More on Microwave Ovens than You (Might) Want to Know

RE: This Blog

I responded to an earlier Facebook post with a previous blog on microwaves.

My friend read it, then sincerely requested that I address my specific claim that “microwaves distort the molecular structure” of the food itself.  Here is the conversation and my response, which is to copy excerpts from various sources.  This is not interesting reading unless you particularly enjoy the topic, which I myself do not.  I included various footnotes which include a variety of respected journals, like The Lancet, Pediatrics, Nature, and Acres USA.  I generally avoided the Russian studies, but there have been studies conducted across Europe, the U.S., in Japan, and China.

FB FRIEND: We’re so far apart on this one that I’m not sure how to respond. You started with a very specific claim: that “the microwave process distorts the molecular structure of the food itself. Fresh vegetables become altered in a microwave into compounds not recognized by the human body.” That’s a claim which, I think, requires good supporting evidence. If I were to make the same claim about, say, food dehydrators, you’d expect me to provide strong evidence for that. In fact, you’d probably expect me to support it by showing you actual scientific research — controlled studies that have been through the process of anonymized peer review. But you’re not holding yourself to that same standard when it comes to microwaves. Initially you pointed to two pieces of unpublished research with questionable methodology. You’ve responded at more length in this blog entry, but it never really addresses the original question, which is: where’s the evidence for the claim you made?

SCOTT: Ok, I’ll dig onward and provide footnotes. I’m busy today, but go to Atlantis Raising Center (Google). D-nitrosodienthanolamines (microwaved meat) and “reverse polarity.” Radiolytic compounds, Google. S.

FB FRIEND: You’re really directing me to the Atlantis Raising Center in order to find compelling peer-reviewed research? They don’t even appear to have a website, although they’re often cited as being the organization that summarized the Russian research on the subject.
Searching Google Scholar for D-nitrosodienthanolamines turns up nothing relevant. Searching the web turns up loads of copy-pasted references to the same anonymous Russian researchers, without ever giving links to the primary research. Some of the folks on Physics Forum ( tried to track this stuff down and found that a lot of the references were fabricated (eg an often-cited study by Lita Lee in the Lancet).
Searching PubMed for research on microwaves and D-nitrosodienthanolamines turns up exactly nothing (
I repeat: where’s the peer-reviewed research showing any of this stuff?

SCOTT: I appreciate all your efforts and believe you want to know more. I have not responded yet, just making suggestions with limited time today. I’ll get back, tonight maybe, and we’ll see how it goes.

NOW, the following is taken from (Plus more after that!)

Some Russian researchers, in their studies of the changes in food quality when it is cooked in a microwave oven, have reported a marked acceleration of structural degradation leading to a decreased food value of 60 to 90% in all foods tested. They found significant decreases in the bio-availability of B complex vitamins, vitamin C, vitamin E, essential minerals and lipotropics (substances that prevent abnormal accumulation of fat). This was confirmed in a Japanese study when they found that approximately 30-40% of vitamin B12 was lost in foods cooked by microwaves (Watanabe 1998). B12 deficiency is one of several factors that can cause dementia.

Dr C Garcia-Viguera (2003, 2007 (lead author Lopez-Berenguer) found that broccoli lost 97% of its antioxidants (vitamin C) when microwaved. There were also reductions in phenolic compounds and glucosinolates. Mineral levels remained stable. In general, the authors concluded, “the longest microwave cooking time and the higher volume of cooking water should be avoided to minimise losses of nutrients.” She suggested that this may apply to other vegetables, but they were not tested. It was felt that the results could show broad implications for public health.

Scientists at China Agricultural University’s College of Food Science & Nutritional Engineering in Beijing looked at different forms of cooking and their production of acrylamide, a cancer-causing chemical. They found that microwaving produced more acrylamide than boiling or frying (at 180°C), and that 750 Watt ovens produced more acrylamide than 500 Watt ovens (Yuan 2007).

