Inclusion Criteria

DISEASE CHARACTERISTICS:

- Histologically confirmed adenocarcinoma of the prostate

- Must have completed prior surgery, cryotherapy, or radiotherapy for the primary tumor

- Documented rising prostate-specific antigen (PSA)

- Absolute level of PSA > 0.2 ng/mL after surgery

- Absolute level of PSA > 1.0 ng/mL after radiation or cryotherapy

- Absolute level of PSA ≥ 0.4 ng/mL after multiple treatment modalities (e.g.,
surgery with radiotherapy or radiotherapy with cryotherapy)

- PSA must be ≥ 100% above best nadir achieved

- PSA doubling time > 3 months or ≤ 24 months

- Patients must have ≥ 3 rising PSA time points above the minimum nadir
achieved over ≥ 6 months

- The interval between PSA time points must be > 2 weeks

- PSA ≤ 7.0 ng/mL

- Patients who underwent radical prostatectomy and never achieved undetectable serum
PSA after surgery are not eligible

- Gleason score ≤ 7

- No histologically positive lymph nodes

- No evidence of metastatic disease by physical examination, CT scan, or bone scan

PATIENT CHARACTERISTICS:

- Life expectancy ≥ 6 months

- ECOG performance status 0 or 1

- No significant concomitant medical or psychiatric conditions that would limit study
compliance

- No known allergies to pomegranate extract

- No known diabetes with hemoglobin A_1c level > 7.0% in the past 3 months

- Diabetic patients entering study who have not had hemoglobin A_1c level measured
in the past 3 months must have levels measured at study initiation

- No clinically abnormal laboratory values > 2 times the upper limit of normal

PRIOR CONCURRENT THERAPY:

- See Disease Characteristics

- More than 4 weeks since prior and no concurrent experimental drugs, high-dose
steroids, or other cancer treatment

- No hormonal therapy, with the exception of neoadjuvant androgen-deprivation therapy
(ADT), prior to or concurrent with primary therapy

- Patients who received prior neoadjuvant ADT must have serum testosterone ≥ 150
ng/dL

- No prior or concurrent hormonal therapy for rising PSA after primary therapy for
prostate cancer

- No finasteride or dutasteride at any time point after primary therapy and during
study therapy

- No other concurrent commercial pomegranate products

- No other concurrent systemic or local therapy for prostate cancer

- Concurrent dietary/herbal supplements (e.g., saw palmetto or selenium) allowed
provided dose has been stable for ≥ 2 months prior to study entry and there are no
plans to change or stop the supplements during study therapy