Inclusion Criteria:

- Diagnosis of localized CaP, based on pathological assessment from biopsy specimens

- No prior or current therapy for CaP or history of cancer except non-melanoma skin
cancer

- Scheduled for prostatectomy between 4- 6 weeks (+/-3 days) after start of study agent

- No known history of hepatic or renal disease (LFTs (SGOT/SGPT) > 5.0 x upper limit of
normal as evidenced by impairment of baseline laboratory values, Actual creatinine
clearance of >60 utilizing the Cockcroft-Gault formula (1976), which employs
creatinine measurements and a patient's weight to predict the clearance. The constant
is 1.23 for men.

- Omnivorous diet

- No evidence of prostatitis or urinary tract infection

- Able and willing to give written informed consent

- Currently not using or willing to discontinue any nutritional supplements that
contain soy or soy isoflavones

- Not allergic to study supplements

- Not on antibiotics

- Men who do not consume more than 3 - 4 oz of soy or soy products per week

- Not taking steroid hormones or medications which have known impact on PSA

- Health status cleared by primary MD or urologist

- Eastern Cooperative Oncology Group (ECOG) performance status of 0-1

Exclusion Criteria:

- Prior history of prostate cancer; Current or prior history of other malignancies
(exceptions include nonmelanoma skin cancer or other cancer with no evidence of tumor
recurrence five years after definitive treatment)

- History of renal or hepatic disease, including history of hepatitis B, C or delta as
evidenced by impairment of baseline laboratory values

- Participation in any other investigational study or use of any other investigational
agents within 30 days of study entry

- History of allergic reactions attributed to soy isoflavones or other compounds of
similar chemical or biologic composition to Novasoy 400® or the inactive components
present in the purified isoflavone and placebo capsules

- Uncontrolled intercurrent illness including, but not limited to, ongoing or active
infection, symptomatic congestive heart failure, unstable angina pectoris, cardiac
arrhythmia, or any psychological, familial, sociological or other concomitant
condition that would not allow adequate compliance with the study protocol

- Only African American (a person having origins in any of the black racial groups of
Africa) and Caucasian (a person having origins in any of the original people of
Europe, Middle East, or North Africa) men, as defined by the NIH, will be included in
this study. Since this is an investigation targeting men with CaP, women are not
eligible for the study.