Rheumatoid arthritis (RA) is a chronic inflammatory disease that affects 0.5-1% of the population, and where many patients in spite of modern pharmacological treatment fail to reach remission. The main goal of the randomized cross-over trial ADIRA (Anti-inflammatory Diet In Rheumatoid Arthritis) is to test the hypothesis that a diet intervention will decrease disease activity and improve quality of life in patients with established RA.

Rheumatoid arthritis (RA) is a chronic inflammatory disease that affects 0.5-1% of the population, and where many patients in spite of modern pharmacological treatment fail to reach remission. This affects physical as well as mental wellbeing and leads to severely reduced quality of life and reduced work capacity, thus yielding high individual as well as societal costs. To optimize treatment, alternatives such as diet should be evaluated as complement to pharmacological treatment. The main goal of the randomized cross-over trial ADIRA (Anti-inflammatory Diet In Rheumatoid Arthritis) is to test the hypothesis that a diet intervention will decrease disease activity and costs and improve quality of life in patients with established RA. In total, 60 RA patients with moderate disease activity will be randomized to receive initially either a portfolio diet based on several food items with suggested anti-inflammatory effects or a control diet (western type), during 2 x 10 wks with a 3 months wash-out between diets. Both groups continue with regular pharmacological treatment. Known food biomarkers will be analyzed to measure intervention compliance. Impact on disease activity (measured by DAS28, a composite score which predicts disability and progression of RA) and quality of life is evaluated after each diet regimen. Metabolomics will be used to evaluate the potential to predict responders to dietary treatment. ADIRA will provide evidence whether dietary treatment of RA leads to more patients reaching remission and improved quality of life and work capacity as well as reduce individual and societal costs. Scientific evidence exists for anti-inflammatory effect by single foods on RA, but no study exists where these foods have been combined to obtain maximum effect and thus have the potential to offer a substantial improvement in patient life quality. Such evidence has been asked for by RA patents as well as by treating physicians.

Inclusion Criteria:

• Subjects with established RA, disease duration >2 years, disease activity DAS28 >= 2.6 and a disease that is clinically stable and under adequate control and medication, will be invited to participate.

Exclusion Criteria:

• Other life threatening diseases, pregnancy, lactation, food intolerance or allergy to food included in the trial, ability to understand information in Swedish

Not approved by the Ethical Review board