National Food Agency of Denmark, Mørkhøj Bygade, Søborg.
Eighteen volunteers received 500 g fresh broccoli every day for 12 days after a 6-day period of standard diet. The activity of CYP1A2, CYP2E1 and the estrone 2 and 16alpha-hydroxylation were determined prior to and after the broccoli diet. The average activity of CYP1A2 and the average 2/16alpha-hydroxyestrone ratio were increased 19% (P < 0.0005) and 29.5% (P < 0.05), respectively; however, no effects were observed on the CYP2E1 activity.