Are Microwave Ovens Safe? What Science Really Says About Microwaves, Your Food And Your Health

Are Microwave Ovens Safe?: A Burn the Fat Blog Archives Classic. Originally published July 12th, 2011.

“Microwave ovens will kill you!” Or so they say… If you’ve ever surfed the internet for information on health and nutrition, there’s little doubt you’ve come across scare stories about microwave ovens. Online natural health “experts” claim that microwaves will “zap” your food, deplete it of important nutrients and alter its molecular structure in dangerous ways. They also warn that microwave exposure and eating food cooked in microwave ovens will cause harm to your body and even cause cancer!

Is there any truth to any of these reports? Why are some people so paranoid about an appliance that has been used safely by millions of people for decades? Should you stop using a microwave oven for reheating leftovers, making frozen dinners or cooking your vegetables, potatoes, meat, oatmeal or other foods?

These are important questions because: A) your health is your number one priority and B) the microwave oven, while it may not replace a conventional oven and certainly doesn’t produce better tasting food, is unquestionably one of the greatest time savers and conveniences you can have in your kitchen.

You’re not only about to get the answers, this also will be the last article about the microwave controversy you’ll ever have to read because it demolishes the microwave myths with undeniable proof: facts, science and evidence… not urban legends and fear mongering.

What started all the internet scare stories?

Rumors are often started and circulated on the internet without anyone ever confirming the source. Did you ever get one of those random emails that said something like, “10 reasons to throw out your microwave” and then forward it right on to a friend, just assuming it was true? (go ahead, fess up).

A large part of all the microwave alarmism today can be traced back to a single story that was spread on the internet until it went viral and was eventually accepted as factual.  It’s the story of the infamous “Swiss research” done by “food researcher” Hans Hertel, who allegedly performed his own private study to see how microwaved foods affected the results of blood tests. A typical iteration of the story goes like this:

“The use of microwave ovens in cooking can alter the structure of nutriments in foods, making it difficult for the organism to make use of them. Hertel discovered that food cooked or thawed in a microwave oven could cause changes in the blood, indicating that a process of illness is developing. SIMILAR CHANGES ARE ALSO FOUND IN THE CASE OF CANCER.”

As with most alarmist nutrition nonsense on the net, this one also involves the ubiquitous conspiracy theory. The story continues:

“The best studies about the use of microwaves to heat food were purposely kept from consumers. Hertel was efficiently “gagged” by Swiss microwave oven producers. For over 10 years, Hertel has fought for the right to tell the world what he’d discovered.”

Debunking an Internet hoax

Actually the best studies are NOT kept from consumers, they are peer reviewed, replicated and published in scientific journals where we can actually look them up. Alas, we cannot access Hertel’s “research” to judge its validity because it was never published.

In fact, by Hertel and his follower’s own accounts, this “study” was just himself, Bernard Blanc (who later recanted) and six of their buddies who locked themselves in a hotel room and conducted a personal and arguably non-scientific and non-controlled experiment.

This is not real research; it was never verified or replicated by other researchers. Yet you see Hertel quoted in almost every “microwaves equal death” article on the Internet, a good tipoff that everything else in the article is B.S. as well.

Microwave ovens, radiation and the cancer scare

One tactic used by microwave scaremongers is to instill fears about radiation and cancer.  When people hear the word radiation, they tend to freak out.  I suspect that even people who understand that we’re not talking about a nuclear accident, gamma rays or x rays still have an uncomfortable feeling about “radiation” cooking their food (after all, we call it “nuking” right?)

But when we talk about microwave “radiation” we are simply talking about production of thermal energy, aka, heat. Radiation and radioactive are NOT the same thing. Celeste Robb-Nicholson, M.D. from the Harvard Health Review explains:

“Microwaves do not cause cancer. They’re a form of non-ionizing radiation and thus cannot ionize tissue. Microwave ovens use low-frequency waves of electrical and magnetic energy to produce heat to cook food. They don’t make food radioactive, nor do they trigger cancer-causing genetic mutations.”

A search of the medical literature brings up absolutely nothing linking microwave cooking to cancer.

The research says that concern over cancer causing compounds such as heterocyclic amines (HCAs), and polycyclic aromatic hydrocarbons), would be better directed toward educating consumers on the charring and blackening that occurs when grilling or barbecuing muscle meats, rather than cooking the meat in microwave ovens.

