In a randomized crossover trial , healthy men ( n = 32 ) and women ( n = 31 ) aged 20-40 y consumed 4 14-d controlled diets : basal ( vegetable-free ) , single-dose cruciferous ( 1xC ) [ 7 g vegetables/kg body weight ( BW ) ] , double-dose cruciferous ( 2xC ) ( 14 g/kg BW ) , and cruciferous plus apiaceous ( carrot family ) ( 1xC + A ) vegetables ( 7 and 4 g/kg BW , respectively ) , with a 21-d washout period between each intervention .