There seems to be a growing body of evidence that suggests that human breastmilk or baby formula is changed if heated in a microwave. The vitamin content is depleted and certain amino acids are converted into related substances that are biologically inactive. Some of the altered amino acids are poisons to both the nervous system and the kidneys (Lee 1989). Paediatrician John Kerner and colleagues at Stanford University found that milk lost lysozome activity, antibodies, and fostered the growth of more potentially pathogenic bacteria (Quan 1992).

The grease-repelling papers used for some microwavable packaged foods, in particular microwavable popcorn, may be responsible for the levels of PFOA, a suspected carcinogen, in the blood of most Americans.

The January/February, 1990, Nutrition Action Newsletter reported on the leakage of numerous toxic chemicals from the “heat-susceptor” packaging of common microwavable foods, including pizzas, chips and popcorn. At the high temperatures achieved in this process, the chemicals in the plastic migrate from the susceptors into your food. The chemicals include polyethylene terpthalate (PET), a petroleum derived product), and other known or suspected carcinogens, such as benzene, toluene and xylene. Haldimann (2007) also found increased concentration of antimony (which in small doses can cause headaches, dizziness and depression), as a result of cooking with polyethylene terephthalate (PET) oven-proof trays (used to package ready-to-eat meals).

It is not recommended that food containing fat in a plastic container should be heated in a microwave oven. The combination of fat, high heat and plastics releases dioxins (a known carcinogen) and other toxins into the food.

Susan Brewster, Associate Professor of Food Chemistry at the University of Illinois, worries about the possibility that certain plasticizers could act as endocrine disruptors, which means they can potentially mimic or compete with human hormones. If they do, then that could affect such things as fertility or someone’s risk of getting cancer.

There has been little research on changes in the consumers of food cooked using microwaves. A piece of work carried out by Hertel and Blanc has been quoted extensively and needs following up. Although they found many and serious changes, including decreased haemoglobin levels and increased cholesterol and leukocyte levels, their research was based on just 18 people, all who ate a macrobiotic diet only, including Hertel himself. It may be that their findings are equally valid for the general public, but without further evidence, we cannot make that assumption. Tom Valentine, an independent US journalist, published the results of this study in Search for Health in the Spring of 1992.

FOOTNOTES (More article to follow):

Garcia-Viguera, C – 2003, Journal of the Science of Food and Agriculture 93; 14

Gittleman, A L – Health Scientist Institute

George DF – 2008, Non-thermal effects in the microwave induced unfolding of proteins observed by chaperone binding Bioelectromagnetics 29(4):324-30

Haldimann M et al – 2007, Exposure to antimony from polyethylene terephthalate (PET) trays used in ready-to-eat meals Food Addit Contam 24(8):860-8

Lee, L – 1989, Lancet, December, and Health Effects of Microwave Radiation – Microwave ovens.

Lopez-Berenguer et al – 2007, Effects of microwave cooking conditions on bioactive compounds present in broccoli inflorescences J Agric Food Chem 55(24):10001-7

Palazoglu TK & V GÖkmen – 2008, Reduction of acrylamide level in French fries by employing a temperature program during frying J Agric Food Chem 56(15):6162-6

Park DK et al – 2006, Microbial inactivation by microwave radiation in the home environment J Environ Health 69(5):17-24

Quan R et al – 1992, Effects of microwave radiation on anti-infective factors in human milk Pediatrics 89(4 Pt 1):667-9

Watanabe F et al – 1998, Effects of Microwave Heating on the Loss of Vitamin B(12) in Foods J Agric Food Chem 46(1):206-210

Yuan Y et al – 2007, A comparative study of acrylamide formation induced by microwave and conventional heating methods J Food Sci 72(4):C212-6


The physical principles of the microwave oven is quite simple: in the microwave oven an electronic tube, the magnetron, generates an alternating power field. The molecules within the food – especially the polar water molecules, but also amino acids, lipids and proteins – are forced to align themselves with the rapidly changing alternating electrical field. They oscillate around their axis in response to reversal of the electric field that occurs up to 5 billion times per second. This oscillation creates considerable intermolecular friction that results in the generation of heat. Thus, the food is heated from the inside outwards leaving the dishes and the oven itself cold, because they are not directly heated by microwaves.

