Food irradiation: why and why not

Ronald L. Kathren, Dir. U.S. Transuranium/Uranium Registries ,WSU College of Pharmacy

Preservation and protection of food by irradiation is a controversial subject and recently has been the subject of much media attention. Thus it might be appropriate to examine the whys and why nots of food irradiation. The 'why not' part is relatively easy: As a scientist, I have been unable to come up with any cogent or rational basis, scientific or otherwise, for opposing food irradiation. On the other hand, there are numerous 'whys' that speak to its immediate application and benefit to the public health.

Claims to the contrary notwithstanding, food irradiation offers great potential benefit to the consumer with no demonstrable risk. The technical feasibility of preservation of many foods by irradiation has been fully established. Indeed, food irradiation offers a practical, safe, and economical method of food preservation not only to the American public, but to lesser developed countries lacking readily available refrigeration and other modern preservation methods, and the levels of sanitation enjoyed in the United States.

Proper irradiation of food neither destroys nutritional quality nor adversely affects taste or texture. To this I can speak from personal experience, having eaten on more than one occasion food that had been preserved by irradiation. I could not tell by appearance, taste, or texture that the food had been subjected to radiation preservation, and I clearly suffered no ill effects. My experience was exactly the same as that of our astronauts, whose food is preserved by irradiation.

Opposition to food irradiation is in a sense deja vu, reminiscent of opposition to such now institutionalized public health measures as pasteurization of milk and chlorination of water. When pasteurization was first introduced, numerous objections were raised. These included claims that the nutritional quality of the milk was adversely affected through destruction of Vitamin C and other vitamins that had not yet been discovered. There was little merit in these claims, although there was a minor basis in fact. Pasteurization does in fact destroy much of the Vitamin C in milk, but milk is not a primary dietary source of this vitamin. As for vitamins not yet discovered, their discovery still awaits us. In the meanwhile, pasteurized milk has been instrumental in virtually eliminating milk-borne diseases such as brucellosis and tuberculosis of the bones and joints in the United States and other advanced nations.

Similar objections have been raised with respect to chlorination of water. After all, so goes the argument, chlorine is a toxic element; it was even used as a war gas in World War I with great loss of life and considerable infliction of disability and suffering. Again a factual basis, but one totally irrelevant to the problem at hand; in the concentrations used for water purification, chlorine has been demonstrated to be without toxic effect to humans. Indeed, the benefits of chlorination of water are apparent even to school children and include the virtual elimination of water-borne diseases such as typhoid in the United States and other advanced nations. This single public health measure has added years to the longevity of Americans.

Which brings us back to food irradiation. For at least four decades, numerous studies have been carried out to assess the palatability and wholesomeness of irradiated food, and to determine the presence of toxic agents resulting from irradiation. These have included lifetime feeding studies in animals, in some studies through several generations, and organaleptic tests in humans. These studies have consistently shown irradiated foods to be toxicologically safe, wholesome, and palatable. That irradiation produces free radicals and small amounts of certain compounds in foods is unequivocally correct, and is often used as the scientific rationale against food irradiation. But it is also unequivocally correct that the types and amounts of compounds produced by irradiation do not impart toxic or hazardous properties to the foodstuff. Indeed, every food processing procedure, including (and perhaps especially) cooking, induces some sort of chemical change. In the case of cooking, these changes are desirable, but they may also destroy vitamins or otherwise diminish the nutritional content of the food, affect the taste, and, yes, even produce small amounts of toxic byproducts. Yet I know of no rational scientist or lay person who opposes cooking or, in the processing realm, retorting of canned food, a process that provides protection against anaerobic bacterial food poisonings while at the same time cooking and inducing much chemical change in the foodstuffs so treated.

Food irradiation can not only be used as an adjunct to or in lieu of other sanitation measures, it also can be used where no other practical sanitation measures exist. It is effective against a wide variety of microorganisms associated with food poisoning illness and even death. These include the deadly Clostridium botulinus and species and strains of Salmonella, Staphylococcus, Streptococcus, Vibrio, Listeria and Campylobacter, to name the more prominent ones. It is also effective against Trichina parasites in pork, and has been demonstrated in laboratory research to control viruses such as hepatitis and poliomyelitis. Perhaps even more significantly, irradiation is an effective way to control insect pests in stored grain. Irradiation also can be used to reduce cooking time of some foods, retard sprouting in potatoes and root crops, and to delay ripening of harvested fruits and vegetables, allowing more time for marketing.

Thus, an important why in favor of food irradiation is that it has the potential to greatly reduce, if not eliminate, many of the estimated 10 or more million food poisoning cases that occur annually in the United States alone, and to save many lives in the process. Were irradiated hamburger de rigueur, those fast food hamburger illnesses and deaths from E. coli would never have occurred. And a number of persons who ate Vibrio vulnificus-contaminated shellfish from Florida would be alive and well today instead of dead from this virulent microbial contaminant.

In addition to providing protection against food-borne diseases, food irradiation is an effective means of retarding spoilage, thereby reducing losses of foodstuffs and making available for the table more of what we produce. Globally, losses of agricultural foodstuffs are staggering; the United Nations Food and Agricultural Organization estimates that about 25% - fully one fourth of the total worldwide food production - is lost to pests and microorganisms. Most of this loss could be controlled by food irradiation, thereby effectively increasing the quantity of usable foodstuffs without planting any more acreage or using more artificial fertilizers. The potential economic benefit is staggering, as is the potential human benefit through increased availability of nutritionally necessary foodstuffs.

In addition to control of food-borne diseases, food irradiation can also accomplish other desirable societal and public health objectives. By increasing the shelf life of foodstuffs, irradiation can reduce the requirement for chemical additives to retard spoilage and control pests. Products sterilized by irradiation do not require refrigeration - a boon to parts of the world where refrigeration capabilities are limited or absent, and, on a more mundane level, to campers and hikers. And, reducing the need for refrigeration carries with it more subtle benefits: energy conservation because we simply will not have to manufacture or operate as much refrigeration equipment, and reduced use of potentially environmentally degrading chemicals, including chlorofluorohydrocarbons used in refrigeration.

And so, the basic reasons supporting food irradiation: It is effective, safe, inexpensive, and like the Starship Enterprise, it goes where other methods cannot go. Its application brings not only large economic benefits, but enormous societal benefits through reduction or even elimination of food-borne illness, and more efficient utilization and increased supply of available foodstuffs.

Having examined the case for and against food irradiation - the why and why not - it is clear that food irradiation provides an effective means of ensuring the safety of our foodstuffs, of increasing the quantity of food available to the world, and reducing food prices to the consumer. It is safe and technologically and economically feasible. It is incomprehensible to me, and in my view at least, both scientifically and morally reprehensible that we do not utilize the full potential of food irradiation for the benefit of mankind.

Return to title page April 1998 Agrichemical and Environmental News