For related articles and more information, please visit OCA’s Genetic Engineering page and our All About Organics page.

When a team of activists wearing white hazmat suits showed up at a Chicago grocery store to protest the sale of genetically modified foods, they picked an unlikely target: Whole Foods Market.

Organic foods, by definition, can’t knowingly contain genetically modified organisms, known as GMOs. But genetically modified corn, soy and other crops have become such common ingredients in processed foods that even one of the nation’s top organic food retailers says it hasn’t been able to avoid stocking some products that contain them.

“No one would guess that there are genetically engineered foods right here in Whole Foods,” said Alexis Baden-Mayer, political director of the Organic Consumers Association, which organized the protest. The activists dramatically trashed a battery of well-known health food brands outside the store, including Tofutti, Kashi and Boca Burgers.

Though people have been modifying foodstuffs through selective breeding and other methods for centuries, genetically modified crops differ in that the plants grow from seeds in which DNA splicing has been used to place genes from another source into a plant. In this way, the crop can be made to withstand a weed-killing pesticide, for example, or incorporate a bacterial toxin that can repel pests.