In fact, cooking in a microwave can actually REDUCE the formation of HCAs. This quote comes from the National Cancer Institute (www.cancer.gov):

“Studies have shown that microwaving meat prior to cooking helps to decrease mutagens by removing the precursors. Meats that were microwaved for 2 minutes prior to cooking had a 90-percent decrease in HCA content.”

Microwave radiation leaks

Although microwaves are a form of non-ionizing radiation, you wouldn’t want prolonged exposure to them at high power any more than you’d want to stick your head in the conventional oven on high and leave it there.  You also wouldn’t turn the temperature up in your house to 325 degrees to roast a turkey – the idea is to cook the bird, not you.  So what if the microwaves get OUT of the oven? Could they hurt you then?

In the early days of the microwave oven, leaks were more of a concern due to imperfect oven designs. Due to federal standards and improved engineering today, experts agree that this is now a non-issue. According to the FDA, there is little cause for concern about microwaves leaking from the oven unless the door hinges, latch or seals are damaged. (you can always buy a leak detector if you’re paranoid).

If you’re still worried, simply back away from the microwave while it’s running. Microwave energy rapidly dissipates as you move away from the source. Also, the way microwaves are manufactured, the second the door is open the device shuts down and no radiation leaks out after you’ve opened the door.

Do microwave ovens alter the molecular structure of food in unhealthy ways?

NO! There’s no evidence that microwave cooking alters the molecular structure of the food in a damaging and unhealthy way.

At Mercola dot com, which claims to the #1 natural health website online, the controversial alternative-natural health doctor Joseph Mercola has published alarmist articles that have spread microwave worries all across the internet like wildfire.

Mercola claims that microwave ovens are a toxic threat to you and your family. He says that “microwaving distorts and deforms the molecules of whatever food or other substance you subject it to.”

Well, no kidding the molecules change; that’s called cooking and the molecular changes caused by cooking a food in a microwave are no different and no more harmful than the heating of a food any other way.

Conveniently, Dr. Mercola, who has received numerous warning letters from the FDA for making unsubstantiated claims in marketing, will be glad to sell you his convection oven after you read his article that scares you into throwing out your microwave.

Mercola also claims that “your microwave turns your beautiful, organic veggies, for which you’ve paid such a premium in money or labor, into “dead” food that can cause disease.”

Wrong again. There’s been no human research ever published to prove that microwaved foods cause disease, just a bunch of conspiracy theories and alarmist rantings.

However, a Dutch study in 1995 that was published in the journal Food Chemistry did conduct a toxicity experiment on rats using human food that found the opposite. The researchers intentionally subjected the food to misuse treatment by reheating in a microwave repeatedly to make sure to concentrate any potentially harmful substances. The tests were exhaustive and no harmful effects were found:

“Criteria to assess toxicity included clinical observations, ophthalmoscopy, growth, food and water intake, haematology, clinical chemistry, urinalysis, organ weights, micronucleated erythrocytes in bone marrow, gross examination at autopsy and microscopic examination of a wide range of organs. The results indicate no adverse effects of the diets cooked by microwave compared with those cooked conventionally.”

Do microwave ovens zap the nutrition right out of your food?

What about the criticisms that nutrients get “zapped” right out of the food when you “nuke” them? They’re factual aren’t they?

There’s a sliver of truth to this, but all cooking can destroy nutrients. What the microwave critics don’t tell you is that microwave cooking can actually preserve nutrients better than some other cooking methods like boiling. Minerals hold up particularly very well.

At least two studies did raise concern over major flavonoid losses in broccoli and one over vitamin C. One of the studies showed a 97% loss of flavonoids in the broccoli, which has been the basis of the “microwaves zap nutrients” myth ever since.  If microwave fear-mongers actually read the studies however (imagine that), they would see that the major nutrient losses were created by cooking the veggies in a lot of water.

Nutrient losses while microwaving depend mostly on cooking power, cooking duration and volume of cooking water.

The studies did not conclude that you shouldn’t cook in a microwave oven, they concluded that steaming is the preferred method for retaining the most nutrients in vegetables and that if you cook broccoli or other veggies in a microwave, don’t overcook them and don’t cook them in water.

Vitamin losses from cooking meat in the microwave have also been studied. A 1998 study from Japan showed a 30% loss of vitamin B-12 from cooking meats in a microwave. However, it’s not a massive nutrient loss compared to boiled vegetables and since B-12 is heat sensitive, similar losses occur from conventional cooking as well, so once again it’s not a microwave-exclusive problem.