In the western part of the world the detrimental effects of microwaves on biological systems have at least been known since their first application during the last world war. Russian scientists had already conducted research in the 1930s on the effects of microwaves on the nervous systems of humans and animals. Their findings led to very strict safety measures which, however, were not taken seriously by western scientists who in the 1960s still used threshold values a thousand times higher than those of the Russians. In the late 1980s a study on domestic microwave ovens was conducted in Washington D.C. as well as in two other states. It revealed that microwave emission during the thawing, cooking and grilling processes was one quarter higher than the official threshold value of 10 mW/cm2 laid down by the electrical industry. A product test revealed that 24 out of 30 of the tested microwave ovens were considered too dangerous and had to be withdrawn from the market. Microwave emission of these ovens reached values of up to 20 mW/cm2. A hearing of the American Senate Committee started a controversy between science and the industry on the safety of cooking with microwaves which still continues. The largest manufacturer of microwave appliances, the Raytheon Company, assured the committee that all their devices were fitted with ample safety measures, and furthermore it were “in any case clear that microwaves, unlike X-rays, don´t have a cumulative effect.” However, a renowned university professor sent the following statement to the committee:

“We have proven beyond doubt that microwaves hitting the eye have the following damaging effect: repeated short microwave radiation which in itself is not painful and shows no ill effects in the beginning, leads in the case of frequently repeated exposure to lasting eye damages. Thus this non-ionizing radiation has a dangerous cumulative effect.” [1]

Scientists declare that the quantum energy of microwave radiation is some orders of magnitudes less than required to dissociate covalent bonds and to trigger chemical reactions. It is therefore assumed that no chemical effects can be detectable in microwaved nutrients. Thus, according to scientific research, proteins, fatty acids, vitamins, etc. are not changed. Nevertheless, histological studies with microwaved carrots and broccoli have revealed that the molecular structures of nutrients are deformed by high frequency reversal of polarity, even up to the point of destroying the cell walls, whereas in conventional cooking the cell structures remained intact [3]. Microwaving may even result in the development of new, hitherto unknown substances. The microwave induced reversal of the polarity causes the cells of the nutrients to become destructively polarized, thus free radicals can be created. All radicals have a strong tendency to cause reactions.

In addition, through induction the food itself becomes a carrier and secondary source of technically generated radiation. Studies regarding the luminous power of luminescent bacteria revealed a highly significant association between the amount of microwave energy in the test foods and the increased energy in the blood serum of test persons who ate that food. The luminous power of luminescent bacteria exposed to serum from these test persons was significantly greater than that exposed to serum of those persons who had eaten conventionally heated food or raw food, respectively. This led the authors to the conclusion that such technically derived energies may be passed along to man inductively via ingestion of microwaved food [4, 5].

In a report published in 1980 by the Institute of Radiation Hygiene of the German Federal Office of PubIic Health (BGA) 16 studies were comparatively evaluated with regard to thermic and non-thermic effects of microwave radiation [6]:

  • Decrease in enzyme activity and influence on enzyme catalyzed processes;
  • Influence on the thyroid gland, suprarenal gland and their hormones;
  • Effect on composition and function of blood components respectively;
  • Influence on cell growth, and structural changes in chromosomes;
  • Cataract;

Influence on concentration, blood constituents, and hormones in the brain respectively. At the end of the 1970s, a Forensic Research Document was released in the United States containing alarming findings on the destruction of the nutritive value of foods, development of cancer-causing agents, and direct biological effects of exposure to microwave emissions on humans (Microwave Madness – The Truth Campaign magazine no. 2 p.16-17).

Established science has yet to prove that no qualitative changes take place in irradiated matter, e.g. impede the characteristic vital-energy field, as was probably the case in the experiment with the germination of grain. An interesting research method was published by Le Laboratoire associatif pour I´application des tests sensibles (LAPATS). A special crystallization method for test-suspensions makes it possible to draw conclusions as to the kind and origin of food-substances, e.g. biological or conventional production, irradiated or not, and the heating method used. The crystallization method reveals that food becomes denatured through irradiation. Microwaved milk was denatured to such a degree that it was not considered fit for consumption.

