Effect of dark chocolate on plasma epicatechin levels, DNA resistance to oxidative stress and total antioxidant activity in healthy subjects

Dark chocolate (DC) may be cardioprotective by antioxidant properties of flavonoids. We investigated the effect of DC (860 mg polyphenols, of which 58 mg epicatechin) compared with white chocolate (WC; 5 mg polyphenols, undetectable epicatechin) on plasma epicatechin levels, mononuclear blood cells (MNBC) DNA damage and plasma total antioxidant activity (TAA). Twenty healthy subjects followed a balanced diet (55% of energy from carbohydrates, 30% from fat and 1 g protein/kg body weight) for 4 weeks. Since the 14th clay until the 27th day, they introduced daily 45 g of either WC (n 10) or DC (n 10). Whole experimental period was standardised in antioxidant intake. Blood samples were collected at To, after 2 weeks (T-14), 2h and 22h after the first chocolate intake (T14+2h and T14+22h), and at 27th day, before chocolate intake (T-27), 2h and 22h after (T27+2h and T27+22h). Samples, except for T14+2h and T27+2h, were fasting collected. Detectable epicatechin levels were observed exclusively 2h after DC intake (T14+2h = 0.362 (SE 0.052) mu mol/l and T27+2h = 0.369 (SE 0.041) mu mol/l); at the same times corresponded lower MNBC DNA damages (T14+2h = 19.4 (SE 3.4)% v. T-14, P<0.05; T27+2h = -24 (SE 7.4)% v. T-27, P<0.05; T14+2h v. T27+2h, P=0.7). Both effects were no longer evident after 22 h. No effect was observed on TAA. WC did not affect any variable. DC may transiently improve DNA resistance to oxidative stress, probably for flavonoid kinetics.