Many people don’t care for microwaved meat anyway (the common joke is “tastes like rubber”), but all things considered, studies say that microwaving your veggies is not a bad way to cook them. In fact, some research says microwaving retains more nutrients due to the fast cooking times. A 1982 study by Cross and Fung published in Critical Reviews in Food Science and Nutrition concluded:

“Overall, the nutritional effects of microwaves on protein, lipid, and minerals appear minimal. A large amount of data is available on the effects of microwaves on vitamins. It is concluded that there are only slight differences between microwave and conventional cooking on vitamin retention in foods. In conclusion, no significant nutritional differences exist between foods prepared by conventional and microwave methods. Any differences reported in the literature are minimal.”

Will microwaves destroy your precious protein?

Here’s an issue that concerns some of us bodybuilders and fitness minded folks:  Does microwave cooking damage or denature protein?  This too has been researched and once again the microwave fear-mongers are wrong when they claim that microwaving ruins the protein.

In the Journal of Scientific Food Agriculture, Jonker and colleagues wrote:

“In general, the nutritive value of proteins in foods is comparable, whether cooking is done by microwaves or conventional means…”

Cooking at high temperatures has potential to denature protein, but that’s an excess  heat issue, not a microwave oven issue.  The amount of denaturation depends on how long and at what temperature the food is cooked.  Some of the more delicate biological subfractions could be damaged or destroyed in proteins like whey, but that doesn’t mean the protein quality or amino acids themselves are destroyed.

On a related macronutrient note, research from Poland studied the effect of conventional cooking versus microwaving on essential fatty acids in herring. There was no damage to the omega-3 fatty acids.

Non uniform heating of food: Caution! Watch out for hot spots!

Have you ever noticed how some parts of your microwaved food are cooked thoroughly and others are still luke warm or even cold? It can definitely be annoying, but experts have expressed a serious concern over the potential for burns in adults, children and infants because one portion of the food can be cool or warm and another scalding hot.

Microwave technology has improved over the years to help mitigate this “hot spot” problem (including rotating carousels), but non-uniform heating is always somewhat of an issue to be aware of when consuming food cooked with microwave ovens.

This problem is easily solved with a little common sense and caution. Just mix or stir your food, and let it stand briefly before eating it. Eat hot food with caution.

Bacteria worries

Health alarmists often publish claims that deadly and dangerous bacteria can survive in foods cooked in a microwave oven. There have indeed been case studies published in medical journals about listeria, ecoli and salmonella. But guess what – it can happen with any cooking method if the meat isn’t cooked completely.

Microwave ovens are used most often for reheating food, but some people use microwaves to cook raw meats. Because microwave ovens may heat food non-uniformly, if you try to you cook a whole, stuffed chicken in the microwave, some areas may not get cooked completely, so ecoli or listeria, if present, may not be destroyed.

If you don’t want to take any chances, don’t cook whole raw chickens in the microwave!

Same thing with eggs. Lightly cooked eggs could harbor salmonella. Whether you’re using a microwave or a conventional stovetop to cook eggs, make sure they’re fully cooked. Salmonella risk from eating raw eggs is very low, but eat them raw at your own risk (you only need ONE good case of food poisoning in your lifetime to never ever want to experience it again).

By the way Rocky Balboa wannabes, a study from the Journal of Nutrition showed that eggs are more digestible when they’re cooked, not raw.

Exploding eggs?

Speaking of eggs, this may sound strange, but there have been at least four papers published in medical journals which reported cases of eye injuries from the explosion of microwaved eggs.

One published in the journal of ophthalmology in 1998 wrote up two case studies and said that the flying hot eggs caused serious injuries:

“The first patient required limbal conjunctival transplantation and a subsequent penetrating keratoplasty in the right eye and prolonged treatment of superficial keratitis in the left eye. The second patient sustained bilateral corneal epithelial defects and unilateral intrastromal hemorrhage.”

I don’t cook my eggs in the microwave, I think they have the texture of rubber.  But if you nuke yours, ironically, there’s more legitimacy to a rare freak exploding hot egg accident than the ridiculous claims of cancer.

Also, on a slightly tangential, but related note, the eye is a vulnerable organ due to the anatomy and physiology of the lens, so it’s prone to overheating with overexposure to microwaves. Does this mean microwave ovens are unsafe? No. It would only be a danger in the kitchen if your microwave oven screen or door mechanism were faulty and you sat there with your nose pressed up against the glass (see section on radiation leaks above).

