Dose-response study of daily cocoa intake on the oxidative 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 2.61 g 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-dimethyl-valeronitrile). 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.