Dear Dr Fox: There is no evidence that irradiation of foodstuffs makes the food toxic, as you claim in your June 20 column. Our astronauts eat irradiated food for safety reasons. -- John A. Melson, M.D., Medford, Oregon
Dear J.A.M.: On the contrary, dear doctor, there is much evidence that food irradiation can both lower the nutrient value of foods and cause serious health problems for some animals, notably cats. While astronauts are not cats, I think they would fare better in space (where I do not believe humans have a right to invade until we heal our own planet) on reconstituted freeze-dried foods, as well as sprouted and fermented foods -- primarily plant-based and highly nutritious.
As for irradiated food for pets, the Organic Consumer Association (organicconsumers.org) notes: "The FDA based its approval of irradiation to treat meat products on only five animal studies of 441 studies submitted, and these five either showed health effects or had obvious scientific flaws. In fact, animal studies have shown many health effects, such as tumors, kidney failure, death of offspring and miscarriages."
Laboratory animal tests of the effects of irradiated food have reported embryonic deaths, lower offspring survival and internal bleeding. Irradiated foods contain novel free radicals and other compounds with the potential to cause mutations and cancer, and the process can damage essential nutrients in the food.
The government may also be under pressure from food manufacturers to ignore concerns over irradiation technology. The meat industry, in particular, wants it approved in the U.S. because of continued problems with bacterial contamination and costly recalls that follow outbreaks of food-borne illnesses.
New Zealand news organization Stuff reports, in a story by Eugene Bingham: "A veterinary specialist who discovered a connection between irradiation of pet food and deaths in cats is calling for a ban on the process for animal food. Dr Georgina Child made a link between batches of cat food treated with gamma irradiation and the deaths and neurological damage to dozens of cats in Australia in 2009.
"'It was one of the saddest episodes I have seen in my career as a neurologist and one that was very difficult to attract attention to at the time -- and I hope I never see the equivalent again,' says Child, a veterinary neurologist based in Sydney, Australia. 'More than 35 cats died or were euthanized and many others had permanent neurologic deficits.' ... After the cat food scare, Biosecurity Australia required irradiated dog food to carry a warning that it shouldn't be fed to cats." (Full story: stuff.co.nz, 5/21)
In another story on this same incident, Edie Lau of the Veterinary Information Network reported that all the cats in question "had eaten an imported dry diet, sold under the brand name Orijen and made in Canada by Champion Petfoods. The food was subject to gamma irradiation upon entry to Australia at levels greater than or equal to 50 kilo-Grays (kGy). The U.S. Food and Drug Administration also allows animal feed, including pet food and treats, to be irradiated up to 50 kGy. By comparison, most human foods in the United States allowed to be irradiated are limited to levels of 30 kGys and below. Packaged meats for astronauts are an exception; those may be treated up to 44 kGy. The FDA requires all irradiated foods to be labeled as such; Australia does not require labels on irradiated pet food.
"Symptoms in the Australian cats first appeared three to six months after they were exposed to the dry food, Child said. Some had eaten the food for as few as three weeks; others for more than six months," VIN reported. "Most of the cats were fed other foods as well. The affected cats ranged in age from less than 1 year to 15 years. Early signs of illness included a wobbly gait, unwillingness to jump onto sofas or beds, and loss of balance -- exhibited, for example, by falling off tables, according to a Q&A for consumers prepared by Champion Petfoods. ... But even patients who are paralyzed and lose vision as a result of eating irradiated food can fully recover, given sufficient time, nursing care and food that hasn't been irradiated, said Dr. Ian Duncan, professor of neurology at the University of Wisconsin-Madison School of Veterinary Medicine." (Full story: news.vin.com)
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