Cocoa flavanols: effects on vascular nitric oxide and blood pressure

Abstract

Diets rich in fruits and vegetables have been associated with benefits for human health. Those effects have been partially ascribed to their content in flavonoids, compounds that are present in many edible plants and its derived foods. In humans, a significant number of studies has been developed analyzing the effect of foods and beverages rich in flavonoids on the presence and progression of risk factors associated to cardiovascular diseases, including hypertension. Cocoa derived products, rich in flavanols, have been thoroughly studied and demonstrated to be efficient improving endothelial function and decreasing blood pressure in humans and animals. However, the final chemical species and the mechanism/s responsible for these effects have not been completely defined. In this paper we present data supporting the hypothesis that flavanols could define superoxide anion production and then, establish optimal nitric oxide levels and blood pressure.

Diagnosed, undiagnosed and overall atrial fibrillation research on population over 60 year-old. AFABE study

“…This improvement reflects an optimization of the endothelium function, fact already demonstrated in similar studies. For example, Engler et al, [18,19] indicate that dark chocolate improves endothelium-dependent vasodilatation, what upholds the observation, during the study, of the improvement of the endothelial function after two weeks of intervention with chocolate rich in cocoa, even though no difference in arterial pressure was found. In a recent meta-analysis, Ried et al, [20], documented theinexistence of alterations on the tensional profile in normotensive individuals, after the ingestion of products rich in cocoa, fact that is along the line with the results obtained in the present study, during which no differences between SBP and DBP were observed in the CG versus IG at both moments of assessment.…”

“…Therefore, the naturally optimized vasomotricity in these individuals should make the endothelium more reactive to the vasomotor compounds in dark chocolate. On the other hand, and in opposition to other studies [19,21], dark chocolate was used because it's formulated with a higher percentage of cocoa bean liquor, therefore contains greater amounts of flavonoids as compared with other alternatives [25].…”

“…In a recent meta-analysis, Ried et al, [20], documented theinexistence of alterations on the tensional profile in normotensive individuals, after the ingestion of products rich in cocoa, fact that is along the line with the results obtained in the present study, during which no differences between SBP and DBP were observed in the CG versus IG at both moments of assessment. The oral ingestion of a cocoa drink resulted in an increase in the concentration of nitric oxide (NO) derived species in plasma and urine of healthy individuals that were associated with the improvement of FMD [19,21]. Grassi et al, [22,23] verified that after consuming 100g of chocolate during 2 weeks, FMD improved in hypertensive individuals (with or without impaired glucose tolerance), thus concluding that by balancing the total ingestion of calories, the natural active compounds from cocoa products can provide cardiovascular benefits if included as part of a healthy diet for hypertensive patients.…”

Cocoa, Blood Pressure, and Vascular Function

“…In particular, dark chocolate intake reduced mean SBP by 2.9 mmHg (p < 0.001) and DBP by 1.9 mmHg (p < 0.001); these results were accompanied by a sustained increase of S-nitrosoglutathione, a source of bioavailable NO, by 0.23 nmol/L (p < 0.001) (50). Flavanols, and particularly flavanol-rich cocoa, elevate NO bioavailability by both stimulating the NO synthase (eNOS) activity (82,83) and increasing the availability of l-arginine (via reduction of its degradation by arginase) (84). Furthermore, in a rat model, flavanols prevented the elevation of BP induced by l-nitroarginine methyl ester (l-NAME), a powerful inhibitor of NOS (83).…”

“…Flavanols, and particularly flavanol-rich cocoa, elevate NO bioavailability by both stimulating the NO synthase (eNOS) activity (82,83) and increasing the availability of l-arginine (via reduction of its degradation by arginase) (84). Furthermore, in a rat model, flavanols prevented the elevation of BP induced by l-nitroarginine methyl ester (l-NAME), a powerful inhibitor of NOS (83). In addition, cocoa showed a similar inhibitor effect on endothelin-1 production, a powerful vasoconstrictor (85,86).…”