Are microwave ovens safe? Do they destroy nutrients?


(Posted on 10-18-11; update on 11-30-11 with input from Dr. Colin Campbell)

What are the best and worst methods of cooking your food? A reader sent me the following note over the weekend:

Are microwaves safe to use? Do they destroy nutrients?

After being referred to your book by Amazon, I did a little research and found your site. I am somewhat puzzled that you would use a microwave to prepare your food. Looking forward to reading more of your articles/blogs and hearing your thoughts on microwaving food once you have a chance to do some research on the topic. Lucinda

Hi Lucinda, After reading your note just now, I decided that if I could run your microwave concerns by just two people, that they would be Dr. T. Colin Campbell and Dr. Michael Greger, both of whom were educated at Cornell. One is a scientist and the other an MD who also has a degree in agriculture.

My first step was visiting Dr. Greger’s new website, nutritionfacts.org. He has been posting a new video every day for about six months and presents extremely well-researched and highly documented information on all aspects of nutrition. From his website, here are his credentials:

Michael Greger, M.D., is a physician, author, and internationally recognized speaker on nutrition, food safety, and public health issues.  A founding member of the American College of Lifestyle Medicine, Dr. Greger is licensed as a general practitioner specializing in clinical nutrition. Currently he serves as the Director of Public Health and Animal Agriculture at the Humane Society of the United States. Dr. Greger is a graduate of the Cornell University School of Agriculture and the Tufts University School of Medicine.

In this 3.5 minute video, Dr. Greger goes into great detail in reporting the relative effectiveness of various sources of cooking. He says that “food scientists outdid themselves last year with a total of 300 experiments aimed at identifying the best cooking methods.” His findings may surprise a few people.

By the way, I would be real surprised if Dr. Greger has totally missed the boat about the dangers of microwave cooking, as he impresses me as being one of the most thorough people I have ever seen. But, just to make sure, I checked a few more sources. (See link to Dr. Greger’s site below)

From Wikipedia: Several studies have shown that if properly used, microwave cooking does not change the nutrient content of foods to a larger extent than conventional heating, and that there is a tendency towards greater retention of many micronutrients with microwaving, probably due to the shorter preparation time. Any form of cooking will destroy some nutrients in food, but the key variables are how much water is used in the cooking, how long the food is cooked, and at what temperature. Nutrients are primarily lost by leaching into cooking water, which tends to make microwave cooking healthier, given the shorter cooking times it required. 

According to Wikipedia, the microwave might be the very best way to cook spinach.

Spinach retains nearly all its folate when cooked in a microwave; in comparison, it loses about 77% when cooked on a stove, because food on a stove is typically boiled, leaching out nutrients. Microwave blanching is 3-4 times more effective than boiled water blanching in the retaining of the water-soluble vitamins folic acid, thiamin and riboflavin, with the exception of ascorbic acid, of which 28.8% is lost (vs. 16% with boiled water blanching).

I also read a few of the Mike Adams’ articles (that you recommended) but could not find much about his educational credentials on his various websites. Further, I will run the question by Dr. T. Colin Campbell the next time I speak with him. But for now, I have not been convinced to stop using my microwave. Here is that Campbell report:

11-30-11. On November 21, a colleague and I met with Dr. T. Colin Campbell in his home office. While breaking for lunch, I noticed a microwave in his kitchen and asked if he ever uses it. He said rarely. But not because of any scientific evidence. He told me he saw a series of pictures comparing two plants, one watered with fresh water; the other with water that had been microwaved. I remember seeing those pictures and they were quite dramatic.

Even though he has no scientific proof of anything, he said that since seeing those pictures, he has tried to steer away from the microwave. But he’s got an edge on me. He is married to Karen over fifty years AND she was preparing his meals for him for more than twenty years before microwaves.

As for me; at least half of my calories are raw, 40% cooked conventionally (home and restaurants) and about 10 percent in the microwave. It would be very inconvenient for me not to use it for conventionally cooked foods that I warm up before eating. And I like the convenience of using it for popcorn.

Authors J. Stanfield Hicks and J. Morris Hicks , working daily to promote health, hope and harmony on planet Earth. Shown here at age 33 and 61 respectively.

On a personal note, my health is far superior now that I have been eating mostly whole plants for almost nine years. I used microwaves before the change and still do, so guess I’m still getting plenty of the nutrients that I need.

