You must carefully check all labels. Prepared foods often have potato starch or tomato paste. Relish may contain peppers or paprika. Some people feel better when gluten is eliminated from their diet. Gluten is found in wheat, rye, barley, and oats.
Some people feel better when they give up all dairy products.
The problem may be molds. Foods like potatoes, sweet potatoes, nuts, berries, cantaloupe and honeydew melon get moldy easily. If you react to these foods sometimes, but not others, you may be allergic to certain molds rather than the foods. There are many other foods that can increase arthritis symptoms. Sometimes the only way to identify these foods is to either go on a fast with nothing but water for five days, or try a rare foods diet.