Effect of Mediterranean vs Paleolithic Diet on RA Activity, Sarcopenia and QOL: 12-Week RCT

Rheumatoid arthritis (RA) is a chronic systemic autoimmune disease characterized by progressive erosive polyarthritis, impaired physical function, and reduced quality of life. Patients with RA are at increased risk of comorbidities such as cardiovascular disease, osteoporosis, infections, and mortality due to ongoing inflammation and long-term immunosuppressive therapy. Diet and nutrition have gained attention as potential modulators of RA activity, partly due to their effects on systemic inflammation, gut microbiota, and antioxidant status. The Mediterranean diet (MD), rich in fruits, vegetables, olive oil, and limited meat, has shown beneficial effects on cardiovascular health, RA symptoms, and quality of life, although evidence is still of moderate certainty. The Paleolithic diet (PD), emphasizing lean meats, fish, fruits, vegetables, nuts, and seeds while excluding grains, dairy, and processed foods, has shown promising anti-inflammatory effects in autoimmune conditions, metabolic improvements, and reduction of RA-related symptoms in preliminary studies. This randomized controlled trial will recruit adults aged 40-60 years with RA from the Kasr Al-Ainy Internal Medicine Inpatient and Outpatient Rheumatology Clinics. Participants will be randomly assigned to one of three groups: Mediterranean diet, Paleolithic diet, or control (usual diet) for 12 weeks. Baseline and post-intervention assessments will include: Nutritional assessment via Food Frequency Questionnaire and Nutrition Awareness Questionnaire Anthropometric measurements: weight, height, BMI, waist, and hip circumference RA disease activity using DAS28 Laboratory investigations: CBC, CRP, ESR, lipid profile, fasting glucose, HbA1c Patient-reported outcomes: fatigue, sleep quality, stress, and quality of life The primary objective is to evaluate whether dietary interventions improve nutritional status and RA disease activity. Secondary objectives include comparing the effects of MD and PD on fatigue, sleep, stress, and overall quality of life. The study seeks to provide evidence for dietary strategies as adjunctive management for RA, improving both clinical and metabolic outcomes.