Does Microwaving Destroy Nutrients? Not Always

Does Microwaving Destroy Nutrients?

Lately I have been hearing and reading about the idea that microwave ovens destroy the nutrients in our foods.

And I have even heard that microwaving can be outright dangerous.

So I thought this might be an important topic to investigate.

Well, I have some news for you…

It turns out that microwaving your food does not destroy nutrients, in fact it demonstrates equal or better retention of nutrients as compared to other cooking methods…1

For example, studies at Cornell University found that spinach retained nearly all its folate when cooked in a microwave, but lost about 77 percent when cooked on a stove.2

A meta-analysis of the microwave nutrient issue published by the The Journal of The American Dietetic Association concluded that:

…studies showed equal or better retention of nutrients for microwave, as compared with conventional, reheated foods for thiamin, riboflavin, pyridoxine, folic acid, and ascorbic acid.”

They also found that that bacon cooked in the microwave has significantly lower levels of cancer-causing nitrosamines than conventionally cooked bacon.

The Science of Nutrients and Cooking

The first fact to know is that every method of cooking can destroy nutrients.

Steaming is a great way to preserve nutrients in food

The main issues to consider are:

  • Cooking Time: The less the better
  • Amount of Liquid Used: The less the better
  • Cooking Intensity: The lower the better

With microwave ovens, cooking times can be so fast that they actually use less heat (intensity) than most other cooking methods.

By using low heat, microwaves can help preserve the most heat sensitive nutrients like B & C vitamins and folic acid.

And as already mentioned, microwave cooking times are shorter than almost all conventional methods.

One of the biggest nutrient-draining cooking methods seems to be boiling because of the submersion in excess water. 3

In a study involving broccoli, between 74% and 97% of nutrients were lost when water was added to the cooking method, while when steamed or cooked without water very few nutrients were lost.

How to Cook Using The Microwave

(This advice actually applies to non-microwave cooking as well.)

First, make sure not to add additional water. For example, after you rinse your vegetables off, make sure to dry them off with a towel before putting them in the microwave.

Second, cook as little as possible. As with any cooking method, it is best to undercook as opposed to overcook.

Third, try steaming. There are a lot of frozen vegetable that come in bags you can plop in the microwave and steam.

I hope you have enjoyed this information, and please share your thoughts on this subject below. I know there are plenty of strong opinions on the subject.

Dr. Steven Sisskind, M.D.
Dr. Steven Sisskind, M.D.

1. Hoffman CJ, Zabik ME p. Effects of microwave cooking/reheating on nutrients and food systems: a review of recent studies. J Am Diet Assoc. 1985 Aug;85(8):922-6.

2. http://www.nytimes.com/2006/10/17/health/17real.html

3. F Vallejo, FA Tomas-Barberan, C Garcia-Viguera. Phenolic compound contents in edible parts of broccoli inflorescences after domestic cooking. Journal of the Science of Food and Agriculture 2003 Nov; 83(14):1511- 1516

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12 comments

  1. I had a close friend of mine stop using a microwave because she had really bad IBS. Once she was away from using this appliance her symptoms immediately lessened. Thoughts?

    • Dr. Steve Sisskind

      Hi Cindy,

      Thank you for writing in and for sharing your friend’s experience with us! I cannot say for certain if the microwave itself has caused your friend’s IBS as there are many triggers and other conditions at play. Several factors such as antibiotic therapy, a decreased ability to digest dietary fibers or a sensitive stomach– form example, can all cause a form of Irritable Bowel Syndrome. However, I am glad she is all better now and able to continue her journey to better health. Make it a healthy day!

  2. Are you being paid to advertise for microwave companies????? Your comments are totally opposite of what we’ve been taught for many years. We were told over 30 years ago to never heat a baby bottle or breast milk in the microwave because there could be a loss of vitamins and some protective properties were lost by microwaving. If that is so important for an infant, why doesn’t it apply to adults heating food in the microwave also?
    Dr Mercola has shared some test results: “Significant changes were discovered in the blood of the volunteers who consumed foods cooked in the microwave oven. These changes included a decrease in all hemoglobin values and cholesterol values, especially the HDL (good cholesterol) and LDL (bad cholesterol) values and ratio.”
    I think you need to look at some additional resources for your information.

    • Dr. Steve Sisskind

      Hi Lavonne,

      Thank you for writing in and for sharing your thoughts with us! I am deeply sorry for the impression that was given by the article but wanted to reassure you that I am not compensated for it. A lot of change has taken place in both the production of microwaves as well as the safety standards used to check them over the past 30 years. They are a lot safer now and the energy given off is only meant to excite water molecules. I am curious about the article you mentioned and may have to read up on that. I hope you continue to stay tuned with my future posts as I may release an update on this present topic. Hope this helps! Make it a healthy day!

  3. Your references seem a little out of date.

    • Hi Jane,

      Thank you for writing in and for sharing your thoughts with us! I am very sorry that the references seem a little out of date. They were the main references used when the article was published. I’ll be sure to share new ones on the next blog post! Make it a healthy day!

  4. My doctor said that the microwaves altered the protein structure. I notice the studies cited didn’t delve into this aspect….

    • Hi D. Leightner,

      Thank you for writing in and for sharing your concerns with us! Yes, applying heat, in any form will certainly change the bonds of protein in your meat. This reaction will breakdown the structure and make it easier to digest. However, if you mean that the radiant energy from microwave cooking will alter the protein in such a way to cause us harm, then no. The radiant energy in your microwave is only enough to excite the water molecules which produces the heat in this reaction. Modern day microwave ovens undergo rigid testing and have to constantly meet safety standards to ensure that they are safe for every day use. Hope this helps! Have a healthy day!

  5. Interesting article about the nutrient content of microwaved food.
    I’ve also read that it changes the structure of the food and creates free radicals. That would be equally as important to me. I wonder if you could comment on this.

    • Hi Ken,

      Thank you for writing in and for sharing your concerns with us! Microwave cooking does change the structure of food, to a degree, because it applies heat to your proteins, fats and carbohydrates. Microwave ovens are designed to emit heat by exciting molecules and this friction causes the temperature to rise. As soon as the radiant energy is cut-off, the molecules are no longer excited and the reaction stops. Free radicals are produced when there is an introduction of a molecule and a chemical reaction takes place. This does not happen in the microwave, otherwise, your water would turn into Hydrogen and Oxygen when heated in the microwave. Hope this helps! Make it a healthy day!

  6. One hears a lot of warnings about using plastic pouches and dishes in a micro. I never use those supplied by a food mfr. What IS the current info. on plastics in a micro. One never knows the chemical makeup of ‘things’ anyway nor any reaction under heat. ???

    • Dr. Steve Sisskind

      Hi Gary,

      Thank you for writing in and for sharing your concerns with us! There are microwave “safe” dishes and plastics you can use for heating in your microwave oven. Be sure to look for the microwave safe logo, usually located at the bottom of the container before making your purchase. These dishes do not react to the waves of energy given off by the appliance and can stand up to the heat made in the process. Hope this helps! Have a healthy day!

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