Marks Daily Apple
Serving up health and fitness insights (daily, of course) with a side of irreverence.
18 Mar

Are Microwave Ovens Safe?

MicrowaveTo Nuke or Not to Nuke?

The verb itself suggests the unleashing of atomic destruction, but we wondered, “Is there a grain of truth behind the slang?” What’s the real story behind these boxes of convenience sitting in so many of our kitchens? Are microwaves a benign bastion of modern handiness or, as some claim, a sinister contributor to our physiological (at least nutritional) undoing?

It’s likely that we find ourselves in a variety of camps on this issue. Some of us swear them off. Others unapologetically swear by them to get through the normal course of a busy day. And then there are those of us in the dithering middle who routinely stare at each plate of leftovers or bowl of frozen vegetables, sometimes reaching for the pots and pans and other times giving into convenience but always questioning whether we’re paying for it.

Should we be plagued by these pangs of conscience? Are we emitting dangerous radiation into our homes or killing off the nutritional value of our unsuspecting food? Are we making a mountain out of a molehill? What should we believe? Is there enough evidence to really tell either way?

We definitely know this much. Grok didn’t have a microwave. But, then again, he didn’t have a jet shower, Bose stereo system, or Hammacher Schlemmer thumper massager. (Trade-offs, you know…) As much as we love Grok and think his era has been unduly disparaged, we aren’t arguing that he had the best life possible or that anything he didn’t have isn’t worth having. Nonetheless, while it’s a naturalistic fallacy to assume that everything post-Paleo is an abomination, it’s both fair and reasonable to question the safety of today’s customary appliances.

Here’s what we found. First, to the question of transforming your home into a radiation zone… There is, not surprisingly, disagreement about this point. However, occasional home use of a fully functional microwave appliance is generally considered safe. Microwaves do, make no mistake, emit radiation, and the FDA has established what it considers “safe” levels for microwaves: over the machine’s “lifetime” the allowable level is “5 milliwatts of microwave radiation per square centimeter…approximately 2 inches from the oven surface.” Guidelines from the International Radiation Protection Association (IRPA) suggest overall radiation limits of 1 milliwatt per square centimeter “averaged over 6 minutes (0.1 h) period.” Unless you’re using your microwave on a perpetual basis, there’s little reason to worry.) Because the radiation diminishes quickly over distance, standing further away from the microwave during operation cuts your exposure even more significantly. (That instinct to not press your face against the glass door while your lunch was cooking turns out to be right after all…) Additionally, the FDA requires two interlock systems that effectively offer backup security as well as a monitoring system that shuts the microwave down if one of the systems isn’t working or if the door is opened during operation. Common sense adds that you might want to make sure the microwave seal isn’t compromised by built up tomato sauce or other grime. (Hmmm…anyone?) And, of course, it’s a good idea to replace an old, dilapidated microwave even if it’s a great conversation piece. Safety versus vintage flare…

And now for the more common question. What about the nutrients? (We should mention quickly that microwaving of food isn’t the same as food irradiation, which involves a higher level of energy and is considered much more damaging in terms of “complex chemical changes … in food components.”) But how do nutrients fare behind the closed, latched, double interlock system door? Well, it varies. As we’ve reported in the past, cooking of any kind can sometimes reduce the nutritional value of food and occasionally enhance it. Slow and low are typically the way to go with cooking, as we’ve said. A pretty much universal concept for our friends, fruits and veggies: steaming or cooking/microwaving with small bits of water trumps boiling or deep frying. When it comes to microwaving itself, studies suggest some mixed reviews for individual vegetables or nutrients but indicate, overall, that microwaving generally preserves nutrient levels.  One study using Brassica vegetables found that microwaving resulted in comparable nutrient (glucosinolates, a possible cancer preventative compound) loss when compared to steaming or stir frying.  (Actually, shredding the vegetable ahead of time had more impact on nutritional value than the cooking method.) However, another study using broccoli suggests that antioxidants can be significantly depleted.  (Antioxidants, particularly water soluble vitamins, appear to be most at risk while minerals tend to be generally preserved in microwave preparation.) Yet another study review showed that microwaving with low power settings offered “equal or better retention of nutrients … as compared with conventional, reheated foods for thiamin, riboflavin, pyridoxine, folacin, and ascorbic acid.” University of Illinois research also showed that microwave blanching (brief exposure to high heat used for pre-freezing preparation to lengthen storage ability of frozen produce) was as or more successful in retaining nutritional value than conventional blanching methods. (Nonetheless, blanching does diminish nutrient levels.)