Microwaved milk and infant formula dangers?

Anti microwave websites often mention that microwave-heated baby formulas and breast milk should not be fed to infants, based on potential damage to the milk itself or potential burn injuries.

One study from the Stanford University School of Medicine was published in the journal Pediatrics. They tested 22 human milk samples for lysozyme activity, total IgA, and specific secretory IgA to E coli by heating them by microwave at various low and high power settings. They concluded that microwaving appears to be contraindicated at high temperatures due to nutrient damage, and questioned microwave use even at lower temperatures.

The Stanford study is selectively quoted all the time by anti-microwave groups. What about the rest of the research? A study published in the International Journal of Food Science and Nutrition said, “microwave heating of human milk can be performed without significant losses of examined immunoglobulins and nutrients, provided the final temperatures are below 60 degrees C.”

Also, let me quote Jonker again from The Journal of Scientific  Food Agrigulture:

“When the microwave treatment is well controlled to avoid overheating, such biological properties as the clotting activity of plasma and antibacterial activities are reasonably maintained.”

As I mentioned earlier, it appears that overheating any food with any cooking method could destroy a small portion of the nutrients, but it doesn’t make the food harmful to eat. As noted above, heating in a microwave does not create or add any toxic compounds to foods or drinks.

Superheated liquids? (It made “MYTHBUSTERS”)

Burns are a possible safety concern due to the uneven heating of food. There’s also a potential danger for anyone to get scalded due to overheated liquids (or steam).

In microwave ovens, the water can become superheated past its boiling point and yet bubbles don’t form. When the liquid is disturbed or something is dropped in it, like sugar, the heat is released, and it’s possible for boiling water to bubble over and out of the container.

There’s an urban legend that that microwaved water can explode in your face. While it may not explode literally, this is not a complete myth – microwave water or hot beverages can bubble over aka “erupt” due to the superheating phenomenon (water in a liquid state that is over 100 degrees celsius). This was actually tested on an episode of MythBusters (video below).

Burns from liquids could happen to adults, children or infants from overheating or spills. In one unfortunate case study from a hospital, the teat from an infant’s bottle that had been heated in the microwave exploded scalding hot milk on the child resulting in extremely serious burn injuries to the face, mouth, trachea, palate, pharynx and esophagus.

Of course, grown adults have been known to burn themselves in kitchen mishaps or even on McDonalds coffee (and then sue). But don’t blame the microwave (or Mcdonalds), just be careful of hot stuff, folks. Hot stuff burns, you know.

What about about plastics releasing toxins into the food?

Lots of people are worried about cooking in plastic containers these days. Can’t chemicals leach out of the plastic and into your food? Sometimes they can. But that’s what microwave safe containers are for.

A Greek study found that dioctyladipate (DOA) and acetyltributylcitrate (ATBC) plasticizers from food-grade PVC and PVDC/PVC leak into olive oil and water when cooked in the microwave.

A study from the European food research and technology journal found that DOA and ATBC plasticizers from plasticized poly(vinyl chloride) and poly(vinylidene chloride/vinyl chloride) films migrated into ground meat of varying fat content during microwave heating.

The most recent concerns have been over Bisphenol A (BPA), a plasticizer used in polycarbonate plastics such as storage containers, bottles and even can liners. How much can leach into food, under what circumstances and what are the health consequences are hotly debated and this subject goes far beyond the scope of this article.

Even though there’s some truth to the concerns about plastics, they’re often overblown and mixed in with myths (the dioxin chain email hoax comes to mind). And of relevance to our discussion, this is not a microwave problem, it’s a heating of certain plastics problem.

The simple solution: use only plastic containers that are microwave-safe or to be absolutely sure, stick with corning ware, ceramics or microwave safe glass. If you cook with saran wrap in the microwave, avoid direct contact of the wrap with the food. Do not use cold storage containers or foam insulated containers in the microwave either.

Are microwave ovens Safe? Yes. The real danger is getting second hand natural health information off the internet

As you can see, there are some legitimate microwave oven safety issues to be aware of, but they’re no different than basic cooking safety with any kind of conventional oven, stovetop, grill or fire.

