A: When a person is lactose intolerant, it means they don't have enough of the digestive enzyme lactase. Lactase is the enzyme that breaks down lactose, the type of sugar that's found in dairy products. Since there isn't enough lactase, the additional lactose accumulates in the colon.

A: Irradiation is a process that involves treating food with radiation to help kill bacteria and parasites that might otherwise cause foodborne illnesses.