Effect of consumption of dark chocolate on oxidative stress in lipoproteins and platelets in women and in men

► Flavanol beneficial effects on inflammation has implications to cardiovascular disease. ► Cocoa can be defined as a functional food due to its high content of monomeric and oligomeric flavanols. ► This research shows the effects of supplementation with dark chocolate on the production of free radicals. ► An intake of chocolate might improve lipoproteins profile, might exert a protective effect on the cardiovascular system. ► An intake of chocolate might improve platelets profile, might exert a protective effect on the cardiovascular system. The goal of this research was to investigate the effects of 3 weeks consumption of 50 g flavonoid-rich dark chocolate on lipoprotein oxidative stress in vitro and in vivo in 25 women compared to 25 men. Levels of thiobarbituric acid-reactive substances, conjugated dienes and hydroperoxide levels in HDL and LDL before and after consumption of dark chocolate were determined. Moreover in platelets of the same subjects NO and peroxynitrite levels were studied. TBARs concentration in women’s HDL decreased by 26.7% while in men’s HDL 23.4%; lipid hydroperoxides decreased in women’s HDL by 62.8% while in men’s HDL they decreased by 21.1%. Conjugate diene formation decreased in women’s HDL by 55.9%, while in men’s HDL it decreased by 49.2%. Moreover TBARs concentration decreased in women’s LDL by 26.7% after supplementation and in men’s LDL by 21.6%; lipid hydroperoxides decreased in women’s LDL by 83.6% while in men’s LDL they decreased by 64.7%. Moreover conjugate diene formation decreased in women’s LDL by 48.2%, while in men’s LDL it decreased by 21.6%. After supplementation peroxynitrite values decreased in women by 24% and in men by 18.6% while NO increased after supplementation by 15.7% compared to basal determination in women, and by 32.2% in men. This study showed that a short-term intake of dark chocolate might improve the lipoprotein profile in healthy humans, more so in women than in men, and this might exert a protective effect on the cardiovascular system.