The Effect of Dark Chocolate Consumption on Arterial Function in Endurance Male Runners: Prospective Cohort Study

Foods rich in polyphenols have beneficial effects on health. This study aimed to examine the impact of dark chocolate on endurance runners' arterial function. Forty-six male amateur runners, aged 25-55, participated. The initial assessments included clinical testing, arterial stiffness measurements, and a cardiopulmonary exercise test. The participants then consumed 50 g of dark chocolate (70% cocoa) daily for two weeks, maintaining their usual training routine. After this period, the baseline assessment was repeated. The results showed significant improvements. Pulse wave velocity decreased by 11.82% (<i>p</i> < 0.001), and augmentation index by 19.47% (<i>p</i> < 0.001). Systolic brachial blood pressure reduced by 2.12% (<i>p</i> < 0.05), diastolic by 2.79% (<i>p</i> < 0.05), and mean pressure by 2.41% (<i>p</i> < 0.05). Central arterial pressure also decreased, with systolic by 1.24% (<i>p</i> < 0.05), diastolic by 2.80% (<i>p</i> < 0.05), and mean pressure by 2.43% (<i>p</i> < 0.05). Resting heart rate increased by 4.57% (<i>p</i> < 0.05) and left ventricular ejection time decreased by 4.89% (<i>p</i> < 0.05), particularly in athletes over 40. Exercise time increased by 2.16% (<i>p</i> < 0.05), heart rate (max) by 1.15% (<i>p</i> < 0.05), VO₂max by 2.31% (<i>p</i> < 0.05), and anaerobic threshold shifted by 6.91% (<i>p</i> < 0.001) in exercise time and 6.93% (<i>p</i> < 0.001) in VO₂max. In conclusion, dark chocolate improves arterial function in endurance runners, enhancing vascular health.