Is Microwave Radiation Harmful?

by Alejandra "Alex" Ruani — Get free science updates here.
Photo Credit: Pixabay

Photo Credit: Pixabay

Have you ever been worried about using your microwave oven because you’ve heard that it may harm you in some way? Or that it may destroy the micronutrients in your food? Or even cause cancer?

Are these myths? Are we worrying about nothing? Or is there some truth to these?

Don’t worry. By the end of this article, we will have addressed each of these concerns.

Do microwaves destroy beneficial nutrients?

Microwave ovens have been becoming increasingly popular since the 1960’s, due to their convenience, high energy efficiency, rapid processing time and ease of use.

Researchers have since been investigating how microwaving foods may influence their nutrient content, in a good way OR a bad way.

In a study published in The Journal of Agricultural and Food Chemistry in 2007, it was found that broccoli retained all of its minerals when microwaved but lost vitamin C, which leached into the added water.

Does this mean that we should avoid microwaving our vegetables?

Not necessarily.

Firstly, vitamin C is quite volatile in heat, so cooking in general causes its loss. Luckily, C is plentiful in raw fruits and vegetables, so you can compensate there.

Now, here’s the most interesting part: microwave cooking has been shown to produce the lowest antioxidant losses in 20 vegetables when compared to pressure-cooking, boiling or frying. That’s really good news.

What about omega 3 in fish?

A 2008 study, published in Food and Bioproducts Processing, investigated the effects of different cooking methods on the nutrient content of seabass. Losses of omega 3 fats were higher in the microwaved seabass than in the fried seabass. However, the researchers agreed that the fried seabass added unwanted fats into the mix and wasn’t as healthy as microwave cooking!

When it comes to choosing a cooking method, it really comes down to you (or your client), your personal goals, which nutrients you want to get more of, and which ones you’re trying to avoid! Click HERE to learn more about this.

Are microwave containers risky?

As I’m sure you’ve heard, concerns have also been raised about the use of plastic containers when microwaving food.

When food is wrapped in plastic or placed in a plastic container and microwaved, chemicals from the plastic can leak into the food.

This seems to be causing a lot of worry for people but, according to the Harvard Medical School, this is closely regulated: tests are conducted to ensure that unsafe amounts do not leach into foods and only containers that pass this test can state that they are approved for use in microwave ovens.

On the other hand, the organisation Breast Cancer UK urges the authorities to ban BPA, a type of plastic not only used in microwave ovenware but also in most packaged products! So, if you’re concerned about these risks, switch to the safest alternatives, such as glass and porcelain containers for microwave cooking.

Does microwave radiation make foods radioactive?

Perhaps the biggest health scare out there is inflicted by those who claim that microwaves emit ‘harmful’ radiation, turning innocent food compounds into radioactive substances capable of causing cancer.

But is this true?

These claims are so worrying that it’s worth getting into the nitty gritty of microwave radiation.

What is radiation?

Have you ever thought about what radiation actually is?

Radiation can be found all around us, in varying amounts. It is essentially the release of energy, which is given off by everyday things, such as the sun and household electrical appliances.

We are always being exposed to natural background radiation. From radioactive gases given off from the earth, to radioactive substances in the soil.

Have you ever had an x-ray? That’s another form of radiation.

Ever used a sunbed? Also radiation.

Your mobile phone gives off radiation, as do computers, heaters, and radios. It’s everywhere!

So does this mean that we are in constant danger from microwaves and the world around us? Let’s investigate.

Firstly, it is important to understand how a microwave works.

How do microwaves work?

Before we talk about how microwaves heat your food, let’s make a distinction between two very different kinds of radiation:
1. ionising radiation, and
2. non-ionising radiation.

Ionising radiation, which can remove tightly-bound electrons from atoms, causing them to become charged, is less risky in very tiny amounts (such as x-rays) but can cause problems when exposure is high (think burns and even DNA damage).

However, microwaves emit non-ionising radiation; a type of radiation that has enough energy to move atoms around within a molecule but not enough to remove electrons.

What does this mean?

Because the radiation from microwaves is non-ionising, it can only cause molecules in the food to move. This is good! In other words, microwave radiation cannot alter the chemical structure of food components.

