The dangers of microwaving food

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The majority of us will gladly "nuke" our meals on a regular basis. But it may be time to end our love affair with the microwave. Cooking on the run Throughout its 40-year history as a commercial product, the microwave oven has been steeped in controversy. Indeed, the "slow food" movement is in part a response to the microwave oven and everything it stands for: fast-paced lifestyle, eating on the run, the lack of interest in healthy foods and in the meal itself as an "occasion". The first household microwave, the Amana Radarange, was introduced in 1967 and the debate over its health effects has raged since. Why food tastes different Traditional sources of cooking use waves of infrared frequency to heat food. This form of cooking heats the food from the outside in, and treats the food gently -- more or less shaking the molecules until the desired "done" state is reached. Microwaves are different. Its frequencies can only heat certain molecules, water being one of them. All food molecules (including water) have a positive and negative end in the same way a magnet has a north and south polarity. The microwave radiation scrambles the positive and negative, flipping them back and forth millions of times in the space of a few seconds. This rapid switching makes the food molecules speed up and all this agitation creates friction, heating the food from the inside out. But such high, rapid scrambling damages the actual food molecules, tearing them apart or deforming them, changing the taste and texture in sometimes unpleasant ways. Soviet research Russia was one of the few countries that did not embrace the microwave oven. In fact after doing their own research on the biological effects, Russia outlawed microwaves in 1976 and issued an international warning. Their concerns centred around the decrease in nutritional B-complex vitamins, vitamin C, vitamin E, essential minerals, lipotrophics, and nucleoproteins. But they also looked at chemical alterations within the food that converted amino acids found in milk and cereal into carcinogens and found a link between microwave use and an increase in stomach and intestinal cancers. The ban lifted after the Soviet Union collapsed in 1990. Swiss research In 1989, the Swiss food scientist Dr. Hans Ulrich Hertel found that eating microwaved food, over time, causes a decrease in blood haemoglobin, a decrease in HDL (good) cholesterol, and a decrease in white blood cell count. The implications are that prolonged eating of microwaved food can cause anemia, heart disease, a compromised immune system, degenerative diseases and cancer. Hertel was promptly convicted of interfering with commerce and the report was suppressed by a powerful trade group until 1998, when the European Court of Human Rights lifted the gag order. Spanish research A study published in the Journal of the Science of Food and Agriculture in 2003 by researchers from the Spanish scientific research council CEBAS-CSIC found that cooking by microwave lowers the nutritional value of vegetables. According to Dr. Cristina Garcia-Viguera, co-author of the study, microwaved broccoli loses 97 percent, 74 percent and 87 percent of the three major cancer-protecting antioxidant compounds (flavonoids, sinapics and caffeoyl-quinic derivatives). By comparison, steamed broccoli loses 11 percent, 0 percent and 8 percent of the very same antioxidants. This contradicted the FDA statement that "foods cooked in a microwave oven may keep more of their vitamins and minerals, because microwave ovens can cook more quickly and without adding water". American research Since then the FDA has revised its stance on microwaves and released several warnings about microwaves and food. The most recent is about PFOA (perfluorooctanoic acid) being served up to unwitting consumers via bags of microwave popcorn. Radiation leaks aside from damaged door seals are also a concern along with uneven cooking creating cold spots in which bacteria can thrive. You should also avoid heating plastics in the microwave or using plastic wrap as this can cause the chemical BPA to leak into your food. Ceramic or glass dishes are safer. [Editor's note: read more about plastic and the microwave in our article What you need to know about plastics and your food.] Still want that nuked cup of coffee? Joyce Nelson is an environmental journalist based in Toronto.