All fruits and vegetables are gluten-free unless processed or mixed with anything that contains gluten. The gluten protein comes from wheat, barley and rye and can be used as an additive or a preservative in processed foods.
Gluten irritates the small intestines of people who have celiac disease which, if not treated, can lead to cancer of the small intestine. Because following prescribed treatment is so important, the Mayo Clinic Gluten-Free Diet lists gluten-free foods, including fruits, vegetables, fresh eggs, beans, seeds, nuts, fresh meats, fish, poultry and rice. The key to eating a gluten-free diet is to learn how to recognize which foods to avoid, look for labels that say "gluten-free," and strictly follow the doctor's prescribed treatment.