Cocoa consumption dose-dependently improves flow-mediated dilation and arterial stiffness decreasing blood pressure in healthy individuals.
BACKGROUND
Cocoa flavonoids exert beneficial vascular effects and reduce the risk of cardiovascular morbidity and mortality. Nevertheless, the involved mechanisms have not been clarified and no study has yet focused on the dose-response effects.


OBJECTIVE
We aimed to investigate the effects of different doses of cocoa flavonoids on flow-mediated dilation (FMD), endothelin-1 (ET-1), pulse wave velocity (PWV), and SBP and DBP.


METHODS
According to a randomized, double-blind, controlled, cross-over design, 20 healthy volunteers (1.5% improvement in FMD in 20 individuals: 0.99 at alpha = 0.05) were assigned to receive either five treatments with daily intake of 10 g cocoa (0, 80, 200, 500 and 800 mg cocoa flavonoids/day) in five periods lasting 1 week each.


RESULTS
Cocoa dose-dependently increased FMD from 6.2% (control) to 7.3, 7.6, 8.1 and 8.2% after the different flavonoid doses, respectively (P < 0.0001). Compared with the control, even 80  mg cocoa flavonoids per day increased FMD (P < 0.0001). Cocoa dose-dependently decreased PWV (P < 0.0001). Cocoa intake decreased office blood pressure (BP) (SBP: -4.8 ± 1.03  mmHg, P < 0.0001; DBP: -3.03 ± 1.07 mmHg, P = 0.0011). With respect to control, cocoa ingestion decreased 24-h (P = 0.05) and daytime (P = 0.038) SBP, and 24-h (P = 0.0064), daytime (P = 0.0088) and night-time (P = 0.0352) pulse pressure. Compared with the control, cocoa dose-dependently decreased ET-1 levels [from 17.1 (control) to 15.2, 14.5, 14.2 and 14.1 pg/ml, after the different flavonoid doses, respectively (P for treatment <0.05)]. Compared with the control, significant changes were observed for all doses of flavonoids (ET-1; P < 0.05).


CONCLUSIONS
Our study showed for the first time that cocoa dose-dependently improved FMD and decreased PWV and ET-1 also by ameliorating office and monitored BP. Our findings are clinically relevant, suggesting cocoa, with very low calorie intake, might be reasonably incorporated into a dietary approach, representing a consistent tool in cardiovascular prevention.
aDepartment of Life, Health and Environmental Science, University of L'Aquila, L'Aquila, Italy bBarry Callebaut, Lebbeke-Wieze, Belgium.
Davide
D
Grassi
Giovambattista
G
Desideri
Stefano
S
Necozione
Paolo
P
di Giosia
Remo
R
Barnabei
Leen
L
Allegaert
Herwig
H
Bernaert
Claudio
C
Ferri
D000328:Adult; D001794:Blood Pressure / Q000187:drug effects*; D018660:Blood Pressure Monitoring, Ambulatory; D002099:Cacao; D018592:Cross-Over Studies; D004311:Double-Blind Method; D019332:Endothelin-1 / Q000097:blood; D004730:Endothelium, Vascular / Q000187:drug effects; D005419:Flavonoids / Q000008:administration & dosage* / Q000032:analysis; D064368:Healthy Volunteers; D006801:Humans; D007333:Insulin Resistance; D050356:Lipid Metabolism / Q000187:drug effects; D008297:Male; D008875:Middle Aged; D008517:Phytotherapy; D028321:Plant Preparations / Q000008:administration & dosage / Q000737:chemistry; D063177:Pulse Wave Analysis; D059289:Vascular Stiffness / Q000187:drug effects*
D019332:Endothelin-1; D005419:Flavonoids; D028321:Plant Preparations