A group of scientists at the Stanford University School of Medicine in California discovered that microwaving breast milk at high temperatures (72°C to 98°C) caused a marked decrease in activity of all the tested anti-infective factors. E. coli growth at >98°C was 18 times that of control human milk. Microwaving at low temperatures (20°C to 53°C) had not significant effect on total IgA, but did significantly decrease lysozyme. Even at 20°C to 25°C, E. coli growth was five times that of control human milk. Because microwave radiation lead to a significant loss of the immunological properties of milk the authors concluded that microwaving is definitely “not a suitable heat treatment modality.” They assumed that non-thermal as well as thermal effects of microwave radiation must play a decisive role because “the adverse effects on anti-infective factors are difficult to explain on the basis of hyperthermia alone.” [10]

A further study on milk, conducted in Vienna, showed that microwave treatment induced high razemization rates in food proteins which was not observed after conventional cooking. In particular, D-proline and cis-D-hydroxyproline were reported to have been found in significant amounts in microwave-heated infant milk formulas. Normally, L-proline is found in biological matter. Lusec et al. [11] warned that “the conversion of trans to cis forms could be hazardous because when cis-aminoacids are incorporated into peptides and proteins instead of their trans isomers this can lead to structural, functional, and immunological changes.” Moreover, in animal experiments D-proline was found to be neurotoxic. Renowned scientists did their utmost to discredit these findings. Shortly afterwards the Nestle Research Centre declared food microwaving “as good as and some times better than the conventional heat treatments.” In fact, Lubec himself “revoked” his findings in 1990, yielding to pressure from industry and trade.

On 28 January 1992, during a TV interview in Kassensturz and in front of the press, Prof. Blanc [former member of the University Institute for Biochemistry, Swiss Federal Institute of Technology (ETH) Lausanne] formally disassociated himself from his earlier interpretation of the results of the research he had done together with Dr. Hertel. Although, in February of 1992 he had admitted in an interview with the Basler Zeitung: “This doesn´t mean that no further research should be conducted because the changes in the blood do indicate that irradiated food causes a reaction in the body.” However, in a private letter to Dr. Hans U. Hertel, the co-author, he admitted that he feared consequences and that the safety of his family was more important to him than anything else.

Seldom has a report caused such a stir as did the Swiss study on the hazards of microwaved food. Journalists, microwave opponents, trade, and industry started a battle which is still in full swing today. The Swiss Association for Electroapparatuses for Households and Industry (FEA) filed a complaint against Dr. Hertel for violating the Law Against Unfair Competition. The court upheld the complaint and sentenced Dr. Hertel.


(From In the journal Pediatrics (vol. 89, no. 4, April 1992), there appeared an article titled, “Effects of Microwave Radiation on Anti-infective Factors in Human Milk”. Richard Quan, M.D. from Dallas, Texas, was the lead name of the study team. John A. Kerner, M.D., from Stanford University, was also on the research team, and he was quoted in a summary article on the research that appeared in the 25 April 1992 issue of Science News.

To get the full flavour of what may lie ahead for microwaving, here is that summary article: “Women who work outside the home can express and store breast milk for feedings when they are away. But parents and caregivers should be careful how they warm this milk. A new study shows that microwaving human milk-even at a low setting-can destroy some of its important disease-fighting capabilities.

“Breast milk can be refrigerated safely for a few days or frozen for up to a month; however, studies have shown that heating the milk well above body temperature-37&degree;C-can break down not only its antibodies to infectious agents, but also its lysozymes or bacteria-digesting enzymes.

So, when paediatrician John A. Kerner, Jr, witnessed neonatal nurses routinely thawing or reheating breast milk with the microwave oven in their lounge, he became concerned. “In the April 1992 issue of Pediatrics (Part I), he and his Stanford University co-workers reported finding that unheated breast milk that was microwaved lost lysozyme activity, antibodies and fostered the growth of more potentially pathogenic bacteria.

Milk heated at a high setting (72 degree;C to 98 degree;C) lost 96 per cent of its immunoglobulin-A antibodies, agents that fend off invading microbes. “What really surprised him, Kerner said, was finding some loss of anti-infective properties in the milk microwaved at a low setting-and to a mean of just 33.5degree;C.

