The microwave can be summed up as the most commonly found kitchen appliance in most homes. It’s also the most feared for its so-called ‘harmful radiation’. It will be a rare microwave user who hasn’t heard of or worried about its use on health and food. From supposedly destroying all the nutrients in food to being compared to cancer-causing X-rays and ultraviolet rays, microwaves have been subjected to a lot of fear-mongering – and that is exactly what we will be exploring. By the end of this article, you will be ready to make an informed decision about them.
The Physics of It All
Let’s start by refreshing our memory with some basic high school physics. We were taught that there are a variety of electromagnetic waves (think: beams of energy) including visible light waves, gamma waves, radio waves, and microwaves. So, microwaves are high frequency waves. They:
- can be reflected off metallic materials (which is why you are told you shouldn’t put metal in a microwave).
- can pass through materials like glass and plastic (which is why you can heat food in glass containers and plastic that is not microwave-safe gets damaged).
- can be absorbed by materials like water (which is why you can boil water or other liquids in a microwave oven).
Inside the microwave oven, the emitted microwaves are absorbed by the molecules in food, causing the molecules to vibrate and creating heat that cooks or heats up the food. Basically, quantum physics are at play here and water molecules in food, which tend to be electrically polarised (meaning they have positively and negatively charged ends) and can be flipped by microwaves that have a specific amount of energy. It also means that you can’t cook anything in a microwave if it does not have enough moisture in it.
Microwaves are contained within the microwave oven and, as long as the door is undamaged and closes properly, it is safe to use this appliance in the kitchen. The waves do not stay in the food – they just excite the molecules – so there is no health risk from consuming microwaved food other than the potential of burning your hands or mouth from food that is too hot. There is a lot of fearmongering regarding the radiation produced, but compared to the rest of modern technology (cars, aeroplanes, or mobile phones), microwaves are nothing to worry about.
Does Cooking in a Microwave Oven Affect Food Quality?
There has been no significant nutritional difference detected between conventional cooking methods and microwaving. In general, there are no negative effects of using microwaves over any other cooking method (just don’t burn the food, which goes for every method). As well as being super convenient and useful, sticking to healthy eating is so much easier when you know you can warm up some homemade chicken and veggie noodles at work for lunch, rather than eating it cold.
As microwaving is a fast method of cooking, it actually may help some foods like vegetables retain nutrients that are lost during longer cooking times. In fact, microwave cooking has been shown to produce the lowest antioxidant losses in 20 vegetables when compared to pressure-cooking, boiling, or frying in this study. That’s really good news.
Is It Safe to Microwave Plastic?
It is safe to microwave plastic if the product explicitly says ”microwave safe”. The US Food and Drug Administration (FDA) recognised the potential for small amounts of plasticisers to migrate into food long ago, so it closely regulates plastic containers and materials that come into contact with food. The FDA requires manufacturers to validate these containers using tests that meet FDA standards and specifications. It then reviews test data before approving a container for microwave use.
Some of these tests measure the migration of chemicals at temperatures that the container or wrap is likely to encounter during ordinary use. For microwave approval, the agency estimates the ratio of plastic surface area to food, how long the container is likely to be in the microwave, how often a person is likely to eat from the container, and how hot the food can be expected to get during microwaving.
Regulators also measure chemicals that leach into food and the extent to which they migrate in different kinds of food. The maximum allowable amount is 100-1,000 times less per pound of body weight than the amount shown to harm laboratory animals over a lifetime of use. Only containers that pass this test can display a microwave-safe icon, the words ”microwave safe”, or words to the effect that they’re approved for use in microwave ovens.
What about containers without a microwave-safe label? They aren’t necessarily unsafe; the FDA simply hasn’t determined whether it is safe or not, so it’s your call to decide. Personally, I would use only those with the above label. Quoting my mentor and nutrition guru Martin MacDonald, “Remember, variety is the spice of life, so eat some foods raw, some others cooked, baked, boiled, steamed, microwaved. And that is about the only thing that unanimously brings about healthful outcomes.”
Ignore statements such as: microwave ovens will mess with your body’s energy fields; they use radiation that could be cancer-causing; they cause changes in HDL, LDL, white blood cells; or they will increase cholesterol oxidation products (COPs) that get easily absorbed in the gut and enter the bloodstream causing inflammation. Another classic? “They mess with your hormones.”
This is blatant misrepresentation of reality and, at best, will distract people from doing what they have to, which is to choose healthy habits to support an overall healthy lifestyle. This entails eating whole foods, moderating your food intake and matching it with your individual needs and goals, sleeping well, being consciously active, staying hydrated, and managing yourself around people and things that trigger a stress response by engaging in yoga or breathing exercises.
All of these are things we can focus on when it comes to prevention or delay in onset of diseases. Essentially, microwaves don’t make foods radioactive. They just heat them. It has never been proven that microwaves cause any harm through the foods we cook with them and, therefore, you shouldn’t worry every time you want to heat up that pot of soup or those leftover baked beans – as long as you follow the instructions that came with your microwave.
These include closing its door properly before hitting the start button as well as replacing old and broken microwaves. Use this nifty gadget without fear if you find it useful and convenient. You don’t need to use the microwave if it’s not your thing. I am not here to convince you to use it; I just want you to choose facts over fear.
Lovely Ranganath is a licensed clinical dietician in Dubai. Visit @good.food.guru for more information.