Worst foods for arthritis. Wheat and gluten. These foods are a major driver of inflammation and arthritis. Allergy or intolerance to wheat and gluten is incredibly common and joint pain is one of the most common manifestations of the immune response to these foods.airy products. Milk and all foods that contain it are just as bad as gluten for many people with arthritis. The protein in milk is called casein, and it too irritates the gut lining and promotes leaky gut syndrome.