More precisely, when heating food in a microwave, the radiation that the microwave produces is actually absorbed by the water molecules in the food. This energy causes the water molecules to vibrate, generating heat through this (harmless) friction, which cooks the food.

This mechanism is what makes microwaves much faster at heating food than other methods. Its energy immediately reaches molecules that are about an inch below the outer surface of the food, whereas heat from other cooking methods moves into food gradually via conduction, like the bottom of a saucepan directly touching a hot hob ring.

So, is microwave radiation harmful?

Some say that the energy given off by microwaves is enough to damage one’s genetics (DNA) and subsequently cause cancer.

But is there any good evidence to support this theory?

Several studies have been carried out using laboratory animals and in-vitro systems (outside of a living organism) but few have studied living, human tissue so it is difficult to find causal associations.

In 1997, Peter Valberg reviewed all of the epidemiological studies at the time, which looked at the incidence and distribution of cancer in relation to microwave radiation exposure and tried to determine whether microwaves increased the risk of cancer in humans.

He found very little evidence to support a causal relationship between this exposure and disease and, whilst considering what else was known about the mechanism that microwaves use, as well as what had been observed in animal studies, he concluded that microwaves do not cause cancer.

This makes sense because we know that the non-ionising radiation used in microwave ovens is not powerful enough to transfer radiation into food; it can only cause the water molecules to move.

Very few scientific studies have taken place since Valger’s review.

Having said that, a 2011 study, printed in Molecular and Cellular Biology, found that microwave radiation exposure did not show any signs of increased cancer risk in Swiss albino mice.

Today, Cancer Research UK, a world-leading cancer research organisation, tell us that it’s perfectly safe to use microwaves. They also say that as long as you follow a microwave’s instructions for use, it will not cause you any harm.

A huge relief, wouldn’t you say?

What have we learned?

Essentially, microwaves don’t make foods radioactive. They just heat them!

It has never been proven that microwaves cause any harm to those who use them and therefore you shouldn’t worry every time you want to heat up that pot of soup or those leftover baked beans, as long as you follow the instructions of use that came with your microwave.

Do you often cook your food in a microwave? Were you worried before? Has this article reassured you? We’d love to hear from you in the comments below!

And if you’re itching to tell someone how microwaves work, please share this and give them some peace of mind!


Every other Thursday we share our research and actionable advice to help you and those you care about. If you enjoyed this, join our FREE updates.


  • Sabrina Girard

    Reply Reply October 1, 2014

    All I can say is – wow and thankyou!!! You answered all the myths and put me at ease with my concerns. It was very interesting and surprising to be honest, I have never owned a microwave because of all the concerns I’ve had. which you put to rest with this article. I won’t be rushing out to buy one but it’s great information to be armed with.

    • Alex

      Reply Reply October 1, 2014

      Sabrina – glad I could help! And thanks for your beautiful comments on the starter course :-)

    • Melanie

      Reply Reply October 3, 2014

      I normally use microwave to warm up my cold food. I use microwave to cook a sweetcorn for 4 minutes instead of boiling one cob for 25 minutes on the hob.

      I don’t use microwave for cooking because it loses its moisture and becomes dry and rubbery texture. I prefer to use the steamer to keep its moisture and colour.

  • Himanshu

    Reply Reply October 1, 2014

    Thank you so much for the detailed info. Article was beautifully designed with scientific information which was supported by facts from various research organisations. Microwave is a necessary part of the modern lifestyle. And for myself, i mostly use it for reheating than for cooking. So it’s great to receive this information. And to know that there is no danger :)
    But One thing i would like to add is as you mentioned that food may loose some of the vitamins. So depends upon your personal goal, you can choose a cooking method…Do you have any further reference where the detailed information of what is been lost in Microwave and whats not is provided. It would be good to know and if we know that we would be able to decide accordingly.

    I recently joined The Healthsciences group and so far have received some great information. Will look forward for the great articles in future from you.
    Thanks again !!!!

  • Laura

    Reply Reply October 2, 2014

    Great reading!! Thanks for the info. This was something that has always been in the back of my mind, but I never took it too seriously. Now I can continue to microwave in peace

  • sheralyn

    Reply Reply October 2, 2014

    This information about microwaves given is really very helpful. The word radiation often scares people. But to know what is harmful and what is not it very reassuring. Microwave is just not used at homes. They are widely used in restaurants, cafes,etc. So its very difficult to dodge it’s usage. Thank you for giving such useful information. When people are told about radiation from mobile and reduce its usage. Nobody will compare that to olden days when mobile didn’t exists. But microwave existence and usage will always be questioned.
    I am happy with the information passed on to me and will surely forward it to all my friends. Thank you once again.