But how could microwaving actually preserve more nutrients in many cases? Not only do we generally use less liquid when cooking in the microwave, cooking times are typically shorter than those for conventional cooking. (As a side note, new ceramic cookware designed for microwave use shows promise to cut cook times further still, which can mean even greater nutrient preservation.)

Our best advice: nuke wisely. If the convenience of a microwave keeps you committed to PB eating, use it as you need to. (We’re all for leftovers, freezing fresh produce to save money, etc.) Nonetheless, thinking outside the micro box is likely a good idea as well. Invest in some small pans for single servings or small cooking jobs. (If it takes up less space in the dishwasher/sink, it seems like less of a chore.) And, of course, avoid heating (and especially reheating) whenever you can to retain the most nutrition. Heat only the ingredients you must to make a dish palatable, and keep water use, time and temp (power level) as low as possible. (Bonus: it helps you avoid those nasty steam burns from handling overheated dishes.)

Have your own reasons for yea or nay on nuking? Let us know what you think and any tricks you’ve found useful to avoid or minimize microwaving.

limonada Flickr Photo (CC)

Further Reading:

Should I Stop Eating Flax Seed?

8 Ways to Reduce Your Chemical Load

What’s Wrong with Juicing?

You want comments? We got comments:

Imagine you’re George Clooney. Take a moment to admire your grooming and wit. Okay, now imagine someone walks up to you and asks, “What’s your name?” You say, “I’m George Clooney.” Or maybe you say, “I’m the Clooninator!” You don’t say “I’m George of George Clooney Sells Movies Blog” and you certainly don’t say, “I’m Clooney Weight Loss Plan”. So while spam is technically meat, it ain’t anywhere near Primal. Please nickname yourself something your friends would call you.

  1. It seems obvious why microwaved food is bland or tastes wrong to many, especially the foodies: the whole olfactory experience of stovetop cooking is missing. Many people just love the entire cooking experience, and spend as much time as they can justify stirring and sauteing the food, just to wallow in the olfactory bliss of it all.
    I’m the opposite. Maybe because my nose seems much more sensitive to bad odors than pleasant ones, I don’t get a big charge out of food preparation. I just want to get it cooked as fast as possible so I can cram it down my gullet. My taste buds are sensitive enough, and I don’t find anything wrong with microwaved food. But then again, I’m not the type of person who can detect overtones of sage, fennel, or apricot in my Moscato, either (lol.)

    BillP wrote on May 6th, 2013
  2. Secrets of Cast Iron Cooking (Reheating) over Microwave!

    First off, when I breastfed my two boys for 3 1/2 years back in 1973, and had to fight off the wrath of doctors, nurses and hospitals, I learned that the mother carrying the child and the breast milk she produces needs “iron!” I now see why my Polish-American Mama used to force liver down my throat. I read cooking with cast ‘iron’ retains the iron content better. Although I’m not obsessive about anything I do, but I do not shop the inner aisles of the grocery store.

    I heard from a man from Hungary who said he threw his microwave out. He said in Hungary, (where he travels back and forth to and from) the people don’t use them. He mentioned a study that said that water that was microwaved was used to water plants and the plants either died or did not grow. But this is “hearsay.” I also heard that Russia banned then in the 1970’s and Germany who was supposed to have invented them doesn’t use them also. This is info from my ancestor lands. I did read on internet just a few days ago a study that thought they were dangerous and also relayed that Russia, Germany and Switzerland does not use them. If people have evidence to the contrary, I’d like to know.

    Since I took gourmet cooking classes in Chicago at one of the finest chef school, (the way to a man’s heart is through his stomach I always heard) I really love the Jenn Air stove top with 5 burners, regular 40 year old oven in the wall, and warming drawer. I cannot do any canning on it as I used to do when married to my US Marine Purple Heart and pioneered organic gardening comeback in 1970 and had so many tomatoes, 50 quarts of Beefsteaks were the average for the year. You can’t even imagine how good spaghetti sauce tastes until you have tried Beefsteak tomato sauce, homemade and cooked just hours after picking. By the way, just as a “jumpcut” a phrase Hollywood uses in movies to change topic suddenly for a moment, when growing organic corn and cooking it the best way is to test the corn for milk by opening slightly and pricking with finger for milky stage, run back to house to heat up water, back to corn stalk and break off corn, run back to house to put into the really hot water, and cook for several minutes. There is nothing sweeter nor more delicious and I would even cook and feed some to neighbors just to be nice for they will never be able to try such a delicacy in their lives.

