Once upon a time I was a hard core non-microwaver. I ditched my microwave in 2004 after deciding to make my indoor living space as natural as possible. Why did I need another appliance to spew radiation all over me and destroy the nutritive value of my food? I lived without one for 10 years, happily ditching my radiation-distributing convenience cooker and instead using my cast iron skillet or oven to rewarm food. I was convinced that microwaves scramble the molecules in food to heat/cook it, thereby damaging the proteins and destroying any nutritive value and delicate vitamins (like B and C vitamins, for example, which are very heat sensitive).
I once thought microwaves were a form of electromagnetic energy, like light waves or radio waves. They work by creating agitation, causing molecular friction, which heats up the food from the inside. This unusual type of heating causes substantial damage to the surrounding molecules, often tearing them apart or forcefully deforming them. This radiation results in the destruction and deformation of food molecules. Eating microwaved foods with denatured proteins can cause oxidative damage. But is that true?
Are Microwaves Safe?
Start researching the topic and you’ll be presented with strong opinions and “science” from both sides: One camp saying microwaves are perfectly safe, emit little radiation, and are energy-savers; the other camp saying microwaves damage food, contribute to cancer by making food carcinogenic, and lower your lymphocyte levels, therefore compromising your immune health. Who’s right?
For starters, microwaves are a very low frequency wave on the electromagnetic spectrum. They have slightly more energy than radio waves, and significantly less energy than visible light. Microwaves are a non-ionizing form of radiation, meaning they are not powerful enough to impart radioactivity to other substances. When applied in intense doses, however, it can cause polarized molecules to rotate, creating friction and heating the substance. This is how a microwave oven warms your food. (source: www.zocdoc.com).
The FDA says “Much research is under way on microwaves and how they might affect the human body. It is known that microwave radiation can heat body tissue the same way it heats food.” Gross. I doubt you’d be microwaving your hand or other body parts though?
And also, “Less is known about what happens to people exposed to low levels of microwaves. Controlled, long-term studies involving large numbers of people have not been conducted to assess the impact of low level microwave energy on humans. Much research has been done with experimental animals, but it is difficult to translate the effects of microwaves on animals to possible effects on humans.”
What this tells me is the jury is still out (and really, do you trust the FDA to have your best interests at heart?); however, exposure to the low levels of radiation emitted by microwaves apparently isn’t a problem. I tend to believe we function on a total load threshold, wherein constant and repeated exposure to all our devices, from computers to cell phones to ipads to wifi, all adds up and may cause health problems in sensitive individuals. Again, no conclusive data on that, but I tend to err on the side of caution and try not to hold my iphone next to my brain for extended periods (hands free device for talking on the phone), and I don’t have any electronic devices at all in my bedroom. As for the microwave, when using it, don’t stand in front of it.
Do Microwaves Destroy The Nutrients in Food?
In terms of nutritive value, heating/cooking food destroys nutrients, no matter if it’s done on a stovetop or in a microwave. Long, slow cooking at low temperatures (as in a crock pot) preserves the nutrients best. And cooking some foods, such as cruciferous veggies (broccoli, kale, cabbage, etc), enhances the nutritive value because it deactivates certain compounds like anti-nutrients that makes the food hard to digest and absorb, or goitrogens that suppress thyroid function. I was worried about a microwave “scrambling” or denaturing the protein or molecules in my food, somehow rendering it carcinogenic or prone to causing oxidative damage to cells. The FDS says, “Microwaves cause water molecules in food to vibrate, producing heat that cooks the food. That’s why foods high in water content, like fresh vegetables, can be cooked more quickly than other foods. The microwave energy is changed to heat as it is absorbed by food, and does not make food ‘radioactive’ or ‘contaminated.’ Although heat is produced directly in the food, microwave ovens do not cook food from the “inside out.” There is also some evidence that using the lower power settings on the microwave can retain more nutrients than stovetop cooking/frying/sauteeing. Chris Kresser does an excellent job discussing denatured proteins.
I’m beginning to change my tune about microwaving food. I purchased a simple microwave just to reheat food or melt coconut oil or butter (which is a pain on the stovetop). I wouldn’t use it or recommend it to cook food, like meat for example, because it tends to make food rubbery, and I’m still a bit creeped out by the thought of cooking something in a microwave vs just reheating it. And frankly I don’t prefer the taste of microwaved food.
I think today’s microwave models don’t emit as much radiation as their early model counterparts, and they can be quite energy efficient. But I still wouldn’t stand directly in front of it while it cooks, and I’m likely to use the lower power settings so I don’t zap the shit out of my food.
What about you? Are you pro or against microwave cooking?
