Does Mediterranean Diet Reduce Cardiovascular Events and Oxidative Stress in Atrial Fibrillation?

Atrial fibrillation (AF) is characterized by enhanced oxidative stress and is complicated by cardiovascular events (CVEs), which are only partially prevented by anticoagulant treatment. The Mediterranean diet (Med-Diet) has a positive effect on atherosclerotic progression. In a prospective cohort of 709 anticoagulated AF patients, adherence to Med-Diet was assessed to investigate whether Med-Diet may reduce CVEs by lowering oxidative stress. The cohort was divided into three groups according to the Med-Diet score: low (0-3 points), medium (4-6 points), and high (7-9 points) adherence. During a mean follow-up of 39.9 months (2604.8 patients/year), we registered 72 (2.8%/year) CVEs: 23.4% in the low-adherence group, 8.4% in the intermediate-adherence group, and 5.3% in the high-adherence group (p<0.001). There were no differences in time in the therapeutic range among groups. The Med-Diet score was inversely correlated with sNOX2-dp (soluble NOX2-derived peptide; Rs: -0.297, p<0.001) and F2-isoprostanes (F2-IsoP; Rs: -0.411, p<0.001). Median values of sNOX2-dp (p<0.001) and F2-IsoP progressively decreased across groups (p<0.001). A Cox regression analysis showed that the Med-Diet score (HR: 0.771, p=0.001), F2-IsoP (HR: 1.002, p=0.004), and heart failure (HR: 1.876, p=0.024) predicted CVEs. In conclusion, these findings raise the hypothesis that adherence to Med-Diet could be associated with a reduction of CVEs, through an antioxidant effect, as shown by a concomitant downregulation of Nox2 and decreased excretion of F2-IsoP.