  • Jo Smith

    Reply Reply October 2, 2014

    That’s so interesting. I am relieved for all the years I have used a microwave but still sceptical about what we still don’t know. Although not scientific I once attended a lecture about dowsing of all kinds and for many uses including geopathic stress. One of the demo’s was on food before and after being microwaved. Before energy from the food made the dowsing tool react vigorously. A couple of other sceptics had a go too. Same result. After microwaving, there was nothing. No movement. Ostensibly it was “dead” devoid of any energy at all. This was several years ago and has worried me far more than radiation as I felt sure that would be strictly monitored. Try it. I will too. Would love to hear what people find/think?

  • Ciara mitchelll

    Reply Reply October 2, 2014

    Fantastic article, had put to bed my confusion about microwaves, cheers

  • Azhar

    Reply Reply October 2, 2014

    Hi Alex
    It’s a very useful article for me because I do not know about about atom theory thanks for such a great knowledge for everyday use

  • Sophie

    Reply Reply October 2, 2014

    I think this article gives a very comprehensive overview of the evidence surrounding this controversial topic and the conclusion that has been made is appropriate. I will not certainly not be worrying about using my microwave any more – thank you!

  • Louisa

    Reply Reply October 2, 2014

    Thank you for the science on the matter! I was brought up in a house without a microwave because my parents thought they are dangerous and unhealthy. I did some research myself a while ago and decided they were wrong, this article helps me reinforce my own opinion that microwaves are safe. I use a microwave every morning for my oats with berries, I am glad to hear that I am not damaging any nutrients in my food by doing this. Thank you!

  • Therese

    Reply Reply October 2, 2014

    Thank you so much! I have been trying to research this for years but found very little information that made sense. Still do not think microwaves should be used for cooking, but so handy to heat up leftovers and defrost foods.

  • Maxine

    Reply Reply October 2, 2014

    I don’t use a microwave due to thinking they are bad but after reading my e-mail this morning I would consider using one again..thank you.

  • Gabriella

    Reply Reply October 2, 2014

    this was such an informative newsletter thank you so much for bringing light to some of the topics that I’ve always been concerned about.

  • Christine

    Reply Reply October 2, 2014

    Thank you for this. The last school I went to preached against microwaves but never, in my opinion, gave solid evidence against it. I try to avoid microwaves but my kids use them. A little more reassuring

  • Susan

    Reply Reply October 2, 2014

    I have definitely cut down the amount that I use a microwave, but I find it very difficult to imagine surviving without it — a reflection on our current society! This article was very interesting, and has relieved me of the guilt I carry every time I do use the microwave. Thank you!

  • Kelly Joanis

    Reply Reply October 2, 2014

    This was an excellent description of radiation and makes perfect sense. I am a Radiation Therapist working with ionizing radiation and get questions all the time if the patient is radioactive after a treatment.

  • K. Hill

    Reply Reply October 2, 2014

    Great Article. Information I always wanted to know but never took the time to look up.

  • Chin

    Reply Reply October 3, 2014

    Useful research based info! Once I was as skeptical as others on this forum, but now it settles most of my worry with scientific and research references, it really changes my view on the uses of microwave.

  • Doug

    Reply Reply October 3, 2014

    I was never too worried about microwaves but I have heard those myths before and defiantly wondered about them. This is great information that you provided and puts the questions about microwaves, their harmful effects, and how they work aside. Thank you!

  • Suzan

    Reply Reply October 5, 2014

    Great article and thanks for sharing. It certainly alleviated the myths and concerns I had about using microwave ovens. As a working mother and wife this also removes the guilt of using my microwave in preparing meals quickly for my family after a hard day at the office.

    Thanks much.