In the future, when people ask me about the nutritional hazards of using microwaves, I will refer them to this blog.

Dr. Greger’s website at nutritionfacts.org

Microwave oven – Wikipedia, the free encyclopedia.

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About J. Morris Hicks

A former strategic management consultant and senior corporate executive with Ralph Lauren in New York, J. Morris Hicks has always focused on the "big picture" when analyzing any issue. In 2002, after becoming curious about our "optimal diet," he began a study of what we eat from a global perspective ---- discovering many startling issues and opportunities along the way. In addition to an MBA and a BS in Industrial Engineering, he holds a certificate in plant-based nutrition from the T. Colin Campbell Center for Nutrition Studies, where he has also been a member of the board of directors since 2012. Having concluded that our food choices hold the key to the sustainability of our civilization, he has made this his #1 priority---exploring all avenues for influencing humans everywhere to move back to the natural plant-based diet for our species.
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6 Responses to Are microwave ovens safe? Do they destroy nutrients?

  1. tokyovegan says:

    As a plant-based eater who relies on microwave for making my morning soymilk latte to steaming vegetables, and reheating everything from soup and potatoes to grains and pasta, I would be very interested to hear Dr. Campbell’s thoughts about microwave cooking, as his “The China Study” single-handedly motivated me to adopt a plant-based diet. I also rely heavily on Dr. Greger’s nutritionfacts.org and was encouraged to discover his favorable assessment of microwave cooking methods. Recently, I have been learning a lot about macrobiotics, which claims microwave cooking destroys food, and the waves are hazardous to humans. Why is it that we were warned about sitting too close to the TV as children, but microwaves are considered safe by 99 percent of the population? Could it be because cell phones, wifi, etc, are hazardous, too?

  2. Mitzi says:

    Mercola and Mike Adams are not physicists, biochemists, or chemists. I have worked with all of the above in taking classes or assisting in laboratories. All of them use microwave ovens to heat their food, and to warm solutions quickly in the lab. Microwaves are simply one of many ways (and a pretty energy-efficient way) to heat things. How else are you going to get your lunch heated in 1 minute 30 seconds, and be back in the lab quickly to finish experiments?

  3. cacatua21 says:

    I’m not going to take you to task for using microwaves. I’ve never considered them to be evil, but they do work better for some things than others in my experience. I cook things in them that work well, like brussels sprouts, cauliflower and broccoli in covered cassaroles with very little added water, and thaw or reheat things. I like to roast vegetables like the onion-potato-carrot combination, or beets in the oven for really good flavor. It takes longer but I put them in a covered cassarole and use no water, or wrap the beets in foil. This time of year there are good squash to roast too. I also have some good heavy non-stick aluminum saute’ pans in which I fry (?) things like chunks of sweet potato, carrots and parsnips, with or without a little added water to begin with, until they are browned some and done. I don’t use oil with any of these.

  4. Jason says:

    You focused on nutrients being retained, but avoided all the carcinogens being added. There is a lot of information regarding that out there too. If a plant based diet is so obviously natural to you, how can you imagine a microwave oven cooking things in 30 seconds is natural and healthy? Is it not possible that there are long term negative effects of using a microwave that your current superior health is masking? I could say I switched to eating a steak every morning for 20 years and feel great, only to have it all catch up to me and get sick 30 years from now. I just think it’s worth investigating further.

    • jmorrishicks says:

      Thanks for your comment. I will continue to keep an open mind and will poll other noted experts in the field. If I find compelling evidence to the contrary, I will amend this post (or replace it) accordingly.

      As you may know, I am not an expert in “all things food,” I am just somewhat of an expert in the “big picture” of how the diet-style in the Western world is destroying our health and our planet and that is totally unsustainable for much longer.

      I see my role more as one of an activist to help change all of the above, not an expert on things as to how we should cook our meals, what percent should be raw, etc. Thanks again for your comment. Be well, J. Morris Hicks

  5. Bea says:

    Hi,
    Having read the above, I have decided that I would end my subscription to your blog. Microwaves ARE DEADLY. Please do more research, and if you would go back to Natural News, you will find there enough articles written by enough people telling you just that.
    Another good site is the one from Dr. Mercola. And there are many more if you were but willing to do some more research. Simply “google” microwave and you will find out about this.
    Two searches are not enough !!!!!!

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