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Red Microwave Oven

Microwave Ovens, Friend or Foe?

In the last few months, I’ve been delving into my studies with great enthusiasm. Some of it I agree, with, other areas, not so much.  But one area of study has me befuddled.

That area of study has to do with microwave ovens.  Microwave ovens were not part of any household when I was a child. In fact, I remember our first one vividly.  My sister (who is about 15 years older than me) gave my mother one for Christmas one year.  I remember my mother letting it sit for a week before finally using it to make herself a cup of instant coffee.  She was actually a bit scared about using it. I don’t recall her letting my brother or myself use it for quite a while.

But a microwave oven has been an part of my kitchen since I moved out.  I don’t use it for cooking, more for defrosting and reheating, but I’m starting to question that usage as well after reading my book.  Of course for me, I have to go through the research and find out and even there I’m not sure.

Most people are aware of the concept of how microwaves work via electromagnetic energy, heating the cells of the food rather than the container.  One thing that is clear is that government regulation requires that microwave ovens contain the microwaves within them. Even so, the government recommends that people not stand in front of a microwave oven that is on.  I’ve known about this for a long time.  It wasn’t, and still isn’t an issue for me.

But other areas are cause for concern.  Superheating is one area that while annoying, can also be dangerous, and is something I just don’t want to deal with.  I’ve had this happen.  I’ve heated up water in a microwave and began to remove it only to have the water “blow up” in front of me.  To this day, I never heat water in the microwave alone, always with something in it (a tea bag, etc) to not have this happen.  But again, I know this is a possibility and I work around it.

There are dangers when you heat foods in plastic that can then release some of the chemicals.  For safety’s sake, take your food out of your plastic storageware and heat it on microwave safe glass or ceramic.

There are numerous articles about the dangers of heating baby formula in a microwave, specifically since microwaves heat unevenly and what feels at the right temperature to a parent, might be too hot in another non-tested part of the bottle for a baby.

But more important to me is the idea that a microwave might change the substances it heats up. There are a lot of references on the internet (and I did find a reference to the case) about a woman who was in the hospital for hip surgery. She received a transfusion of her own blood. While it is common for blood transfusions to be warmed, they are not warmed using microwave ovens. Apparently someone warmed the blood for the transfusion in a microwave oven and she subsequently died of a blood clot.  The implication is that the microwave changed the blood.  But I can’t find anything definitive on that. There are also some studies cited regarding changes in the chemical structure of the food which were done in both Russia and Switzerland.  While my study book argues that this is definitive, I can’t find corroborating evidence.

The argument is that microwaving food changes the nature of the food and can be cancer causing. The evidence is mixed, and none of the actual studies can be found.

So while I’m not totally convinced that microwaving foods are bad for me, but I’m not totally unconvinced either.  I don’t actually cook with my microwave and if you do, you might want to reconsider.  Most of what I have used a microwave for is reheating foods and for defrosting.

I decided to try to get by without my microwave for a month.  I mostly succeeded, but not totally.  Microwaves make it easy to decide what to have for dinner at the last-minute. If what I wanted for dinner is still in the freezer, I can simply toss it in the microwave to defrost.  Now I need to decide what to make the night before. More forethought and planning. I pretty much managed to not use it for defrosting (but did so a few times when I forgot).  I also stopped heating up the ice tea mix I make.  I’ve begun heating water in a sauce pan instead.

The hardest part has been heating up leftovers.  It’s just so darned easy in a microwave.  Also “zapping” meats that came out a little too rare for my taste.  But other than that I didn’t use my microwave much at all.

While I’m not totally subscribing to the fear mongering, the idea is giving me pause. So I’m not giving up my microwave yet. But I’m not totally sure I’ll replace it when it stops working either.

What do you think about microwaves?


9 Responses to “Should we be using our microwave ovens?”

  1. Cyana says:

    thought provoking, I’ve been right there with you for some time. It’s easy to believe they are evil but hard to find hard facts to substantiate those beliefs. I’ve often thought that I’d like to get two identical house plants and water one with well water and one with well water that has been microwaved and then cooled? Just a thought.

  2. Microwave ovens do their thing via dielectric heating, so any molecules that have a suitable magnetic dipole will start moving faster and thus be hotter. Water is one such molecules, and a lot of microwave heating comes from the water in the foods. Other molecules, such as fats and carbohydrates, are less affected.

    Some plastics are melted by heat, either due to dielectric heating or transmitted heat from food. Containers are usually rated if they microwave safe, so it’s worth checking and avoiding containers that are not so rated.

    Of course heat can have chemical effects as well as physical. Substances that break-down chemically or chemical reactions that are facilitated by heating are of interest. Foods generally change when heated. I would not be surprised if some of those chemical reactions produce unhealthy substances. But the such chemical reactions also occur on a stove, oven, or grill. I would not single-out microwaves.

    • I have to agree, based on my understanding of the physics of microwaves (relatively deep) and the chemistry of heated foods (not as deep). The suggestion not to stand in front of a microwave has some basis in reality; in order to make a transparent front, you must have degraded shielding. By law in the US at least, it still meets basic requirements for protecting what’s outside the heating box of the microwave oven, but the US suggestions are also kowtowing to the only real authority in radiation exposure (the US NRC – http://www.nrc.gov ) within the country, and they have a policy of only being exposed when it’s avoidable (which is understandable for the types of radiation they are primarily concerned with), and while there’s nothing imprudent about following such a suggestion for microwaves, it can be overcautious. I don’t have any fear of standing in front of a microwave while it operates, with my understanding of the physics, but I also haven’t got any good reason to do so.

