Dose-response study of daily cocoa intake on the oxadative susceptibility of low-density lipoprotein in healthy human volunteers

A four-period crossover study was conducted to evaluate the dose-related response of daily cocoa intake on the oxidative susceptibility of low-density lipoprotein (LDL) in healthy human volunteers. Each supplementation phase consisted of a 14-day feeding period followed by a 28-day washout period. During the period, healthy male volunteers (n = 8) ingested 18, 24 or 36 g of cocoa powder per day (1.3, 1.74 or 2.61g of polyphenols per day). During the control period, these subjects ingested sugar. LDL oxidative susceptibility was measured as the lag time of conjugated diene formation that started with the addition of a radical initiator, 2,2'-azobis (4-methoxy-2,4-dimethylvaleronitrile). Samples were analyzed at pre-, one week, and two weeks post-supplementation. In the 24 and 36 g cocoa powder ingestion period, significant lag time prolongation was observed. We conclude that the ingestion of more than 24 g of cocoa powder per day (1.74 g of polyphenols) clearly protects LDL from oxidation.