Effects of cocoa powder and dark chocolate on LDL oxidative susceptibilityand prostaglandin concentrations in humans

Background: Flavonoids are polyphenolic compounds of plant origin with anti oxidant effects. Flavonoids inhibit LDL oxidation and reduce thrombotic ten dency in vitro. Little is known about how cocoa powder and dark chocolate, rich sources of polyphenols, affect these cardiovascular disease risk facto rs. Objective: We evaluated the effects of a diet high in cocoa powder and dark chocolate (CP-DC diet) on LDL oxidative susceptibility, serum total antiox idant capacity, and urinary prostaglandin concentrations. Design: We conducted a randomized, 2-period, crossover study in 23 healthy subjects fed 2 diets: an average American diet (AAD) controlled for fiber, caffeine, and theobromine and an AAD supplemented with 22 a cocoa powder an d 16 g dark chocolate (CP-DC diet), providing approximate to 466 mg procyan idins/d. Results: LDL oxidation lag time was approximate to8% greater (P = 0.01) aft er the CP-DC diet than after the AAD. Serum total antioxidant capacity meas ured by oxygen radical absorbance capacity was approximate to4% greater (P = 0.04) after the CP-DC diet than after the AAD and was positively correlat ed with LDL oxidation lag time (r = 0.32, P = 0.03). HDL cholesterol was 4% greater after the CP-DC diet (P = 0.02) than after the AAD; however, LDL-H DL ratios were not significantly different. Twenty-four-hour urinary excret ion of thromboxane B-2 and 6-keto-prostaglandin F-1 alpha and the ratio of the 2 compounds were not significantly different between the 2 diets. Conclusion: Cocoa powder and dark chocolate may favorably affect cardiovasc ular disease risk status by modestly reducing LDL oxidation susceptibility, increasing serum total antioxidant capacity and HDL-cholesterol concentrat ions, and not adversely affecting prostaglandins.