can cause a burn. High doses of microwave radiation are also linked with cataracts and fertility problems, although the exposure you need to cause this type of injury is much more than the amount that could leak out of a microwave oven.
Microwave ovens are constructed to keep the microwaves they produce inside the oven. Standards are set so that only a certain amount of radiation can escape from the oven over its lifetime. The amount allowed is well below the quantity that could be harmful. Plus, once the microwave stops, the radiation stops. It doesn’t hang around inside the oven and pose a risk when you open it. Still, it’s a good idea to regularly check your microwave to make sure the door latches securely to ensure the radiation stays inside.
Possible Risks of Microwave Cooking
It’s highly unlikely that microwave cooking changes the chemical structure of food, and your risk of being exposed to unhealthy amounts of microwave radiation is extremely low as long as you aren’t using a defective microwave with a leak. Still, microwave cooking has some potential risks you should be aware of.
Beverages heated in a microwave are subject to a phenomenon called super-heating. When you place a cup of water in a microwave to heat up for coffee or tea, there’s the risk of overheating that water without seeing it boil. That’s because microwaved water can heat up past its boiling point without actually boiling. When you take this super-heated water out of the oven, stir or otherwise disturb it, it can explode. This is more likely to happen when there’s only water in the cup. If you add something like instant tea powder to the cup before microwaving it, the powder absorbs some of the heat and it’s less likely to self-destruct. You can also avoid this risk by only heating liquids in the microwave for short periods of time.
The container you use to microwave food or beverage can make what you’re eating or drinking unhealthy. Some microwaveable foods convenience foods are in containers made of plastic. When you heat the container in the microwave, plastic compounds can leach into the food. One type of compound in plastic called BPA is under scrutiny right now for, possibly, being unsafe. It’s safest to microwave foods in food-approved ceramic dishes or glass.
Another potential risk is under-cooked food. Microwaves heat up food unevenly, so you could have uncooked portions even if the outside is hot. Food that’s uncooked in spots can harbor bacteria that cause food poisoning.
Does Microwaving Destroy the Nutritional Value of Foods?
If you limit the amount of water you use, microwave cooking results in a minimal nutrient loss. Some studies show microwaving leads to less nutrient loss than other cooking methods, with the exception of steaming, because the cooking time is shorter. From a nutritional standpoint, microwaving offers benefits over many other cooking methods as long as you limit the water.
The Bottom Line
There’s no evidence that microwaving food or beverages makes them less healthy from a nutritional standpoint or changes their chemical structure. As long as you use a microwave that doesn’t have a leak, you shouldn’t be exposed to unhealthy amounts of microwave radiation. For added reassurance, stand at least two feet from the microwave door when microwaving something. Don’t give your microwave away just yet. Microwaving is a fast and convenient way to get something healthy on the table.
References:
“Is Microwave Cooking Bad for Your Health? – Safety and Side Effects” Charlie Seltzer M.D.
U.S. Food and Drug Administration. “Microwave Oven Radiation”
Consumer Reports. “Microwaves that heat unevenly can pose food safety problems”
The Harvard Medical School Family Health Guide. “Microwave cooking and nutrition”
Bauman College. “Microwave Ovens: What Do We Really Know?”
