MILAN, Italy—Dark chocolate improved DNA resistance to oxidative stress and researchers say this effect is most likely due to its flavonoid content, according to a study published in the British Journal of Nutrition (2009 Nov 5:1-7).
Researchers investigated the effect of dark chocolate that contained 860 mg polyphenols, of which 58 mg were epicatechin, compared with white chocolate, which had 5 mg polyphenols and undetectable amounts of epicatechin in 20 healthy subjects. The subjects followed a balanced diet (55 percent of energy from carbohydrates, 30 percent from fat and 1 g protein/kg body weight) for four weeks. On the 14th day until the 27th day, researchers gave 45 g of either white (n 10) or dark chocolate (n 10).
At the end of the study, detectable epicatechin levels increased two hours after subjects ate dark chocolate (0.369 (se 0.041) mumol/l) and mononuclear blood cells DNA damage decreased 20 percent from two weeks into the study (- 19.4 (se 3.4) % at day 14 v. - 24 (se 7.4) % on day 27, P = 0.7). While both effects were no longer evident 22 hours after eating the dark chocolate, no effect was observed in the white chocolate group.