  • Linda

    Reply Reply October 8, 2014

    Very reassuring. Love the simple, easy to understand approach. My husband has always been wary of microwaves and it possibly wasn’t my first choice when cooking but now I feel a bit more confident to do the veg in the microwave rather than a saucepan. I will also review the dishes I use in it. Back to Pyrex and get rid of the plastic. Thanks Linda

  • Gillian Stearn

    Reply Reply October 9, 2014

    Again, another fantastically informative article from The Health Sciences Academy. I have owned and used a microwave since the middle 80’s. On the odd occasion I have felt a bit uncomfortable standing in front of my oven “just in case it emits radiation”. I now completely understand how microwaves work after reading this article. After reading other articles on this brilliant website I now understand much more regarding nutrients, vitamins etc. and have advised my son (who is a qualified chef and father) that there are many more things that are better being cooked in the microwave as this way retains more vitamins and minerals. We both use a hallogen oven because it is economical and also we can steam, grill, roast, poach using around 30+ % less electricity. I have liked this on Facebook and will continue to like because I want my friends to know what a very informative important website The Health Sciences Academy Organisation is.

    I cannot wait for my Monday and Thursday email with great articles and comments/feedback.

  • Kit Berry

    Reply Reply October 13, 2014

    Very helpful article – thanks. I’m very concerned about the use of plastics and how the BPA is affected by heat, creating dioxins that may lead to cancer. I never leave a plastic drinking bottle in the sunlight or a hot car, and always avoid using plastic in the microwave. A blog about this subject would be really useful if you could please do one at some point. Thanks

    • admin

      Reply Reply October 13, 2014

      Hi Kit, thanks for your suggestion for a future topic! In the meantime, have a look at the BPA hyperlink in this article :)

  • Shelly

    Reply Reply October 21, 2014

    I just wanted to share some information about Ionising Radiation from X-rays:

    “But there is no threshold below which this kind of radiation is thought to be totally safe.”

    “When it comes to assumption number one, there are no studies that can prove that small doses of x-rays are risk free. Just a single photon can damage a cell’s DNA, and send it on the path to malignancy.”

    “Gofman, who for decades has warned of the dangers of low-level radiation, concluded that the cause is medical X-rays, including fluoroscopy and computed tomography or CT scans. The analysis and conclusions are published this week in a 700-page monograph by the book division of the Committee for Nuclear Responsibility, Inc., a non-profit, public interest association Gofman founded in 1971.” John W Gofman, professor emeritus of molecular and cell biology at UC Berkeley

    “It has been known for decades that high doses of radiation injure or kill the heart and blood vessels,” Gofman said. “This study is about low and moderate doses accumulated over time. Each dose, no matter how low, produces mutations, so by the time you’re 50, all of these events have added to the mutation load in your cells.” John W Gofman, professor emeritus of molecular and cell biology at UC Berkeley

    I just wanted to share this as there is a misconception that ‘low’ levels of radiation are safe (doctors push this all the time). But I experienced it for myself earlier this year when my dog went in for x-rays because he was limping and 3 weeks later had a lump in his throat. Two months after that he passed away from cancer. After careful research, I’ve learned that x-rays are not safe – on any dosage level.

    • admin

      Reply Reply October 21, 2014

      Thanks, Shelly – this can be an idea for a different article about radiation from X-rays on its own. Regarding cooking, following the manufacturer’s instructions for the safe use of microwaves is very important.

  • Maurice Castelijn

    Reply Reply October 21, 2014

    Shelly, very sorry to hear about your dog… I thought those articles were a worthwhile read and wanted to say thanks for sharing those.

    It also inspired me to revisit the electromagnetic spectrum again – even if just to refresh my own grey cells – and I found this NASA explanation, which I thought was worth linking back here. It explains the differences between x-ray and microwave radiation for example quite nicely:

  • julia woodman

    Reply Reply December 17, 2014

    thanks, i found this reassuring, and have shared widely

  • Rhoda

    Reply Reply January 9, 2015

    Thank you for that information, now I can use my microwave in safety, without worrying that it will harm me.
    A question if I may ask: Why is it that the food or drink, when heated in the microwave goes cold very quickly???

  • Daniel Hynes

    Reply Reply March 6, 2015

    This is what I love about doing my course: concise, clear, superbly written. I was definitely one of those that harboured a hesitancy when it came to microwave usage. Glad that this was addressed as I can imagine many, many clients will harbour these same feelings of unease!

