That's a million-dollar question. Despite years of study, no conclusive evidence exists to show that particular foods make rheumatoid arthritis symptoms flare up or decrease. Some research has shown a link between eating certain fish oils and reducing joint inflammation in people with rheumatoid arthritis, but more research is needed to assess this possible benefit.
It's smart to consider how your lifestyle might play a role in the ups and downs of rheumatoid arthritis. Being too heavy, for example, stresses your weight-bearing joints, increasing joint pain, stiffness and inflammation.
You can also stay away from any food that seems to make your symptoms worse. But don't exclude whole food groups or large numbers of foods without consulting a registered dietitian or your doctor.