      To the extent that people use containers with inappropriate materials present for cooking, microwaves are no better nor worse than flame-based or electric heating. “Don’t heat your soup in the can when the can is plastic-lined”, for example. The uneven heating described for microwaves is just as true, though with a typically different heterogeneity profile, for any heated food – stirring is important!

      All that said, I would be interested to read the actual study, for any study suggesting that a dielectric heating method in the radiative frequencies used for microwave heating caused a preferential breakdown of chemicals present in food which is different from other heating methods.

      • Sandra Clark says:

        That’s the problem, I can’t find the actual studies. I can find references to the studies (the mercola article I linked to has them), but nothing on the studies themselves, just second and third party references. And with only second and third party references, I can’t make myself totally believe that the issues exist.

  3. Heidi says:

    I’ve done similar research on microwaves with very similar, befuddling results. On the other hand, I am equally confused about the surfaces of my cookware being safer – or not – than the microwave. I am concerned about possible carcinogenics perhaps in the oven; whether burnt spills being reheated will add unwanted chemical to baked foods, etc. Then, again, are these possible issues being passed on to us when we take part in a potluck, or eating out or making purchases? Perhaps our bodies will eventually evolve enough to adapt to the constant changes in our environment – but I won’t count on that, either.

  4. Keith Campbell says:

    The blood incident doesn’t surprise me, actually. Microwaves, for all practical purposes, heat the water in the food. Extremely dry foods, like crackers, barely heat up at all. And they heat unevenly. So it doesn’t surprise me at all that blood warmed in a microwave wouldn’t warm evenly, and would then clot and clump. (Tempted to try this with beef blood. Bet it would be the same.) I have noticed that, like blood, milk products don’t take well to microwave heating, mostly because of the uneven heat, so I mostly do those on the stove unless I’m just warming the milk up a bit for breadmaking or something.

    I use the microwave to reheat, to heat water (careful of the superboil, of course), and occasionally for vegetables if I’m in a hurry and don’t want to mess with the steamer. Very occasionally to thaw meat. I’m not at all convinced that the microwaves are damaging the food in some fundamental way, but I wouldn’t be surprised if the microwave reduced the nutrient values a bit compared to steaming or whatever.

  5. I have come to call my microwave a food killer. It makes food soggy and gross. I’m not sure about the “conspiracy theories” surrounding microwaves or not; but have moved away from the microwave nonetheless.

    To defrost things; I put them in a zip lock baggie; place them in a big pot and fill the pot with hot water from the sink. 15-30 minutes later; the food is defrosted enough to be cooked. It is not nearly as quick as a microwave; but it is usually suitable for my purposes.

    To re-heat many things–like pizza–I use a toaster oven. For some others, such as chicken or vegetables or Mac and Cheese; I’ll heat them on the stove in a pan w/ some Olive Oil. This usually takes under five minutes.

    The only thing I use a microwave for is to heat milk or water for Hot Chocolate. This is primarily so I don’t have to wash the Kettle.

  6. microwaveguru says:

    I am a microwave scientist and expert in legal cases. IOve been microwaving for over 50 years, own about 50 microwave ovens and done a great deal of research invovling them. Some comments:
    1. Superheating: it is a real problem. I believe I was the first scientist to report on the problem in a reputable journal. My advice is keep a spoon (yes, metal – it has no negative effect – I did the fundamental research in the area) in the cup as you heat the water.
    2. Plastic wrap – this is innocuous unless it melts into the food, but even so it is not dangerous but also not tasty.
    3. Standing in front of a microwave oven is not dangerous – the leakage is so small it is close to zero. Even with the door off you won’t be instantaneously injured. People have an entirely incorrect idea about microwave radiation – all it can do is heat – so, you’ll feel your skin getting warm, so step away. You won’t be instantaneously burned – it is not at all like putting your hand in a flame of extremely hot water, where you can get a serious burn instantaneously. Microwave oven power is generally between 500 and 1000 watts; I’ve put my have inside an industrial microwave oven operating at 10,000 watts – my hand got warm and when it felt uncomfortable I pulled it out – NO INJURY!
    4. Baby food – the warning is correct when it refers to baby food in small jars. It can get extremely hot in the middle for several well-understood reasons in physics. I also did the first reported research on this.
    5. Microwaving a unit of blood plasma – I’ve done a lot of research on this. The woman died because the microwaves heated someplace in the plasma over 98.6 degrees and caused the blood proteins to coagulate – probably in the corner of the blood unit. It has nothing to do with the microwaves themselves – heat the blood plasma to over 100 degrees in a water bath and that will kill a patient.
    6. The claim in Russia and Switzerland that microwaves somehow alter the chemical structure of food is totally erroneous and makes no scientific sense. Microwaves are a form of electromagnetic energy, as are light, TV, radio waves, x-Rays, ultraviolet, etc. All are distinguished by frequency & wavelength, and all have inherent quantum energy content (qec). Looking at it that way, we find that microwave’s qec is on the order of 0.00001 electron volts (ev); visible light: 0.3 – 0.5 ev (so there is about 30,000 to 50,000 times more energy in visible light, and I’m sure you are not worried about that. These are forms of what is known as “non-ionizing” radiation – they are too weak to cause chemical changes. On the other hand ultraviolet (0.5 – 20 ev) and x-rays (20 – 30,000 ev) are forms of “ionizing radiation” and are of high quantum energy: sufficient to break chemical bonds, damage DNA and can cause cancer. Microwaves are simply too weak to do that.
    7. Finally, any form of cooking Boiling, broiling, baking., grilling, etc.) can destroy nutrients by overcooking. Numerous research studies published in peer-reviewed scientific journals all agree that microwaving is the least destructive of nutrients along with steaming and poaching.