  • Soloni Freitas

    Reply Reply March 21, 2015

    Thanks Alex! As I was learning about free radicals I also started think about microwaving food and I was so glad that you added this article in the chapter. Now I can feel a peace of mind when I go ahead and just to use it. Thank you again.

  • katie

    Reply Reply July 20, 2015

    very interesting article, ive never heard this type of explanation, I just knew I used the microwave and it was supposedly bad for you and to avoid it as much as possible..
    That poses a few questions…

    why are statements said not to microwave baby formula, if it just activates water molecules to heat up why the statement?
    I heard the experiment that someone did on some plant seeds (I don’t remember the precise plant) and they proved that watering the seeds with microwaved water actually never produced a sprout. Why? if the electrons are just shaken to warm up then cooled off why such a result?

    does it change the structure of the water base? im sure there is condensation but why would it not allow a sprout?

    • Hi Katie – Nice to hear you found the article helpful. Regarding baby formula, it’s not microwaves on their own but the BPA in plastic containers, so glass is better. There’s no scientific validity in the plant seeds story, which is anecdotal (made up). You’d need hundreds of thousands of seeds in a lab to do a proper experiment and remove the possibility of faulty seeds and many other variables. Even then, there would be no difference other than bacterial removal from the water, just like when you boil or sterilize it. There’s a lot of pseudoscience out there and you should always be cautious about the source of information. Here’s a good list of red flags to watch out for to distill good science from bad science: Enjoy! Maria (THSA team)

  • Georgina

    Reply Reply September 9, 2015

    Hello, I am reassured that microwaves will not harm us unless used unsafely. I will let those who have concerns know what I have learnt. When defrosting food, how come part of the food can be cooked and part of it still frozen? Is it a microwave technical issue? Or am I doing it wrong? thanks

  • Harvey Caine

    Reply Reply September 18, 2015

    I have heard that microwaves create free radicals, no?
    These could be rumors.
    However, as an energyworker I can feel the choatic energy of food after microwaving. It is distinctly different than food heated naturally. Standing near microwaves feels physically unpleasant.generating a subtle headache. As a result I’m not inclined to eat microwaved food often.

    • Above all, you do need to follow the manufacturer’s instructions for safe use of the microwave ovens, and ideally change yours if it’s older than 10 years. Microwaves are contained so that the non-ionising radiation needed to heat the food stays inside the microwave. This means that when used properly, microwaves should pose no concern. The only time that our cells would get exposed to the radiation, is if the microwave is really old or damaged and some of the radiation could leak out.

      Regarding your question about free radicals:

      ​​​In comparison with radiation burns caused by ionising radiation (where the dominant mechanism of tissue damage is internal cell damage caused by free radicals), the primary damage mechanism of microwave radiation is thermal, by dielectric heating.

      Research shows that steaming and microwave cooking are the lowest-producing of food mutagens and genotoxins in cooked foods. Both cooking methods have been shown to retain the integrity (free-radical scavenging capacity) of plant antioxidants to a greater extent than other high-heat cooking methods, such as deep-frying, which produces the largest amount of free radicals from the damages to the oils used. See here:

      ​​We teach the ins and outs of cooking and food mutagens in our Detox Specialist course (, based on the scientific evidence – as opposed to hear-say and fear-mongering. There’s a lot of “bad science” on the internet, here’s four red flags to pay attention to when you read information online:

      Also have a look at this useful article about oils for cooking: ​​

      I hope this helps :-)

  • Mary

    Reply Reply March 20, 2016

    You can read so much on the internet about the latest scandals in health to do with microwaves and plastic containers. I am a firm believer that there are more harmful ways to pollute your body then reheating your food in the microwave. This article has reassured me that you cannot trust everything you read and I will be sharing this with others to show that when it comes to nutrition – trust the experts not wannabe food bloggers!

  • Wasili

    Reply Reply July 10, 2016

    The world around us is filled all sorts of myths about the use of items such as cellphones, microwaves, autoteller machines, etc.
    The ionising radiations such as alpha, beta and gamma are not used in microwaves. Instead, it is the non-ionising radiation that is harnessed. Since this radiation does not knock off electrons from atoms so that cancer-causing ions and radicals are created, we can rest assured that there is no risk associated with the use of microwaves.
    As science-loving individuals, we should shun away from drawing inappropriate conclusions from myths.
    Let’s teach the humankind only that which is right!

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