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I flavanoli migliorano la funzione endoteliale

I flavanoli appartengono alla famiglia dei flavonoidi, sono presenti naturalmente nel cacao, ma vengono in gran parte persi nel processo di lavorazione per la produzione del cioccolato. Vari studi controllati condotti sull'uomo hanno dimostrato che alimenti e bevande contenenti flavanoli sono in grado di migliorare la funzione endoteliale e di ridurre la pressione arteriosa e l'aggregazione piastrinica. Heiss e Coll. hanno dimostrato che la somministrazione giornaliera di bevande contenenti cacao determina, in pazienti con cardiopatia ischemica, la mobilizzazione dal midollo di cellule angiogeniche. Queste, che sono considerate cellule progenitrici delle cellule endoteliali, contribuiscono alla riparazione dell'endotelio danneggiato a seguito dell'insulto vascolare. Uno dei principali effetti del danno endoteliale è la riduzione della produzione di ossido nitrico e la riparazione dell'endotelio potrebbe spiegare, proprio attraverso l'aumento della biodisponibilità di ossido nitrico, gli effetti emodinamici osservati dopo assunzione di flavanoli.

Improvement of endothelial function with dietary flavanols is associated with mobilization of circulating angiogenic cells in patients with coronary artery disease

Heiss C, Jahn S, Taylor M, Real WM, Angeli FS, Wong ML, Amabile N, Prasad M, Rassaf T, Ottaviani JI, Mihardja S, Keen CL, Springer ML, Boyle A, Grossman W, Glantz SA, Schroeter H, Yeghiazarians Y.

J Am Coll Cardiol 2010;56:218-24

OBJECTIVES: In patients with coronary artery disease (CAD) medically managed according to currently accepted guidelines, we tested whether a 1-month dietary intervention with flavanol-containing cocoa leads to an improvement of endothelial dysfunction and whether this is associated with an enhanced number and function of circulating angiogenic cells (CACs).
BACKGROUND: Dietary flavanols can improve endothelial dysfunction. The CACs, also termed endothelial progenitor cells, are critical for vascular repair and maintenance of endothelial function.
METHODS: In a randomized, controlled, double-masked, cross-over trial, 16 CAD patients (64+/-3 years of age) received a dietary high-flavanol intervention (HiFI [375 mg]) and a macronutrient- and micronutrient-matched low-flavanol intervention (LoFI [9 mg]) twice daily in random order over 30 days.
RESULTS: Endothelium-dependent vasomotor function, as measured by flow-mediated vasodilation of the brachial artery, improved by 47% in the HiFI period compared with the LoFI period. After HiFI, the number of CD34+/KDR+-CACs, as measured by flow cytometry, increased 2.2-fold as compared with after LoFI. The CAC functions, as measured by the capacity to survive, differentiate, proliferate, and to migrate were not different between the groups. The HiFI led to a decrease in systolic blood pressure (mean change over LoFI: -4.2+/-2.7 mm Hg), and increase in plasma nitrite level (mean change over LoFI: 74+/-32 nM). Applying a mixed-effects linear regression model, the results demonstrated a significant increase in flow-mediated vasodilation and a decrease in systolic blood pressure with increasing levels of CD34+/KDR+-CACs.
CONCLUSIONS: Sustained improvements in endothelial dysfunction by regular dietary intake of flavanols are associated with mobilization of functional CACs. (Effect of Cocoa Flavanols on Vascular Function in Optimally Treated Coronary Artery Disease Patients: Interaction Between Endothelial Progenitor Cells, Reactivity of Micro- and Macrocirculation; NCT00553774).

J Am Coll Cardiol 2010;56:218-24