Diet intervention improves cardiovascular profile in patients with rheumatoid arthritis: results from the randomized controlled cross-over trial ADIRA

BACKGROUND: The chronic inflammation in patients with rheumatoid arthritis (RA) increases the risk for cardiovascular diseases (CVD). The contribution of diet as a risk factor for CVD among these patients is however not fully understood. The aim of this study is to investigate if a proposed anti-inflammatory diet improves cardiovascular profile in weight stable patients with RA. METHODS: Patients (n = 50) with RA were included in a cross-over trial. They were randomized to either a diet rich in whole grain, fatty fish, nuts, vegetables and fruit and supplemented with probiotics, or a control diet resembling average nutritional intake in Sweden, for ten weeks. After a 4-month washout they switched diet. Participants received food bags and dietary guidelines. Primary outcome was triglyceride (TG) concentration. Secondary outcomes were total-, high density lipoprotein- (HDL) and low density lipoprotein- (LDL) cholesterol, Apolipoprotein-B100 and -A1, lipoprotein composition, plasma phospholipid fatty acids and blood pressure. RESULTS: Forty-seven patients completed at least one period and they remained weight stable. There was a significant between-dietary treatment effect in TG and HDL-cholesterol concentration in favor of intervention (p = 0.007 and p = 0.049, respectively). Likewise, Apolipoprotein-B100/A1 ratio shifted toward a less atherogenic profile in favor of the intervention (p = 0.007). Plasma fatty acids increased in polyunsaturated- and decreased in monounsaturated- and saturated fatty acids between diet periods in favor of the intervention period. CONCLUSION: Blood lipid profile improved indicating cardioprotective effects from an anti-inflammatory dietary intervention in patients with RA. TRIAL REGISTRATION: This trial is registered at ClinicalTrials.gov as NCT02941055. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s12937-021-00663-y.