Acute Natural Cocoa Consumption Improves Cerebral Vasodilatory Capacity in College‐Aged African Americans

Abstract

African Americans (AA) have increased risk for cerebral vascular disease including stroke and Alzheimer's disease relative to Caucasian Americans (CA). We recently reported that relatively young AA have attenuated cerebral vasodilatory response during rebreathing‐induced hypercapnia relative to CA. This study tested the hypothesis that acute natural cocoa (NC) consumption (13g NC) restores this response in AA. 14 college‐aged AA and 14 age / sex / body mass matched CA underwent a rebreathing protocol while cerebral blood velocity (CBFV) was measured before and 2 hr post consumption of a NC‐containing drink or an isocaloric NC‐free placebo (randomized order, single‐blinded). Cerebral vascular conductance (CVCI) was calculated as CBFV / MAP. The response to rebreathing was expressed as % of baseline CVCI (% CVCI). Following NC consumption the total range of increase and the maximal increase in %CVCI during hypercapnia was increased in the AA (P<0.01 for both variables) whereas there was no effect of NC consumption in the CA (P>0.05 for both variables). Following NC consumption the cerebral vascular responses were similar between AA and CA (P>0.05 for all variables). Consumption of the placebo beverage had no effect on cerebral vascular function in either cohort (P>0.05 for all variables). These data support the hypothesis that NC consumption can acutely augment cerebral vasodilatory capacity in AA.This study was supported by institutional start‐up funds awarded to R. Matthew Brothers. The beverages were generously provided by the Hershey Company; Hershey, Pennsylvania.