If you pay attention, you’ll notice that nearly all of the “gloom and doom” stuff is uncritical, propagandist pseudoscience coming from the “alternative health,” “natural health” or “raw foods” movements (by the way, some nutrients become more bio-available when cooked).

Some of the people and organizations who spread this misinformation are honest and sincerely believe in what they’re saying. But as physicist Robert Park wrote in Voodoo Science, “what may begin as honest error has a way of evolving through almost imperceptible steps from self-delusion to fraud.” True to that point, some are using scare tactics as tools for marketing or furthering their agendas.

Other people are just “out there.” I swear some of them are conspiracy theory, tin foil hat and little green men types.

And this months Tin foil hat award goes to…

I’ve had some of these natural health alarmists tell me that there’s no research proving microwaves are safe and we have no way of knowing they won’t cause cancer in the long term.  Well no kidding you can’t prove a negative, but that line of argument alone shows the fallacy in their way of thinking.

Enormous amounts of research have been done for decades on the question, are microwave ovens safe, and any physicist or food scientist can explain to you how they work to safely cook your food (a couple of them do just that, below).

To many of these internet kooks, “research” means quoting other natural health websites, which in turn, quote other natural health sites and regurgitate urban legends. Even authorities with real credentials like M.D. are fallible and not above reproach.

What about me? Why did I write this long article on microwaves? Do I have some kind of agenda of my own?

I’m a bodybuilder, but I’m not just interested in muscle mass and ripped abs. Health is my top priority.  If microwave ovens caused health problems, I’m the first person to want to know about it because I use the microwave a lot.  I use it to heat coffee or tea, to thaw meats, to cook my oatmeal every morning and for cooking potatoes and yams (I do prefer those baked, but the microwave is faster).  I also cook my veggies in the microwave and reheat pre-cooked meals.

I estimate that I use a microwave at least three to five times a day and I’ve done that almost every day for the last 25 years. I asked myself the question, ‘are microwave ovens safe’ many times. Based on my use, if microwaves were harmful, I figure I’d be a prime example of someone who should have health problems. I don’t. My health is perfect. I have not been to a doctor for illness or injury in nearly 30 years and I continue to set personal records in the gym today in my late 40s.

I have no pro-microwave agenda and in fact, I’m interested in a natural approach to health and bodybuilding – it’s real food and drug-free for me – natural for life and not a prescription to be found in my medicine cabinet. ..
I’m simply sick of poorly-researched, non-vetted misinformation about health and fitness, and a few myths promoted by alternative natural health publishers have always pushed my buttons and irritated me to the brink of insanity. The microwave myth is one of them.

Just to be fair, let me say that I agree it’s intelligent and prudent to question what we eat, how what we eat is processed and even how what we eat is cooked. However, we must question critically and look at real evidence before jumping to conclusions and spreading panic around the net. Stop and think first, before you click the “forward” or “share” buttons.

But hey, I’m a “muscle-head,” not a biochemist, a physicist or a food scientist, so don’t listen to me if you don’t want to. Fact check my article and look up all the references for yourself… AND let me close with some feedback from a couple of people who ARE food scientists.

Conclusions from food scientists

Elissa Lowe is a blogger for ultimate fat burner dot com and shes a senior moderator at Will Brink’s bodybuilding and fat loss forums. She also has a science background with degrees in food technology and she’s one of the sharpest ladies in this field, not to mention one of the fittest (she can kick ass in a gym OR in a debate). I asked her if microwaved foods were safe and here’s what she told me:

“Are microwaved foods safe? If your only source of information is the internet, I wouldn’t blame you for having some doubts! There are a lot of scary stories floating around in cyberspace. For example, on one popular web site, I learned that microwave ovens “…threaten your health by violently ripping the molecules in your food apart.”
Say, what?! As someone who’s studied a LOT of chemistry and biochemistry, I have NO idea what that even means. Scientifically, it’s nonsense.

But that’s the point: statements like this are designed to frighten… not enlighten. I’ve looked into several references cited as “proof” of the “dangers” of microwave ovens (such as the alleged “toxicity” of microwaved blood; the destruction of bioactive compounds in breast milk, the Swiss “clinical study,” etc.), and, in each case, I’ve discovered that reality has seriously been distorted to support a preconceived, “denialist” position.

