Polytechnic Institute of Coimbra, Coimbra Health School, LabinSaude, Portugal.
University of Gothenburgh, Salgrenska Academy, Sweden.
Nutrition. 2019 Jul-Aug;63-64:175-183. doi: 10.1016/j.nut.2019.02.017. Epub 2019 Feb 27.
The aim of this study was to evaluate and explore the benefits of long-term dark chocolate intake in young, healthy adults by measuring cardiovascular function.
A randomized study was conducted with 30 healthy participants ages 18 to 27 y. Half of the participants ingested a 20-g dose of lower cocoa chocolate (LCC; ∼55%; 12.6 ± 1.4 mg equivalent of epicatechin/g) and the others ingested a daily dose of 20 g of higher cocoa chocolate (HCC; ∼90%; 18.2 ± 2.6 mg equivalent of epicatechin/g). A baseline evaluation was performed before the participants started ingesting the assigned chocolate for a 30-d period, after which a final evaluation was performed. Each evaluation included heart ultrasonography, carotid-femoral pulse wave velocity (PWV) and carotid pulse wave analysis, flow-mediated slowing (FMS), and an analysis of the ventricular-arterial coupling (VAC), which reflects the matching between the aorta and the left ventricle (ratio of arterial elastance to left ventricle elastance).
The baseline evaluation presented similar values within normal range in both groups. The positive vascular effects were overall more distinct in the group eating the HCC. No structural modifications on the heart were found after the intervention, notwithstanding cardiac function was improved on certain functional parameters in the HCC group only. A statistically significant improvement was depicted over the brachial and central systolic and pulse pressures in the HCC group, and a trend for improvement in the reflected waves component (Aix) and the FMS was also observed in the HCC, but not in the LCC group. VAC parameters were similar at baseline between groups, but showed a significant improvement in the HCC group after intervention, increasing from 0.674 to 0.719 (P = 0.004), so that the post-intervention VAC was significantly higher in the HCC group than in the LCC group (P < 0.05). In addition, significant variation was observed in both groups regarding arterial and left ventricle elastances, stroke work, and potential energy, with greater mean differences identified in the HCC group.
This study demonstrated that regular consumption of HCC has beneficial effects on the cardiovascular system in young, healthy adults, improving vascular function by reducing central brachial artery pressures and promoting vascular relaxation, and thus enhancing the matching of the arterial system with the left ventricle.
本研究旨在通过测量心血管功能来评估和探讨长期食用黑巧克力对年轻健康成年人的益处。
这是一项随机研究，共有 30 名年龄在 18 至 27 岁的健康参与者参与。一半的参与者摄入 20 克低可可巧克力（LCC；约 55%；12.6±1.4 毫克表儿茶素/克），而其他人则每天摄入 20 克高可可巧克力（HCC；约 90%；18.2±2.6 毫克表儿茶素/克）。在参与者开始摄入指定巧克力的 30 天内进行基线评估，之后进行最终评估。每次评估均包括心脏超声、颈动脉-股动脉脉搏波速度（PWV）和颈动脉脉搏波分析、血流介导的弛豫（FMS）以及心室-动脉偶联（VAC）分析，VAC 反映主动脉与左心室的匹配情况（主动脉弹性与左心室弹性的比值）。
两组的基线评估值均在正常范围内，且相似。在摄入 HCC 的组中，整体的血管正向作用更为明显。尽管在 HCC 组中仅某些功能参数显示心脏功能有所改善，但干预后并未发现心脏结构发生变化。在 HCC 组中，肱动脉和中心收缩压和脉压均有显著改善，且 FMS 中反射波成分（Aix）也有改善趋势，但在 LCC 组中无此趋势。VAC 参数在两组间的基线相似，但在 HCC 组中干预后有显著改善，从 0.674 增加到 0.719（P=0.004），因此 HCC 组的干预后 VAC 显著高于 LCC 组（P<0.05）。此外，两组的动脉和左心室弹性、心搏功和势能均有显著变化，HCC 组的平均差异更大。
本研究表明，在年轻健康成年人中，经常食用 HCC 对心血管系统有益，可通过降低中心肱动脉压和促进血管舒张来改善血管功能，从而增强动脉系统与左心室的匹配。
