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North America’s obsession with the oh-so-quick and convenient microwave may be pushing us from the frying pan into the fire. An estimated one out of every two households has a microwave oven. Modern cookbooks abound with recipes for cooking with this handy device. Yet an increasing body of evidence is calling into question the safety of one of our favourite kitchen appliances.

History of the Microwave

Microwave ovens were introduced into the market for domestic use in the early 1970s. At that time, they were considered relatively safe if properly cleaned and with door seals well maintained to prevent leakage. There was but a hint that their safety and the nutritional values of microwaved foods weren’t what the public believed. However, in 1989, Dr. Hans-Urich Hertel, a Swiss food scientist, and professor Bernard Blanc of the Swiss Federal Institute of Technology began conducting extensive research on the effects of microwaved food on humans. Using a carefully controlled protocol, nine people, including Dr. Hertel, were alternately exposed to microwaved and conventionally cooked foods from organic sources. Samples of participants’ blood were taken right before eating and at certain intervals after eating.

Researchers found that after microwaved food consumption, there was significant reduction of all blood hemoglobin and cholesterol values (both good HDL cholesterol and bad LDL cholesterol), and that bad cholesterol levels were elevated relative to good cholesterol levels.

Lymphocyte (white blood cell) activity decreased notably after ingestion of microwaved foods compared to that of non-treated foods. When exposed to blood from those who had eaten microwaved foods, bacteria that glow when examined under a special light glowed much brighter than when exposed to blood samples from those who had eaten non-treated food. This established an association that energy from microwaved foods may be passed on to those who consume the food.

Free Radical Effects

There were non-thermal effects that altered cell membrane permeability, making cells susceptible to invasion by bacteria, fungi and viruses. Other adverse effects included the change of cells from a healthy aerobic (oxidation) status to an unhealthy anaerobic (fermentation) condition. Anaerobic cells produce damaging free radicals such as hydrogen peroxide and carbon mono-xide, which increase the need for neutralizing antioxidants in the body such as vitamins A, C, E and selenium.

Dr. Hertel holds that when food is microwaved, the oven exerts a massive power input that destroys and deforms food molecules and produces new “radiolytic” compounds unknown in nature. Exposing food to ionizing rays such as gamma or X-rays (irradiation) creates URPs (unique radiolytic products) in the food. URPs have free-rad-ical capabilities that destroy healthy cells and contribute to abnormal growth, a cause of cancer. Conventional wisdom has contended that microwaves are non-ionizing. Dr. Hertel’s evidence would appear to contradict that notion.

Decreased Nutritional Value

Other problems reported with microwaved foods include the destruction of nutritional value of meat proteins, lowered metabolic activity of important plant substances such as alkaloids, glucosides, galctosides and nitrilosides, and reduced bioavailability of certain vitamins and minerals, which affects the body’s ability to absorb these nutrients.

Pediatrics (1992; 89: 667-9) reported heating or thawing human milk at low temperatures of 20 to 53 degrees Celsius reduces the level of infection-fighting factors in milk. Another study found microwaving milk at temperatures in excess of 72 C caused a significant decrease in all of its infection-fighting factors. The authors strongly objected to the use of microwaved human milk in hospitals.

The Journal of Natural Science (1998; 1: 2-7) reported a Tulsa, Oklahoma, patient who died of anaphylactic shock as a result of a transfusion of blood warmed in a microwave. Microwaves appeared to have altered the blood sufficiently to cause the death of the patient.

A study published in Lancet (1989; 913: 92-3) demonstrated high rates of change in microwaved food proteins not seen with conventional cooking. The authors warned that such effects on amino acids could be hazardous and “can lead to structural, functional and immunological changes.”

Croft Woodruff, MH (Hon.), vitamin retailer, nutrition counsellor and health activist for EDTA chelation therapy, founded and co-hosted the longest-running alternative health radio program in Vancouver. Phone: 604-327-3889. E-mail: croft@cwhealth.com

Source: alive #249, July 2003