Elimination reintroduction diets and oral food challenge in adults with rheumatoid arthritis: a scoping review.

Many people with rheumatoid arthritis (RA) believe that certain foods may influence disease activity. Elimination reintroduction diets and oral food challenges are dietary strategies used to identify foods that may exacerbate symptoms. This review summarises and appraises the literature on elimination diet interventions that include food reintroductions or oral food challenges in adults with RA. It describes study design, measures used to assess the effects of food exclusion and challenge, foods identified that may affect RA symptoms, and the measures used to assess the outcome of excluding those foods. A search of five databases, two thesis repositories and Open Grey was conducted to identify records published from inception to January 2025, using terms related to RA, elimination diets and food sensitivity. Eligible records were screened independently by two reviewers, and data extraction followed Joanna Briggs Institute guidelines. Data are presented using a narrative synthesis approach with descriptive data analysis. In total, forty-eight records met inclusion criteria comprising twenty intervention studies (sample sizes 4-94) and seventeen case studies, conducted across twelve countries (1949-2024). Interventions included single-food exclusions, few-food diets, low-allergen meal replacements and fasting protocols. Reintroduction methods varied from a single-food challenge to multiple reintroductions, with five studies using blinded challenges. Outcome measures included physician- or participant-observed symptom changes, clinical assessments and laboratory measures, though these were heterogeneous. Findings reveal a lack of standardised protocols, dated methodologies and limited contemporary research. Controlled studies are needed to establish evidence-based protocols, investigate mechanisms, and guide dietary strategies as adjuncts to RA pharmacological treatment.