The investigators proposed to identify the biological effects of a high-sulforaphane broccoli sprout extract in normal prostate tissue.

The investigators hypothesize that consumption of high-sulforaphane broccoli sprout extract every other day will inhibit growth of prostate cancer cells.

Inclusion Criteria:

• Men aged 40-75 years
• Low or intermediate grade prostate cancer (as defined by Gleason sum less than or equal to 7) and clinical stage T1 or T2
• Serum Prostate specific antigen less than 20 ng/ml
• Have elected radical prostatectomy, Brachytherapy or active surveillance as their primary treatment

Exclusion Criteria:

• No current physician diagnosed disease (including but not limited to): kidney disease requiring dialysis, cognitive deficits, substance abuse
• BMI < 18.5 kg/m2 or > 40 kg/m2
• Use of any hormonal treatments, including but not limited to testosterone
• Any previous cancer diagnosis or treatment within the previous five years, excluding non-melanoma skin cancer
• Inability or unwillingness to eat a diet that is free of Brassica vegetables for the duration of the study
• Use of any dietary supplements other than a multivitamin (including herbal preparations)
• Allergy to cruciferous vegetables or any of the specific fillers used in the placebo
• Usual consumption of > 5 servings per week of Brassica vegetables

One participant enrolled to the placebo arm was determined to be ineligible, and was withdrawn from the study Two additional participants enrolled to the placebo arm became ineligible after enrollment, and were withdrawn from the study

Participants were asked to report the frequency/severity of gastrointestinal-related symptoms weekly.

Adverse event data for the sulforaphane arm is based only on 21 because all data/specimens for one participant (who was ineligible and mistakenly enrolled) was destroyed per Institutional Review Board regulations.