Background: Rheumatoid arthritis (RA) is a chronic, autoimmune disease that is associated with local and systemic inflammation, resulting in chronic pain and physical function limitations that may negatively impact quality of life (QOL). Despite advances in pharmacological therapies, currently available treatment options may be associated with adverse events and come at a high price tag. As a result, research efforts have grown to focus on nutritional interventions to support pharmacological therapies, reduce inflammation (targeting biomarkers of disease activity) and improve QOL.

Objectives: In this systematic review, data was collected on the most recent non-pharmacological interventions used in RA treatment. The efficacy and potential practical applications of various nutritional interventions used in the RA management will be discussed. This review has been divided into three parts. In this first section, we discuss five structured diets and their clinical impacts on patients with RA. The diets discussed in this article include the anti-inflammatory diet in RA (ADIRA) diet, elemental and elimination diets, weight loss, and a Mediterranean diet (MD). For more information on the other contents of this systematic review you may refer to Part 2: Supplementation and Part 3: Fruit and herbs.

Methods: A search of the literature was conducted to identify nutritional interventions in the progression and management of RA. Eligible study designs included meta-analyses, systematic reviews, randomized control trials (RCT) and prospective/retrospective studies. Exclusion criteria included non, in vivo human studies, n<40, cross-sectional studies, case-studies, and lack of access to available text.

Results: Initially, 334 articles were identified. After removing studies for lack of relevance, exclusion criteria, and duplicates, 22 articles remained. The eligible articles were divided into five groups based on design: meta analyses, systematic reviews, RCTs, literature reviews, and prospective studies. The eligible articles were grouped together based on intervention type: diets, supplementation and the implementation of fruits and herbs. Five articles were placed under the category of diet which includes one systematic review, two RCT and two literature reviews.

Conclusion: Dietary interventions may be an effective method for reducing inflammation and symptoms associated with RA. Significant improvements in indices of RA, such as the DAS-28 and HAQ, were observed with the use of a MD, vegan, and vegetarian diets as well as exercise and weight loss. These outcomes were supported by previous reviews demonstrating the safety and efficacy of these adjuvant therapies. This review also determined that the Anti-inflammatory Diet in RA (ADIRA) diet, as well as elimination and elemental diets all require further research before recommendations can be made on these interventions. However, past research has identified highly immunogenic foods which may induce symptoms and therefore clinicians should familiarize themselves with these triggers to educate their patients.

Arthritis, Diet, Nutrition, Review, Rheumatoid arthritis