The effect of acute consumption of a flavonol-rich cocoa drink on cerebral vasomotor reactivity in African Americans

African Americans (AA) are at great risk of cardiovascular diseases (CVD) which can lead to brain damage, dementia, and endothelial dysfunction. Decreased nitric oxide (NO) bioavailability contributes cardiovascular disease in AA population. Flavonols of the subclass known as flavonoids that have several beneficial effects on cerebral blood flow and cerebral vasomotor reactivity (CVMR). This study investigated the effects of the acute consumption of a flavanol-rich cocoa drink on CVMR. Ten non-smoking African American (6 males and 3 females) participants were randomly recruited. The subjects participated in two experimental sessions which were separated before and after the consumption of cocoa drink. For the pre-session, baseline CVMR was measured by the hypercapnia rebreathing (CVMR test) prior to the consumption of the cocoa drink and the again at 2h after consumption of one serving of the cocoa drink (45g of cocoa mixed with 8oz of cold water). Cerebral vascular conductance (CVC) was significantly increased in the post-study during hypercapnia rebreathing compared with the pre-study(post-study: 3.649 ± 1.833 CVC % of baseline/mmHg, pre-study: 2.483 ± 1.418 CVC % of baseline/mmHg vs. P < 0.05) Thus, CVMR was significantly increased in the post-study after the acute consumption of a flavonol-rich cocoa drink compared to the pre-study in AA.