Dark chocolate intake significantly increased MWD ( +11 % ; P < 0.001 ) , MWT ( +15 % ; P < 0.001 ) , serum NOx ( +57 % ; P < 0.001 ) and decreased serum isoprostanes ( -23 % ; P = 0.01 ) and sNOX2-dp ( -37 % ; P < 0.001 ) ; no changes of the above variables were observed after milk chocolate intake .