Rheumatoid arthritis and many other systemic rheumatic diseases remain illnesses of unknown cause for which current therapy is often inadequate. This leads patients to seek questionable remedies, prominent among which are dietary manipulations. Is there a role for dietary modifications in the routine therapy for patients with rheumatic diseases? This article discusses the relationships between diets, fasting, elemental nutrition, vitamins, minerals, and foods for rheumatic diseases. Known scientific-based evidence for the use, safety, and efficacy of diets and dietary-related practices subscribed by patients with rheumatic diseases are presented. Studies that link diet with arthritis offer the possibility of identifying new therapeutic approaches for selected patients and of developing new insights to disease pathogenesis. Dietary therapy for arthritis, however, is still being investigated.