Clinical Study Central Arterial Hemodynamic Effects of Dark Chocolate Ingestion in Young Healthy People: A Randomized and Controlled Trial T. Pereira, 1 J. Maldonado, 2 M. Laranjeiro, 1 R. Coutinho, 1 E. Cardoso, 1 I. Andrade, 1 and J. Conde 1 1 Departamento de Cardiopneumologia, ESTESC, Instituto Polit´ ecnico de Coimbra, Rua 5 de Outubro, SM Bispo, Apartado 7006, 3046-854 Coimbra, Portugal 2 Instituto de Investigacao e Formacao Cardiovascular, Quinta da Portela, Rua Princesa Cindazunda, Lote 9.3, Loja 94, 3030-503 Coimbra, Portugal Correspondence should be addressed to T. Pereira; telmo@estescoimbra.pt Received 27 February 2014; Revised 7 May 2014; Accepted 8 May 2014; Published 27 May 2014 Academic Editor: Frans Leenen Copyright © 2014 T. Pereira et al. Tis is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Introduction. Te aim of this study was to assess the vascular benefts of dark chocolate in healthy and young individuals. Methods.A randomized and controlled trial was carried out involving 60 healthy volunteers, randomized into two groups: control group (CG;  = 30) and intervention group (IG;  = 30). Te IG ingested a daily dosage of 10 g of dark chocolate (>75% cocoa) for a month. Blood pressure (BP), fow-mediated dilation (FMD), arterial stifness index (ASI), aortic pulse wave velocity (PWV), and pulse wave analysis (PWA) were assessed at baseline and one week afer the one-month intervention period. Results. Arterial function improved afer intervention in the IG, with PWV decreasing from 6.13 ± 0.41 m/s to 5.83 ± 0.53 m/s ( = 0.02), with no signifcant diferences observed in the CG. A signifcant decrease in ASI (0.16 ± 0.01 to 0.13 ± 0.01;  < 0.001) and AiX (−15.88 ± 10.75 to −22.57 ± 11.16;  = 0.07) was also depicted for the IG. Endothelial function improved in the IG, with the FMD increasing 9.31% afer the 1-month intervention ( < 0.001), with no signifcant variation in the CG. Conclusion. Te daily ingestion of 10 g dark chocolate (>75% cocoa) during a month signifcantly improves vascular function in young and healthy individuals. 1. Introduction Cardiovascular diseases represent an important worldwide public health problem, being the main cause of mortality and morbidity [1]. Recent studies have shown that the severity of endothelial dysfunction relates to the risk for an initial or recurrent cardiovascular event [2]. Te endothelium acts to maintain vascular homeostasis through multiple complex interactions with cells in the vessel wall and lumen. Te endothelium regulates vascular tone (balancing the production of vasodilators and vasoconstric- tors), controls blood fuidity and coagulation (producing fac- tors that regulate platelet activity, the cloth cascade, and the fbrinolytic system), and produces cytokines and adhesion molecules (regulate the infammatory process) [2]. Tere are multiple risk factors, such as smoking, ageing, hypercholes- terolemia, hypertension, hyperglycemia, and a family history of premature atherosclerotic disease, all of them associated with a loss of endothelium-dependent vasodilation. Nutrition has long been thought to have a profound efect on endothelial function [3]. Indeed, epidemiologic evidence supports the idea that diets rich in fruits and vegetables promote health and attenuate the onset of various diseases, including cardiovascular disease [4]. In the context of cardiovascular disease, favan-3-ol (favanols) has received considerable attention. Cocoa and chocolate products have a much higher favan-3-ol con- centration and total antioxidant capacity per weight than other favonoid-containing beverages such as red wine and green or black tea [4, 5]. Flavonoid-rich chocolate markedly Hindawi Publishing Corporation Cardiology Research and Practice Volume 2014, Article ID 945951, 7 pages http://dx.doi.org/10.1155/2014/945951