Researchers say irradiation of food could reduce foodborne illness outbreaks

Research funded in part by the CDC has shown that food irradiation could reduce the number of foodborne outbreaks caused by pathogens.

For the project, researchers looked at 2,153 foodborne outbreaks from 2009 to 2020 caused by Campylobacter, Salmonella, E. coli, or Listeria monocytogenes. Of those, 482 included information regarding processing methods other than unknown or missing values. None of those had irradiation listed as a processing method.

A variety of foods sold in the United States are eligible for irradiation. Those foods include meat, poultry, fresh shell eggs, spices, some fruit, and fresh produce. Of the 482 outbreaks, 155 were linked to irradiation-eligible food, none of which were irradiated.

“Food irradiation has been studied globally for decades and is a safe, effective means of reducing foodborne illness-causing pathogens, sterilizing insects, delaying ripening or sprouting, and extending shelf life,” according to the researchers. 

“The U.S. Food and Drug Administration has approved various foods for irradiation, including meat, poultry, fresh shell eggs, and spices. However, irradiation has not been widely adopted in the United States because of high fixed costs and the perception of consumer unwillingness to purchase irradiated food. Estimates of the amount of irradiated food available in the United States are scarce. Still, as of 2010, approximately one-third of spices consumed and  less than 0.1 percent of imported fruit, vegetables, and meats were irradiated.”

Of the 482 outbreaks known to have not had irradiation as part of processing, 155 were linked to a food eligible for irradiation. Those outbreaks resulted in 3,512 illnesses, 463 hospitalizations, and 10 deaths. The most common sources were chicken with 52 outbreaks, beef with 31, and eggs with 29, comprising 72 percent of outbreaks linked to irradiation-eligible foods, according to researchers.

“These results suggest that irradiation could prevent or mitigate some outbreaks. Prioritizing food irradiation efforts, particularly for chicken, beef, and eggs, could substantially reduce outbreaks and illnesses,” researchers concluded.

“The illnesses, hospitalizations, and deaths associated with outbreaks linked to irradiation-eligible foods might have been prevented or reduced had these foods been irradiated. Irradiation has repeatedly been proposed as a strategy to reduce foodborne disease outbreaks. Irradiation typically eliminates a large proportion of pathogenic microorganisms.”

Food irradiation does not use radiation perceived as radioactive and does not leave food with a radioactive charge. If used at sufficient doses, it can neutralize Campylobacter, Salmonella, E.coli, and Listeria monocytogenes, the leading pathogens behind foodborne illnesses in the United States.

“Irradiation typically eliminates a large proportion of pathogenic microorganisms. The efficacy of irradiation depends on factors like temperature and water content. Food may become contaminated after irradiation. Irradiation can improve food safety, complementing existing food safety practices. Consumer demand for irradiated foods may be increased through education,” according to the researchers.

Dr. Marta Zlotnick, the lead researcher on the project, is an Oak Ridge Institute for Science and Education Fellow at the Centers for Disease Control and Prevention in Atlanta, GA. Her work focuses on preventing zoonotic diseases originating from food or animal contact.

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