What can I say? There are a lot of paranoid people out there… not to mention those who are all-too-willing to stoke paranoia for profit. As this well-known parody on the dangers of “dihydrogen monoxide” demonstrates, anything can be made to sound sinister: www.dhmo.org/

So what’s the truth? Food scientists have researched the effects of microwave cooking to the nth degree. “Big Food” isn’t overly concerned about your health, but it is concerned (obsessed, really) with creating completely uniform consumer products. Thus, every aspect of production and routine consumer handling is understood… in mind-numbing detail. Sure, papers like “Physicochemical Changes in Dietary Fiber of Green Beans after Repeated Microwave Treatments,” or “Mutagen Formation in Beefburgers Processed by Frying or Microwave with use of Flavoring and Browning Agents” are duller than dirt. Nonetheless, they’re part of a looooong, detailed and – most importantly – scientifically legitimate “paper trail” on the effects of microwave cooking.

Reading these unexciting papers leads to an equally unexciting conclusion: there’s nada that happens to food cooked in a microwave that doesn’t also happen with other forms of cooking. Where differences (positive or negative) exist, they’re in the degree; not the type. Scientists have searched for “athermal” or “non-thermal” reaction products that might be harmful to human health, but nothing unusual has been found. Research in model, non-food systems suggests there may be alterations in the rates of certain reactions (such as protein unfolding) which can’t be explained solely in terms of thermal effects, but that’s about it. No “unique radiolytic compounds” – let alone toxic ones – have been discovered.”

I also contacted Ashim Datta, a professor of biological and environmental engineering at Cornell University. He’s the author of numerous research papers, book chapters and books, including the Handbook of Microwave Technology for Food Applications. I asked Dr. Datta the same question and here was his reply:

“Based on my knowledge of the last 30-35 years of research literature on microwave heating, microwaves have only thermal effect, i.e., increase in temperature. There is no other “microwave” effect. Because microwaves heat non-uniformly, some places can heat a lot more and get charred and produce undesirable compounds. This, however, is just as true with any heating process, including hot air or grill. For the same reason of non-uniform heating, some locations in the food can heat a lot less and thus not destroy enough of pathogenic microorganisms (when this is an issue), causing a food safety problem, in much the same way as in conventional heating. Absolutely no negative health effects of microwave heating have been shown conclusively in all these years since microwave heating was started in the 50s.”

Can we finally close the case now on all the microwave oven alarmism and move on, or do we have to give away even more tin foil hat awards and start dispensing baloney detection kits?

Scientific References:

Phenolic compound contents in edible parts of broccoli inflorescences after domestic cooking Journal of The Science Of Food And Agriculture, F Vallejo, at al, Laboratorio de Fitoquimica, Departamento de Ciencia y Tecnología de los Alimentos, Murcia, Spain

The effects of microwaves on the nutrient value of foods, Cross, GA and Fung, D., Critical Reviews in Food Science And Nutrition, Vol 16, No 4, pp 355-419, 1982, Department of Animal Sciences and Industry, Kansas State University

The effect of cooking methods on total phenolics and antioxidant activity of selected green vegetables, Turkman N et al, Food Chemistry 93(4), pp 713-718, 2005, Department of Food Engineering, Ankara University, Turkey.

Retention of nutrients in microwave-cooked foods, Klein BP. Bol Asoc Med P R., 1989 Jul;81(7):277-9.

Effects of Microwave Heating on the Loss of Vitamin B(12) in Foods, Wtanabe, F, et al, J Agric Food Chem. 1998 Jan 19;46(1):206-210, 1998, Department of Applied Biological Chemistry, Osaka Prefecture University, Japan.

Effects of microwave cooking conditions on bioactive compounds present in broccoli inflorescences, Lopez-berenguer C et al, J Agric food Chem, 55(24) pp 10001- 10007, 2007.

Comparative sub-chronic (13-wk) toxicity study in rats, Jonker, D., Food Chem Toxicol, 1995 Apr;33(4):245-56, TNO Nutrition and Food Research Institute, Zeist, The Netherlands.

Comparative study of the nutritive value of casein heated by microwave and conventionally, Jonker D, Jour Sci Food Agric, vol 59, pp 123-126, 1992.

Chronic, low-level (1.0 W/kg) exposure of mice prone to mammary cancer to 2450 MHz microwaves. Frei MR et al. Radiation research 150 (5): 568-76. doi:10.2307/3579874. 1998

Chronic exposure of cancer-prone mice to low-level 2450 MHz radiofrequency radiation. Frei, MR; et al.Bioelectromagnetics 19 (1): 20- 31. 1998

Survival of Listeria on raw whole chickens cooked in microwave ovens., Farber JM, D’Aoust JY, Diotte M, Sewell A, Daley E. J Food Prot. 1998 Nov;61(11):1465-9. Microbiology Research Division,  Health Canada, Ottawa, Ontario, Canada.

