In a study just published in the
Proceedings of the National Academy of Sciences, scientists from the University of Wisconsin-Madison (UW-Madison) report on cats developing severe neurological symptoms due to a degradation of myelin, the fatty insulator of nerve fibers called axons. Because myelin facilitates the conduction of nerve signals, when it is lost or damaged there can be impairment of sensation, movement, thinking and other functions, depending on what particular nerves are affected. This loss of myelin is found in several disorders of the central nervous system in humans -- the best known being multiple sclerosis (MS).
So what caused the cats to develop neurological problems? Although the researchers' statement to the media practically buries the fact, a close read shows the animals were fine until fed irradiated food. What's more, when they were taken off the irradiated diet, the animals' nervous systems began healing.
The new study took place when the researchers were faced with reports of a mysterious illness in pregnant cats. A commercial company had been testing various diets on the animals to see how the food impacted growth and development in the felines. The food used, it turns out, had been irradiated. Irradiation, which is approved by the U.S. Food and Drug Administration (FDA) for many human as well as animal foods, involves exposing foods briefly to a radiant energy source such as gamma rays or electron beams in order to kill bacteria.
Some of the cats eating the irradiated cat food exhibited very severe neurological symptoms, including movement disorders, vision loss and even paralysis. "After being on the diet for
three to four months, the pregnant cats started to develop progressive neurological disease," said Ian Duncan, a professor of medical sciences at the UW-Madison School of Veterinary Medicine and an authority on demyelinating diseases, in a statement to the media.
The sick cats were shown to have widely distributed the very severe demyelization of the central nervous system. Their neurological symptoms were very much like those seen in people with MS and other demyelization disorders. When the felines were taken off the irradiated foods, they began to recover slowly. However, according to Dr. Duncan, the restored myelin sheaths were no longer as thick as normal myelin sheaths.
The finding is important, the scientists concluded in their study, because it shows the central nervous system retains the ability to reestablish myelin -- so strategies that could be developed to spur the growth of new myelin sheaths anywhere nerves themselves are preserved could be a possible therapy for treating a host of severe neurological diseases in humans. "The key thing is that it absolutely confirms the notion that remyelinating strategies are clinically important," Duncan stated.
Curiously, although the scientists' related their findings to possible human applications, they were quick to dismiss a possible connection between people, irradiated food and health risk. "We think it is extremely unlikely that (irradiated food) could become a human health problem," Duncan explained in the media statement. "We think it is species specific."
However, not everyone agrees irradiated food is fine for humans or animals. According to the Center for Food Safety, studies have shown
irradiation produces volatile toxic chemicals such as benzene and toluene, which are known or suspected to cause cancer and birth defects. A 2001 study found an association between colon tumors and 2-alkylcyclobutanones (2-ACB's), a new chemical compound detected only in foods that have been irradiated.
For more information: [Link]
in Australia and New Zealand. Makes you wonder. Here is what they say on their official site [Link]
"Food irradiation
Food irradiation is a food preservation process and a quarantine measure. Food processors use it to destroy bacteria that cause food decomposition and food poisoning. Those bacteria include the parasites, moulds and yeasts that spoil food, and salmonella and campylobacter that cause illness.
Food can only be irradiated if there is no other safe method available. Any irradiated food must go through a strict safety assessment by Food Standards Australia New Zealand and, if approved, must be labelled as having been treated by radiation.
To date, in Australia and New Zealand, only herbs and spices, herbal teas and some tropical fruits have been approved to be irradiated.
Food irradiation is a food processing technology that exposes food to a source of ionising energy to purify it. Under the Food Standard covering the irradiation of food in Australia and New Zealand, this energy can be in the form of gamma rays from Cobalt 60, machine generated X-rays, or an electrically generated electron beam. "