Would You—Should You—Do You--Eat Irradiated Food?

Radura A cheerful, optimistic scientist took me on a tour of his research lab, where he housed many lively chickens, all of whom seemed to be thriving on a diet of irradiated food.  They’d been eating it for about 2 years and were in good health and producing normal offspring.  I left the lab thinking that irradiated food—with almost no pathogens and a longer shelf life than untreated food—would be the wave of the future.  At that time, I was a student journalist at the University of Michigan (in Ann Arbor). The year was 1954.  Now, more than 50 years later, less than 1% of the food Americans eat is irradiated. Would we be better off if that percentage were higher?  If so, why are we shying away from this technology?  I asked our site’s Advisory Board scientists, as well as my computer, the answers to these and related questions. Their responses follow.


What is food irradiation?


 It’s a process by which foods that are approved for the procedure are briefly exposed to a controlled amount of radiant energy, primarily in order to kill germs and extend shelf life.  There are three ways this can be done: with gamma rays, electron beams, and x-rays.  The FDA has found this technology to be safe.  No matter which method is used, there is no chance that the food will become radioactive. The food does not come into direct contact with radioactive material, only with its energy.  “For example, when the source of an electron beam is shut off, the energy disappears,” explains food scientist Dr. Catherine Cutter. (For details about the irradiation process, click here.)


What are the benefits of subjecting food to irradiation?


-  According to the USDA, “Irradiation is an important food safety tool in fighting foodborne illness.” Irradiation reduces (to almost zero) the numbers of germs that may be present in food. When astronauts are traveling in space, they are given only irradiated food to be sure that they do not develop foodborne illnesses.  Hospitals sometimes serve irradiated food to patients with a compromised immune system.  Irradiation could be an especially valuable tool for protecting public health now that there is life-threatening danger from some antibiotic-resistant bacteria that have been found in contaminated food. Irradiation could eliminate the risk of Listeria from hot dogs and deli meats and the risk of Salmonella in animal feed and grains.  It would be a smart precaution for people with weakened immune systems to switch to irradiated meat, poultry, and produce if irradiated versions of these foods were easily available and not too costly.


-  “Rare meat and even steak tartare (raw ground beef) would be much safer to eat if it had been irradiated,” says food scientist Dr. Karin Allen.  Irradiation at the slaughter plant could eliminate bacteria commonly found in these animal products, says the CDC. 


-  Like freezing, canning, and drying, irradiation can extend the shelf life of foods.  It can reduce spoilage, inhibit ripening, and slow down sprouting. (Spoilage is caused by bacteria that ruin the taste, smell, and/or appearance of food.)  According to food scientists at Clemson University, “Irradiated strawberries stay unspoiled in the refrigerator for up to three weeks as  compared to three to four days for untreated strawberries.” Irradiation also slows down the sprouting of potatoes.


Irradiation could eliminate insect pests and thereby replace fumigation with toxic chemicals that are routinely used on many foods now. 


   What are the limitations of irradiation?


Although irradiation kills most bacteria, parasites, insects, and fungi, it does not kill bacterial toxins which cause botulism. However, studies have shown that spoilage organisms (which make food taste, smell, and/or look bad) should alert consumers to discard the food before these toxins can develop.  “Viruses are, in general, resistant to irradiation at doses approved for foods,” says the CDC.  Irradiation is also ineffective on BSE (commonly called mad cow disease).   


Could I be using irradiated products without knowing it?


Irradiated food sold directly to consumers (and there is very little of this in the U.S.) must be labeled with the international symbol called a “radura” (see photo) and the words “treated with radiation” or “treated by radiation.”


A few stores have sold irradiated food since the ‘90s. A few restaurants have offered it.  However, consumers who want to purchase it may have a hard time finding any.  Therefore, your consumption of irradiated products is probably limited to spices and dried herbs. Many are irradiated. No symbol or wording is required on the container.  Food process engineer Timothy Bowser explains why spices and herbs are commonly irradiated: “They are known to contain heavy levels of contamination, and they can be difficult to clean. (You can’t effectively wash a cinnamon stick in water without ruining it, and chemical treatments have many issues.) Spices are grown largely outside of the U.S., where they may be exposed to unsanitary handling.”  Note: irradiation is not allowed on organic herbs and spices. McCormick uses ethylene oxide gas rather than irradiation. 


Though most consumers don’t know this, irradiation is used on many non-edible drugstore items, such as band-aids, eye drops, and feminine hygiene products.


Are there any health risks from irradiating food?


Government organizations and the scientists on our Advisory Board do not believe that there is any significant risk from irradiated food, irradiation facilities, or the nuclear waste resulting from the process.  The morbidity and mortality from contaminated food is of far greater concern than any risks from irradiating food.  Animal studies lasting several generations have been performed on several species (including mice, rats, and dogs) with no evidence of harm to the subjects.


