Microwaving Food FAQs

What was food reheating like before the microwave was invented? Reheating foods, though easy enough when done the old-fashioned way, became infinitely easier with a microwave oven. You can use the microwave oven to reheat everything from leftover pizzas to week-old soups. The purpose of modern microwave ovens is no longer limited to reheating foods. They are now used to whip up a variety of dishes too.

But despite the many benefits of using a microwave oven, many people are wary of the safety of using microwave oven often. These health concerns stemmed from the fact that microwave ovens produce radiation to heat foods. Some people believe that the radiation could cause the heated foods to become “radioactive.” It does not help that there is so much misleading info about using a microwave oven in cooking. To set the record straight, we are dishing out fact-based answers to frequently asked questions about microwaving.

A microwave

Image used under Creative Commons from Breville USA

Is Microwaving Food Bad for You?

No, microwaving foods is not bad for you. In fact, there is no science-based study or clinical research that could prove that microwaving could harm human health at all. On the contrary, microwaving foods is deemed as one of the safest ways to cook and reheat foods. One study even compared the safeness of microwaving to steaming foods.

To understand the safety of microwaving, you need to know how a microwave oven warms up food. The oven comes with a generator that produces a form of radiation called microwaves. Those microwaves cause the water molecules inside food to vibrate. As the water molecules vibrate at rapid speeds, heat is produced. The heat is then absorbed by the food being reheated, cooking the food from within. The process of vibrating the water molecules within the food is similar to the way the hands produce heat when rubbed together.

Does Microwaving Make Reheated Foods Radioactive?

The word “radiation” can be quite scary because the term brings to mind post-apocalyptic doomsday scenarios. What’s important to know is that radiation refers to energy radiating from a source and not to radioactivity. In other words, radiation has nothing to do with radioactivity. That being said, there is a thing or two that you should know about radiation.

Radiation comes in many types, some are harmless, others, not so much. The radiation associated with microwave ovens is the non-ionizing kind. It’s the kind of radiation that only cause water to vibrate and not cause cancer or birth defects.

Non-ionizing radiation can move things around in the cells. However, it cannot alter a person’s DNA nor cause chemical changes around or within healthy cells. This means the radiation associated with microwave ovens is perfectly safe. There is no scientific evidence that it could harm you. It is also worth noting that the radiation that a microwave oven produces stays inside the oven.

Microwaving food

Image used under Creative Commons from Larry Jacobsen

Does Microwaving Destroy the Nutrients from Reheated Foods?

Cooking different types of foods cause physical, chemical, and nutritional changes. This goes no matter what cooking methods you use. That being said, rapid cooking is unlikely to affect the nutrient content of foods as long as you used the right combination of time and temperature during microwaving.

Cooking any type of food for a long, long time will lead to nutrient loss. Some nutrients can be temperature sensitive too. Vitamin C, in particular, is often lost once the food has been cooked for too long. However, reheating foods in a microwave oven will not lead to nutrient loss as long as the food has been reheated quickly. You are more likely to lose precious nutrients from boiling foods for too long compared to microwaving the same kind of food in minutes.

How to Thaw Food in a Microwave?

Apart from cooking and reheating foods, you can also use the microwave ovens to thaw frozen foods. In fact, most if not all modern microwave ovens come with a “defrost” option. This feature lowers the power setting significantly to defrost frozen solid foods.

To thaw frozen foods using a microwave oven, set the microwave oven to defrost. If your microwave doesn’t come with a “defrost” option, simply set the power setting to 50%. The time you need to defrost depends on the type and amount of food that needs defrosting.

Rather than giving you a spreadsheet with a million entries, I’ll give you a simple rule: use short time periods and examine the food after each short microwaving session. If the session didn’t have much effect, you can extend the period. When you notice the food is close to defrosted, shorten the period. Watching the food closely while defrosting in the microwave is very important. Otherwise, you can end up with a half-cooked dish, and in most cases, it’s not what you want.

Once the food has been defrosted completely, you should cook it as soon as possible. Or reheat it in the microwave if that’s what you prefer.