Mary Vance is a Certified Nutrition Consultant and author specializing in digestive health. She combines a science-based approach with natural therapies to rebalance the body. In addition to her 1:1 coaching, she offers courses to help you heal your gut and improve your health. Mary lives in San Francisco and Lake Tahoe in Northern California. Read more about her coaching practice here and her background here.
Microwaving coconut oil is so much easier. In fact I microwave both the coconut oil and raw honey together, in a glass bowl at a low power, when I make homemade peanut butter. I also use it to reheat foods, once again lower power is key, and it usually takes several times but my food comes out hot not burned or over cooked.
this has been on my mind too. 12 years of bending over backwards to heat up cold food on the stove at home or the millions of long shifts at work where i]d eat cold food because my brain wouldn’t even consider microwaving as an option. i’m opening my mind and have just started considering the microwave. good post, i’ll keep this in mind.
Same here. After more research, I do think it’s an energy-and time-saving option, but I’m using it to reheat/melt food only and not cook anything (gross).
Thanks for this well thought out article!
Ever since my son was born I’ve become ultra conscience of such things and although I’ve read lots about microwaves, the negatives I’ve read haven’t been well researched and so I’ve been on the fence. As you mentioned I only use it for reheating, melting butter and cooking something like oatmeal so thanks for giving me the peice of mind about this topic that I’ve been looking for! 🙂
I also became concerned about the effects of microwaving, but never came across any real proof that microwave ovens are a hazard. This world is full of so many hazards anyway, I’m not sure it’s worth worrying about. They are a great convenience, and save energy and time.
As a former Tupperware consultant, I learned how to cook several things (including chicken) without the rubbery effect. Tupperware makes several great products for microwave cooking and re-heating. They also have some great cookbooks. I’m no longer associated with Tupperware, but plan to buy some additional products soon so I can make own “TV dinners” for lunch at the office.
Thank you for this article to clear up some of the confusion and negativism.
microwave fear is one of my big red-flags for inaccurate health information. The reports of dangers all come from things like microwaving blood for transfusion (kills the live blood cells by overheating them) or microwaving breastmilk (uneven heating can lead to burning baby’s mouth and kills probiotics). For things you would be cooking (not just warming) anyway, there is literally NO danger.
We use ours only to heat things up and for my husband to constantly lose his coffee in.
We made room for our microwave in our garage (which is much more of a storage room than a resting place for our car). I wanted to take more of an ‘out of sight, out of mind’ approach when it came to the microwave. Although I hadn’t cooked in it in years, I still was quick to reheat foods in it purely out of convenience. Now I maybe use it once a week to heat up maple syrup or something. We never had one growing up (my dad still insists that microwaves have contributed to the rise in breast cancer rates). I figure that if I won’t put my chest in front of it, I certainly don’t want my children’s heads in front of it either. 🙂
LOL!! Too true!
Thank you for your willingness to re-examine microwave ovens and their effects! I’ve read article on both sides and still do – often resulting in a good laugh. Thank you for quoting your research sources too – I wish more would do that! I am a retired Electrical Engineer, learned all about microwaves quite some time back, and have been using a microwave oven for several decades. For the record, I would not necessarily trust the FDA. Given that, however, I am confident in my knowledge of physics, wave theory and such. Those tiny holes in the front doors of microwave ovens that allow one to see how things are cooking inside are also a BLOCK to radiation (a bit of an exaggeration, but think, if you will, of peas flying around in there – they won’t fit through those holes!). One “danger” would be if your door did not close and seal properly – and all microwave ovens I am aware of have taken multiple steps to insure that operating with the door ajar cannot happen. No need to stand to the side, although if that makes one feel better, then go for it! Also, if someone actually removed the metal covers to work on it, putting them back on properly is important (but this is unlikely, as most people would junk it and buy a new one when theirs breaks). In our hurry-up society, there is a tendency to use max power and shorter cook times – a trend that leads to cleaning your oven’s interior more often than not. 🙂 Heating an item slowly allows the heat to spread more evenly and with more consistent results (my opinion). Thanks again for dispelling so many myths.
Thanks for your insight and for your thoughtful comment!
I am a little late on commenting but I don’t think microwaves are as dangerous as suspected. I a nuclear engineer in grad school trying to obtain a PhD in this field. I don’t necessarily agree with FDA, but it is true that the type of radiation emitted by microwave is harmless because it is non ionizing so it does not cause damage on out cells. We get more ‘radiation’ by eating a banana with radioactive potassium. The stove heats food by conduction, the oven by convection, and microwave by radiation which is just another type of heat transfer. I agree though that microwaves don’t make foos taste as good can hear things unevenly. So I agree with using it for simple things and sticking to the oven which provides more distributed and even heating.