The Effects of Dark Chocolate Implementation in the Reduction of Oxidative Stress and Improvement of Vascular Function and Physical Performance in Elite Athletes

Dark chocolate (DC) is rich in epicatechin which augments nitric oxide (NO) production through endothelium-dependent influences. The increased bioavailability and activity of NO have been demonstrated to statistically increase flow-mediated dilation in healthy subjects and in hypertensive patients. DC supplementation has been hailed for its positive effects on cardiovascular health and it has been proposed as a booster of physical performance in athletes, however the mechanisms by which DC improves oxidative stress, vascular function and athletic performance are not fully understood. The investigators designed a human study assessing how DC improves NO bioavailability and activity in elite athletes. Twenty-four elite soccer players (aged 18-35 years old, all males) are divided in 2 groups and randomly assigned to receive DC (85% cocoa), 40g per day or white/milk chocolate (<35% cocoa) for 30 days. The primary outcome measure is the evaluation of Soluble NOX2-derived peptide (sNOX2-dp), a direct marker of NADPH oxidase activation. The secondary outcome measures are other markers of oxidative stress, as the soluble P-selectin (sPs), Vitamin E, soluble CD40 Ligand (sCD40L), a marker of in vivo platelet activation and flow-mediated dilation assessed by vascular ultrasound. All parameters are assessed at baseline and after 30 days in both groups.