Acute Consumption of Flavanol-Rich Cocoa and the Reversal of Endothelial Dysfunction in Smokers

Abstract

The circulating pool of bioactive NO and endothelium-dependent vasodilation is acutely increased in smokers following the oral ingestion of a flavanol-rich cocoa drink. The increase in circulating NO pool may contribute to beneficial vascular health effects of flavanol-rich food.

Effects of Flavonoid-Containing Beverages and EGCG on Endothelial Function

“…Other investigators have observed favorable vascular effects of black and green tea [58,59]. As outlined in the Table 1, improved endothelial function has also been demonstrated following consumption of other flavonoid-containing beverages and foods, including grape juice [49,60] wine, [61], dealcoholized red wine [62], cocoa [63][64][65], and chocolate [66].…”

(–)-Epicatechin mediates beneficial effects of flavanol-rich cocoa on vascular function in humans

“…In this context, FMD represents the current gold standard for the noninvasive measurement of endothelial function in humans. Regarding dietary interventions, various studies previously reported acute and chronic increases in endothelium-dependent vasodilation after the ingestion of flavanol-rich foods͞beverages such as red wine (32), purple grape juice (7), tea (33), cocoa (4,8), and chocolate (34). In most but not in all studies (4), endotheliumdependent vasodilation was measured as FMD by using methodologies comparable to those applied here.…”

“…Results that emanated from these studies corroborate the hypothesis that an increase in NO bioactivity represents the common underlying mechanistic principle for augmented vasodilation. Because of the fact that FMD is almost exclusively mediated by NO (35), increases in NOS activity are principally paralleled by increases in plasma nitroso species (36), and increased vasodilation can be reversed by using NOS inhibition (4,37). Thus, parallel measurements of FMD and circulating NO species, in conjunction with NOS inhibition studies, represent a mechanistically strong experimental framework.…”

“…Recent dietary interventions in humans using f lavanolcontaining foods have substantiated epidemiological data on an inverse relationship between flavanol intake and the risk of CVD, indicating various potential flavanol-mediated bioactivities, including the improvement of vasodilation (4)(5)(6)(7)(8), blood pressure (9), insulin resistance, and glucose tolerance (10), the attenuation of platelet reactivity (11), and the improvement of immune responses and antioxidant defense systems (12,13). Subsequent investigations in vitro were aimed at elucidating the molecular mechanisms that represent the causal mechanistic principles for flavanol-mediated bioactivities in vivo.…”

Cocoa, Blood Pressure, and Vascular Function

“…Flavanol intake improved FMD in hypertensive patients with normal (51) as well as IGT (54). Flavanol-rich cocoa beverage also acutely improved endothelium-dependent vasodilation, platelet function, and circulating bioactive NO in smokers (69,70). In 20 male smokers, dark chocolate, but not white chocolate, improved FMD after 2 h (7.0 vs. 4.4%, p = 0.026), and the effect lasted about 8 h after ingestion (70).…”