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 day 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 T0, after 2 weeks (T14), 2 h and 22 h after the first chocolate intake (T14þ 2h and T14þ22 h), and at 27th day, before chocolate intake (T27), 2 h and 22 h after (T27þ 2h and T27þ22 h). Samples, except for T14þ 2h and T27þ 2h , were fasting collected. Detectable epicatechin levels were observed exclusively 2 h after DC intake (T14þ 2h ¼ 0·362 (SE 0·052)mmol/l and T27þ 2h ¼ 0·369 (SE 0·041)mmol/l); at the same times corresponded lower MNBC DNA damages (T14þ 2h ¼ 219·4 (SE 3·4) % v. T14, P,0·05; T27þ 2h ¼ 2 24 (SE 7·4) % v. T27, P, 0·05; T14þ 2h v. T27þ 2h , P¼ 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.