Survival of Salmonella species in eggs poached using a microwave oven, Bates CJ, Spencer RC. J Hosp Infect. 1995 Feb;29(2):121-7.Department of Bacteriology, Floor F, Royal Hallamshire Hospital, Sheffield, UK.

The effect of short-time microwave exposures on Escherichia coli O157:H7 inoculated onto chicken meat portions and whole chickens. Int J Food Microbiol. 2005 May 1;101(1):105-10. Epub 2004 Dec 25.Apostolou I, et al. Food Microbiology Unit, Medical School, University of Ioannina, Greece.

Effect of microwave heating on the migration of dioctyladipate and acetyltributylcitrate plasticizers from food-grade PVC and PVDC/PVC films into olive oil and water , Z Lebensm Unters Forsch. 1996 Apr;202(4):313-7. Dept of Chemistry, University of Ioannina, Greece.

Effect of microwave heating on the migration of dioctyl adipate and acetyltributyl citrate plasticizers from food grade PVC and PVDC/PVC films into ground meat, Badeka, European food research and technology, vol 208, no. 1, pp 69-73

Potential migration release of volatile compounds from plastic containers destined for food use in microwave ovens, Nerin, C., et al, Food Addit Contam, bol 19, no. 6, pp 594-601, 2002. Universidad de Zarogazo, Madrid, Spain.

Burns associated with the use of microwave ovens, Budd R., J Microw Power Electromagn Energy. 1992;27(3):160-3, Radiation Biology Branch, Center for Devices and Radiological Health, Food and Drug Administration, Rockville, MD.

Corneal injury from explosion of microwaved eggs. Yoo RT, Rivera PM, Campbell JP, Butrus SI.Am J Ophthalmol. 1998 Mar;125(3):390-2. Washington National Eye Center, Washington Hospital Center, DC, USA

Severe burns resulting from an exploding teat on a bottle of infant formula milk heated in a microwave oven. Dixon JJ, et al, Burns. 1997 May;23(3):268-9. Frenchay Hospital, Bristol, UK.

Effects of microwave radiation on anti-infective factors in human milk, Quan R, et al, Pediatrics. 1992 Apr;89(4 Pt 1):667-9.Department of Pediatrics, Stanford University School of Medicine, CA.

Electromagnetic radiation from microwave ovens. Alhekail ZO. EE Dept., J Radiol Prot. 2001 Sep;21(3):251-8. King Suad University, Riyadh, Saudi Arabia.

Comparison of the effects of microwave cooking and conventional cooking methods on the composition of fatty acids and fat quality indicators in herring. Regulska-llow B, Ilow R.1: Nahrung. 2002 Dec;46(6):383-8. Wroclaw Medical University, Department of Food Science and Nutrition, Wroclaw, Poland.

Heterocyclic amines: Mutagens/carcinogens produced during cooking of meat and fish. Sugimura T, et al, Cancer Sci. 2004 Apr;95(4):290-9. National Cancer Center, Chuo-ku, Tokyo 104-0045, Japan.

Physiochemical changes in dietary fiber of green beans after repeated microwave treatments, Svanberg M et al, Food Science, 62:5, pp 1006-1010, 1997.

The effect of microwave heating on vitamins B1 and E, and linoleic and linolenic acids, and immunoglobulins in human milk., Ovesen, Int J Food Sci Nutr, Vol 47, No. 5, pp 427-436, 1996

Dissecting an Internet hoax: water, food, plastics, and microwaves, Pike-Paris Ann, Pediatric Nursing, 31(6):503-7, 2005.

Recommended reads:

Superheating and microwave ovens: University of Sydney, School of Physics
USDA report on Microwave ovens and food safety
FDA’s microwave oven radiation page
Microwave Myths by the Center For Science In The Public Interest (CSPI)
Skeptoid picks apart the “10 reasons to throw out your microwave” chain e-mail
Heterocylic Amines in Cooked Meats – National Cancer Institute

Video:

History of the microwave (Raytheon, Percy Spencer, the melted chocolate bar and the radar range)

MYTHBUSTERS: superheated exploding water