Irradiated food: Zap with caution.

Image by Nicolas Raymond |

Image by Nicolas Raymond |

Irradiated foods are a virtually unavoidable kind of processed food item filling grocery stores and markets all over the country.  If you have already had at least one meal today, you most likely have consumed something irradiated. Irradiated food works by applying ionizing radiation to food in order to kill microorganisms and other unwanted bacteria, though the introduction of irradiated food was also largely a result of the demand to extend the shelf life of food products.  Although the irradiation of food has proven beneficial in some ways, it has also been associated with the causation of diseases such as cancer.  In addition, it also lowers the nutrient content of some foods.

The idea of using irradiation in preserving food started with the discovery of radioactivity in 1895 when Henri Becquerel found out that natural uranium had the capability of affecting photographic plates that were covered by lightproof paper. Food is passed through an irradiator, where it is exposed to an ionizing energy source. Following Becquerel’s discovery, research on food irradiation in the United States started in the early 1900s, primarily to kill potentially harmful bacteria present in food.  Food irradiation is still used today to eliminate food-borne pathogens like salmonella.           

Labeling of the irradiated foods is aimed at informing the consumer of the use of radiation in preserving the food they plan to consume. The irradiated labels have the words “Treated with Radiation” together with the irradiation logo, known as the Radura (as shown in the photo above). The labeling of the irradiated foods started in the United States in 1958. The regulations by Health Canada specify which types of foods may be irradiated, as well as the treatment levels permitted. Foods that may be irradiated in Canada include potatoes, onions, wheat, flour, and whole or ground spices. The labeling regulation in Canada also calls for identification of the irradiated foods by use of labels on the packed products in addition to labeling signs that clearly reveal that food in the package has been irradiated. Other countries that label irradiated foods include New Zealand and Australia.

Some of the things that determine the dose of irradiation required include the duration of exposure to radiation energy, food density, as well as the amount of energy produced by the irradiator. For instance, low doses (0.3 kiloGray, or kGy) of Cobalt-60 is effective against the trichina parasite in fresh pork.  Food irradiation is associated with the creation of new chemicals in foods, referred to as radiolytic products. Some of these radiolytic products (such as benzene in irradiated beef) are potentially linked to cancer in humans. Irradiation also causes unpleasant changes to food; for instance, it can destroy essential nutrients such as vitamins. One serious case associated with irradiated food production is that of Kiwi, a company involved in the selling of tomatoes in Australia. A great percentage of tomatoes sold in New Zealand are made up of the unlabeled irradiated tomatoes from Australia.

About 57% of consumers in Canada are not familiar with the process of food irradiation, though many, once aware, are open to food treated with low doses of radiation in order to prevent foodborne illnesses.  Some, however, believe that irradiated foods pose a health hazard.  Irradiation of food has many benefits such as improving microbiological value and extending the shelf life of food. However, the negative effects of irradiated foods must also be considered; the rays emitted during the eradiation process may be linked to cancer, one of today’s biggest health concerns. Due to the negative effects associated with the irradiated foods, it is advisable for organizations and governments to inform the public openly about the potential negative impacts of consuming irradiated foods.