Food process engineer Dr. Tim Bowser discusses the safety of the irradiation facilities: “I believe that the risks are minimal because the industry has a long history, and they have been very careful to use huge safety factors in their designs. Also, amounts of radioactive materials are virtually insignificant when compared to a nuclear power plant.” Furthermore, the food given to astronauts on flights is irradiated to the point of sterilization, and no ill effects have been detected.


Does irradiation have any adverse effects upon the quality of the food?


The CDC says that, although irradiation slightly warms the food, it does only minimal damage to taste and nutritional value. Some consumers may notice a slight off-taste with some products.


Still, Dr. Bowser points out that there may be some disadvantages: “When ionizing particles or photons are properly applied to a food product, they can damage the DNA of a microorganism, ruining it beyond repair. (This is what we want to happen to pathogens and spoilage organisms.) Unfortunately, there are also effects on the food product. You might think of the irradiation process as shooting tiny laser beams into and through a food product. The lasers don’t do much to the food except perforate it and cause some physical damage, but if a bacteria living on the food was perforated or poked by the laser, it would cease to function properly and die. The question is this: is the physical damage to the food product tolerable for the advantage gained? In some foods (like dried spices and pet foods), I think so. However, I am convinced that irradiation is not an advantage for all food products.”   The CDC confirms this last point, saying that, for example, the quality of shellfish is severely damaged by irradiation.


What edible products have been approved for irradiation by U.S. governmental agencies?


Since 1963, many products have been approved including white flour, white potatoes, pork, tea, produce, herbs and spices, poultry, and meat.  However, products actually being irradiated for consumption in the U.S. are mostly spices and herbs, small amounts of meat and poultry, and pet food.


Why has irradiation had difficulty getting general acceptance in the U.S.?


Dr. Allen explains the two main reasons: fear and expense.  Food suppliers are reluctant to have their products irradiated because they believe consumer distrust—concern about safety—would keep them from buying these items.  Also, at the present time, irradiating products can be costly.  “It’s not the procedure itself that’s expensive,” says Allen.  “It’s the shipping involved.  There are only about 100 irradiator facilities in the U.S.  Sometimes food has to be shipped to one of these and then shipped back to the distributor.  Until there is more consumer demand and acceptance, it doesn’t pay for companies to irradiate food.”  At present, the cost is  passed on to consumers; irradiated ground beef costs 5-10¢  a pound more, says. Dr. Cutter.

Why is irradiation used more in other countries than in the U.S.?


In 37 countries, more than 40 foods are irradiated.  In some European countries, irradiation has been used for decades.  A list of countries using radiation includes the following: France, the Netherlands, Portugal, Israel, Thailand, Russia, China, and South Africa.  



Dr. Bowser feels there’s less need of it in the United States: “The U.S. has a very ‘clean’ food supply that comes from fields that are not fertilized or contaminated with human waste or sewage. We also have a fantastic food distribution system that is rapid and includes refrigeration. The U.S. also has well-developed and accepted methods of food product preservation (such as canning, dehydration, and freezing) that move irradiation to the fringe of consideration for mainstream product preservation.”


Will irradiated food be more available to consumers in the U.S. in the future?


Here is Dr. Bowser’s opinion: “I think the future of irradiation in the U.S. for human-consumed food is somewhat bleak. The catastrophe in Japan has delivered a global setback to irradiation and nuclear industry overall. [Other nuclear disasters have had this same effect.] On the other hand, irradiation is important in the medical/pharmaceutical industry and is quickly becoming important in the pet, animal, and zoo food industries.”


How can the American public encourage greater use of food irradiation?


Education may be the key.  According to the CDC, in marketing tests of specific foods, 50% of consumers indicated a willingness to buy irradiated food, and, when they were educated about the benefits of irradiation, the number of willing users rose to 80%.  If   enough consumers tell supermarket store managers, restaurant owners, food manufacturers and distributors, and members of Congress that they want irradiated food, it may eventually appear in more supermarkets and restaurants. 




Karin E. Allen, Ph.D., Utah State University, Dept. of Nutrition, Dietetics, and Food Sciences


Timothy J. Bowser, Ph.D., Oklahoma State University, Dept. of Biosystems and Agricultural Engineering


Catherine N. Cutter, Ph.D., Pennsylvania State University, Dept. of Food Science
cdc.gov (Centers for Disease Control and Prevention) “Food Irradiation”


clemson.edu (Clemson University Cooperative Extension) “Food Irradiation”


usda.gov “Irradiation and Food Safety, Answers to Frequently Asked Questions”


physics.isu.edu (Idaho State University) “Food Irradiation: Ten Most Commonly Asked Questions About Food Irradiation”


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