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Il cioccolato amaro migliora l'arteriopatia obliterante

Quaranta grammi di cioccolato nero sono in grado di aumentare il periodo libero nei pazienti con arteriopatia obliterante degli arti inferiori? Sembrerebbe di sì. E' questo quanto dimostrato da un gruppo di ricercatori romani che partendo dal fatto che nell'arteriopatia obliterante sono coinvolte le arterie di resistenza, le arteriole ed i capillari distali alla sede della stenosi arteriosa, ipotizzano la disfunzione endoteliale, la ridotta produzione di ossido nitrico e lo stress ossidativo come fenomeni implicati nella claudicatio intermittens. Il cacao, grazie al suo alto contenuto in polifenoli è in grado di aumentare la vasodilatazione arteriosa e di aumentare la produzione di ossido nitrico. Dopo 2 ore dall'ingestione del cioccolato, il tempo massimo di camminata migliora, come migliora l'ossido nitrico ed i parametri di vasodilatazione. Questo non succede con il cioccolato al latte.

Dark Chocolate Acutely Improves Walking Autonomy in Patients With Peripheral Artery Disease

Loffredo L, Perri L, Catasca E, Pignatelli P, Brancorsini M, Nocella C, De Falco E, Bartimoccia S, Frati G, Carnevale R, Violi F

J Am Heart Assoc. 2014;3:e001072

Background: NOX-2, the catalytic subunit of NADPH oxidase, has a key role in the formation of reactive oxidant species and is implicated in impairing flow-mediated dilation (FMD). Dark chocolate exerts artery dilatation via down-regulating NOX2-mediated oxidative stress. The aim of this study was to investigate whether dark chocolate improves walking autonomy in peripheral artery disease (PAD) patients via an oxidative stress-mediated mechanism.
Methods and Results: FMD, serum levels of isoprostanes, nitrite/nitrate (NOx) and sNOX2-dp, a marker of blood NOX2 activity, maximal walking distance (MWD) and maximal walking time (MWT) were studied in 20 PAD patients (14 males and 6 females, mean age: 69,9 years) randomly allocated to 40 g of dark chocolate (>85% cocoa) or 40 g of milk chocolate (=35% cocoa) in a single blind, cross-over design. The above variables were assessed at baseline and 2 hours after chocolate ingestion. Dark chocolate intake significantly increased MWD (+11%; P<0.001), MWT (+15%; P<0.001), serum NOx (+57%; P<0.001) and decreased serum isoprostanes (23%; P=0.01) and sNOX2-dp (37%; P<0.001); no changes of the above variables were observed after milk chocolate intake. Serum epicatechin and its methylated metabolite significantly increased only after dark chocolate ingestion. Multiple linear regression analysis showed that D of MWD was independently associated with D of MWT (P<0.001) and D of NOx (P=0.018). In vitro study demonstrated that HUVEC incubated with a mixture of polyphenols significantly increased nitric oxide (P<0.001) and decreased E-selectin (P<0.001) and VCAM1 (P<0.001).
Conclusion: In PAD patients dark but not milk chocolate acutely improves walking autonomy with a mechanism possibly related
to an oxidative stress-mediated mechanism involving NOX2 regulation.

J Am Heart Assoc. 2014;3:e001072