Effect of consumption of dark chocolate on lipoproteins and serum lipids

Background and aim  Epidemiological studies suggest that regular consumption of foods and beverages rich in flavonoids is associated with a decreased risk of cardiovascular mortality. Cocoa, the main ingredient of chocolate, is rich in polyphenols. The aim of this study was to investigate the effects of consumption of 50 g daily for 3 weeks of flavonoid-rich dark chocolate on lipoprotein oxidative stress in vitro and in vivo. In particular, levels of thiobarbituric acid-reactive substances (TBARS), conjugated dienes, lipoperoxide and hydroperoxide in HDL and LDL before and after consumption of flavonoid-rich dark chocolate were assessed. The serum lipid profile was also studied. Methods and results  Ten healthy Italian-Caucasian volunteers were recruited without restriction as to age, gender, or socioeconomic status. Their BMI was between 21 and 26 kg/m², and the subjects included men and premenopausal women. The study protocol was conducted in accordance with the principles of the Declaration of Helsinki as revised in 2001, and all subjects gave written informed consent. TBARs concentrations, lipid hydroperoxides as determined using the FOX assay, and conjugate formation in HDL and in LDL were significantly decreased after 3 weeks of dark chocolate consumption with respect to the baseline values. To summarize, the present study showed favourable effects of chocolate consumption both on HDL cholesterol, and on some of the lipid peroxidation markers such as conjugated dienes, lipid hydroperoxides (FOX assay) and TBARS. Similar results were obtained with regard to LDL fractions. Our study also showed that 3 weeks consumption of dark chocolate might improve endothelial function in healthy humans and might exert a protective effect on the cardiovascular system.