Irradiation and the fight against food bacteria

Shannon Lambie had never planted garlic before. So when she asked what she thought was a simple question, she got an answer that surprised her. As a volunteer with the Edible Garden Project in North Vancouver, Lambie was recently visiting Loutet Farm with local elementary school students. The group was learning about garlic: its lifecycle, how to cook it, and how it grows. After learning how garlic can grow from garlic bulbs planted in soil, Lambie asked one of the Loutet farmers if any garlic clove from store-bought garlic would work for planting. The answer was no.

She was told most of the non-organic garlic bulbs sold in stores have been irradiated and so do not sprout.

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"I was genuinely surprised and concerned that I didn't know this about our food," says Lambie, who is completing her master's degree in International Studies at SFU and is focused on community food production, particularly urban agriculture.

After some online research, she posted a blog on the Edible Garden Project website noting some of her concerns about irradiated food, including that the process contributes to the industrialization of the food system; reduces nutrient content; creates radiolytic products with unknown long-term effects; and it is not 100 per cent effective.

"I just thought maybe other people might want to know too," she says of posting the blog.

Health Canada notes on its website that food irradiation is a method of preserving food by exposing it to radiation energy to kill harmful bacteria. It is used to prevent foodborne illness and spoilage and to increase shelf life. Health Canada says food irradiation is safe for consumers.

Lambie says she does believe Health Canada's claim that food irradiation is probably not very dangerous, but "it might be," she says, noting the effects are not 100per-cent known.

Kevin Allen is an assistant professor of food microbiology in the Food, Nutrition and Health program at UBC. He specializes in foodborne pathogens and their effects on Canada's food chain. Allen says irradiation was developed more than 100 years ago and extensive research has shown it to be safe.

While it does reduce the nutrients in some foods, the reduction is not significant and is less than traditional thermal methods, he notes.

"When it's done properly and when food has been exposed to appropriate irradiation levels there's absolutely no risk to consumers, and, in fact, the food that results is microbiologically more stable and microbiologically safe," he says. "The biggest issue with irradiation is not that the food isn't safe because that's absolutely not the case. The biggest issue is that consumers aren't willing to accept it. They're worried that their food is going to glow, that it's going to be radioactive, and that it's going to cause them harm."

Irradiated food is exposed to certain doses of the energy source. The length of the irradiation affects the dose and the number of microorganisms destroyed.

"There is a flip side to that: if food is over-irradiated you can generate what are called radiolytic products and it can represent a risk to the public, but in facilities that do this they certainly use a controlled process that prevents that from happening," says Allen.

In Canada, irradiation is used on some produce, including some potatoes (to prevent them from sprouting). A lot of other countries use irradiation for insect control on many exported foods. Canada imports a lot of spices from Asia that are irradiated.

"There is a labeling requirement for foods that are irradiated," explains Allen. If 10 per cent of the product has been irradiated then the label has to have a Radura symbol on it, but spices are not identified as irradiated mainly because they are a small constituent of what is used in the cooking process so are not over that 10-percent bar.

Canada is connected to the globalized food supply and that has been a source of foodborne disease. However, it's not just the importation of food that is responsible for foodborne disease, notes Allen.

The recent recall of beef from the Alberta-based XL Foods plant due to E. coli contamination is a good example, he notes.

Canada does not use irradiation on meat, but Allen says irradiation would have made that beef safer before it was sold.

"We simply don't use it for meat because consumers aren't willing to accept the technology," he says. "And it's really too bad because irradiation is a really attractive intervention from a food-safety perspective."

Allen says it has been estimated that if Canada were to irradiate its food supply it would reduce foodborne disease by up to 25-50 per cent.

Consumers play an active role in food safety as well, especially in how they handle food.

"They have to do what they can in their home just in case we have failures upstream," says Allen. "We have to do what we can to protect ourselves. And what we really hope is that the people supplying us with food have done their job and that the government regulations are appropriate and will help contribute to a safe food supply."

Lambie agrees there are things consumers can do.

Being engaged with your community and talking with local farmers are ways people can become more connected and get more information about food issues, says Lambie.

"I think it's kind of sad when people don't know how the food they're eating got to them, where it came from and what it went through to get to them. Food irradiation is just one of those issues and there's a lot more," she says. "I think it would be really great if everyone could be mindful of the whole process."

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