1Escola Superior de Tecnologia da Saúde de Coimbra, Fisiologia Clínica - Coimbra - Portugal
2Instituto de Investigação e Formação Cardiovascular - Coimbra - Portugal
Introduction: The aim of this study was to assess the vascular benefits of a dark chocolate intake program, particularly over the endothelial function and the central arterial hemodynamics, in healthy and young individuals.
Methods: A randomized and controlled trial was carried out involving 60 healthy young individuals, randomized into two groups: control group (CG; n=30) and intervention group (IG; n=30). The IG ingested a daily dosage of 10g of dark chocolate (>75% cocoa) for a month. All the individuals were submitted to two clinical evaluations, basal and after one month of intervention, in which their weight, height, body mass index (BMI), systolic blood pressure (SBP), diastolic blood pressure (DBP), heart rate (HR), flow-mediated dilation (FMD), arterial stiffness index (ASI), aortic pulse wave velocity (PWV) and pulse wave analysis over the carotid artery (PWA) were assessed.
Results: CG and IG groups had similar baseline clinical and demographic characteristics. After the intervention, BMI, HR and brachial BP didn’t suffer significant variations in either group. The baseline PWV and PWA parameters were similar in both groups, but were significantly different in the second evaluation, with the IG showing lower PWV, lower ASI and lower augmentation indexes (AiX). Arterial function improved after intervention in the IG, with PWV decreasing from 6.13±0.41m/s (baseline) to 5.83±0.53 m/s (post-intervention; p=0.02), with no significant differences observed in the CG. A significant decrease in ASI (0.16±0.01 at baseline and 0.13±0.01 post-intervention; p<0.001) and AiX (at baseline -8.88±20.75 and post-intervention -16.57±16.16; p=0.07) were also depicted for the IG, but not for the CG. The basal FMD was similar in the IG and the CG, but was significantly different in the second evaluation, with the IG showing higher FMD values (23±7% versus 13±6%, respectively for the IG and the CG; p<0.001). Endothelial function improved in the IG after the 1 month intervention, with the FMD increasing from 14±5 % (baseline) to 23±7 % (post-intervention; p<0.001), with no significant differences in the CG.
Conclusion: The daily ingestion of 10g dark chocolate (>75% cocoa) during a month improves the vascular function in young and healthy individuals, probably reflecting a positive modulation of the endothelium-dependent vasodilation.