Dietary interventions for reduced disease activity in patients with rheumatoid arthritis: a critical review

Abstract

Rheumatoid arthritis (RA) is a chronic autoimmune condition in which an inflammatory response causes permanent damage to the cartilage and bone of affected joints, and is often associated with additional systemic complications. The pathogenesis of RA is not fully understood, and standard treatment requires trial and error of pharmacological interventions that may have serious side effects. Evidence suggests that dietary interventions, when added to standard pharmacotherapies, may effectively mitigate disease progression and symptoms of RA. The aim of the current review was to evaluate existing research on dietary interventions for treatment of RA symptoms to determine which diet therapies may be effective for improving symptoms and inflammatory markers of disease activity. Relevant studies were identified within PubMed, and inclusion and exclusion criteria were established a priori. Included studies incorporated an experimental design, a diet therapy component, and human participants with an existing diagnosis of RA. Studies not available in the English language or as full text, were excluded. The initial search yielded 110 records, and after evaluation of inclusion and exclusion criteria and topic relevance, results of nineteen studies were synthesized for interpretation. Included study interventions varied by duration, participants, objective, and prescribed diet. Assessments of disease activity were categorized as subjective, semi-objective, or objective markers of symptoms and inflammation. The prescribed diets included a period of fasting followed by a plant-based diet, vegan diets, Mediterranean diets, and three other dietary interventions that were hypothesized to have anti-inflammatory effects in patients with RA. A reduction in overall disease activity was observed in all nineteen of the included studies. However, statistical significance was more prevalent for semi-objective measurements of disease activity than more subjective and objective measures. Overall, the current review suggests that plant-based dietary interventions may be effective for reducing subjective measures of disease activity in patients with rheumatoid arthritis. Additional high-quality and longer-term interventions are needed to identify which dietary components and additional dietary interventions may be beneficial for reducing objective inflammatory markers of disease activity, when added to pharmacological therapy in patients with RA.