Adverse changes at such low temperatures suggest ‘microwaving itself may in fact cause some injury to the milk above and beyond the heating.  Stanford University Medical Center no longer microwaves breast milk, Kerner notes.

Journalist Tom Valentine, after chasing this story, found it interesting that ‘scientists’ have so many ‘beliefs’ to express rather than prove fact. Yet facts eventually snuff out credential-based conjecture. Researcher Quan, in a phone interview, said that he believed the results of research so far warranted further detailed study of the effects of microwave cooking on nutrients.

The summary sentence in an abstract of the research paper is very clear: “Microwaving appears to be contra-indicated at high temperatures, and questions regarding its safety exist even at low temperatures.” The final statement of the study conclusion reads:”This preliminary study suggests that microwaving human milk could be detrimental. Further studies are needed to determine whether and how microwaving could safely be done.”

Unfortunately, further studies are not scheduled at this time. If there are so many indications that the effects of microwaves on foods can degrade the foods far above the known breakdowns of standard cooking, is it not reasonable to conduct exhaustive studies on living, breathing human beings to determine if it’s possible that eating microwaved foods continuously, as many people do, can be significantly detrimental to individual health?

Yet the microwave-oven industry had only to prove that the dangerous microwaves could, indeed, be contained within the oven and not escape into the surrounding area where the radiation could do damage to people. The industry must admit that some microwaves escape even in the best-made ovens. So far, not one thought has been given by the industry to the possibility that the nutrients could be so altered as to be deleterious to health.

Valentine published the results of this study in Search for Health in the Spring of 1992. But the follow-up information is available only in a later edition, and also in Acres USA.

(From How do microwave ovens work? (#2)

Microwaves are a form of electromagnetic energy, like light waves or radio waves, and occupy a part of the
electromagnetic spectrum of power, or energy. In our modern technological age, microwaves are used to relay long
distance telephone signals, television programs, and computer information across the earth or to a satellite in space. But
the microwave is most familiar to us as an energy source for cooking food. Every microwave oven contains a magnetron, a tube in which electrons are affected by magnetic and electric fields in such a way as to produce micro wavelength radiation at about 2450 Mega Hertz (MHz) or 2.45 Giga Hertz (GHz). This microwave radiation interacts with the molecules in food.
All wave energy changes polarity from positive to negative with each cycle of the wave. In microwaves, these polarity
changes happen millions of times every second. Food molecules – especially the molecules of water – have a positive and
negative end in the same way a magnet has a north and a south polarity.

In commercial models, the oven has a power input of about 1000 watts of alternating current. As these microwaves
generated from the magnetron bombard the food, they cause the polar molecules to rotate at the same frequency millions
of times a second. All this agitation creates molecular “friction”, which heats up the food. This unusual type of heating also causes
substantial damage to the surrounding molecules, often tearing them apart or forcefully deforming them.
By comparison, microwaves from the sun are based on principles of pulsed direct current (DC) that don’t create frictional
heat; microwave ovens use alternating current (AC) creating frictional heat.
A microwave oven produces a spiked wavelength of energy with all the power going into only one narrow frequency of
the energy spectrum. Energy from the sun operates in a wide frequency spectrum.

Scientific evidence and facts

In Comparative Study of Food Prepared Conventionally and in the Microwave Oven, published by Raum & Zelt in 1992,
at 3(2): 43, it states
“A basic hypothesis of natural medicine states that the introduction into the human body of molecules and energies, to
which it is not accustomed, is much more likely to cause harm than good. Microwaved food contains both molecules and energies not present in food cooked in the way humans have been cooking food since the discovery of fire. Microwave energy from the sun and other stars is direct current based. Artificially produced microwaves, including those in ovens, are produced from alternating current and force a billion or more polarity reversals per second in every food molecule they hit.
Production of unnatural molecules is inevitable. Naturally occurring amino acids have been observed to undergo isomeric
changes (changes in shape morphing) as well as transformation into toxic forms, under the impact of microwaves
produced in ovens.

This article goes on and on.  S.

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