Healthy individuals (n=18) will participate in 2 controlled-feeding study periods that are 3 weeks each in length: 1) Control diet 2) Brassica diet. The control diet will consist of typical American foods and will be free of Brassica vegetables and free of glucosinolates and isothiocyanates. The Brassica diet will contain the control diet plus glucosinolate/isothiocyanate treatment foods. There will be a break of 3 weeks in between study periods. Blood, urine, and fecal samples will be collected at the end of each study period. Eligible participants will be selected based on genotype for glutathione S-transferase (GST), which has been shown to influence the potential protective role of dietary Brassicas. Half the participants (n=9) will be GSTM1-positive individuals and half (n=9) will have the GSTM1-null genotype.