    I enjoyed this Nu-Wave oven but lifting the heavy top seemed to aggravate a sore painful shoulder problem. But the food was even better than when I first made it. I used it for toast and whipping out a frozen pork chop or even steak, fish, and it bakes right through and tastes great…. But…. I discovered something even greater just recently….

    A cast iron large frying pan from Walmart for about $12.00. When my deceased husband and I would vacation, we’d go camping back in 1970. He was Scottish ancestry and I grew up poor Polish American so we saved our pennies. Since he lived off the land in Viet Nam, he knew how to start fires from wood he chopped off, and when he cooked over a fire dug in a hole like our cavemen, women and children ancestors, everything tasted delicious. It was especially great eating outdoors, by a river for fresh air, and cozying up in the tent late at night after a fine meal, sometime even fresh caught fish. But it was thru camping that I discovered cast iron pots.

    Before I only used it for making homemade honeyed cornbread, or on occasion I slice potatoes really thin and fry up. (I know it is wrong but it is one sin I indulge in especially since I have 4 feet organic potato plants growing in 3 stacked tires painted white and filled with straw so potatoes not only grow underground but (I’m hoping) will grow in the 3 feet of straw filling the tires.)

    Just two weeks ago, I was in a hurry and since I don’t have a microwave I placed my entire dinner meal into the cast iron pan which I put water in first. Perhaps 1/2 cup. The meal was frozen so I had to put a glass dome lid which I lined with water on top inside also. It cooked up quickly and I had to break it apart with fork. I took lid off and then let the water evaporate into just a little bit of sauce.

    I have to say of everything I have tried the food is sooooo delicious, my mouth waters just thinking of the next time I can use it for reheating meals.

    Well, since I’m in hot desert in Las Vegas, I thought I’d get a microwave/convection for I’ve been cooking constantly without going to restaurants for 46 years. My Viet Vet and I never went to a restaurant nor did my kids ever eat Mc Donald’s. All was homemade, organic food, home baked goods even for our 52 German Shepherd prized pedigreed puppies and their parents would get leftovers. I did it out of “love” for I was always looking for ways to keep them at their “highest” level. Before my husband died, the VA hospital said if he hadn’t married me with our changed lifestyle, he would have been dead within a just a few years from Viet Nam as many of his buddies.

    When I looked up microwave/convection a consumer reporting agency said the food does not taste as good, period. Also one has to find a separate line for fear of fires, which I was able to locate a 20 volt line I could use by itself. I’m not happy with something prone to fires, since I once ran thru smoke and hair was singed by flames saving a tenants baby from a blazing fire.

    I had a TV dinner and decided to try out the white shiny microwave. The taste was pretty awful, nowhere near the cast iron invention I wrote above. I’m taking it back even though I great a great bargain. But I’m still debating if I should keep it for emergencies. I don’t drink coffee or tea to warm up water for the hot drinks seem to bother me now and gave up caffeine a long time ago.

    A woman gave me a cast iron pot and she and her husband were 94 year old doctors. I think doctors “keep secrets” from us so they can keep us as steady revolving door patients, even unto the next generation with baby formula, etc. they share secrets among themselves, but advocate a different life style for us. Read the book, “Confessions of a Medical Heretic.” The author’s mentor in acknowledgement is the doctor who delivered my home-birthed, without drugs, 10 pound baby in 1979. Even when the suspicious government agent came to check me and the baby she was shocked to see him rated 10-10-10.

    Barbara Ann Nowak wrote on June 24th, 2013
  3. I’ve been cooking with ONLY Microwave Oven’s, for over 35 years.
    -That’s daily.
    I’m in good health and great shape, at 58. I work in construction.
    I’ve been meat based,paleo, all that time.

    For what its worth.

    Mac wrote on March 26th, 2014
  4. Food cooked in the microwave is different, whether it is safe or not.
    Bread left in a toaster too long will burn, where in a microwave oven if heated too long will turn into something that resembles a rock. :)

    charles wrote on December 21st, 2014

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