Study of Acai Juice in Asymptomatic or Minimally Symptomatic Prostate Cancer Patients With Rising PSA

Inclusion Criteria: * Histologically confirmed prostate adenocarcinoma. * Evidence of rising PSA, on 2 separate occasions, at least one week apart. * Baseline PSA must be ≥ 0.2 ng/mL at the time of screening. Radiographic evidence of disease is not required. * Patients must have sufficient PSA time points prior to enrollment (a minimum of 3 PSA levels within a six month period) to calculate a baseline PSA doubling time. * Patients may not be on active Luteinizing Hormone Releasing Hormone (LHRH) agonist therapy and must have testosterone level \> 50 ng/dL. * Patients must not be on active anti-androgen therapy or 5-alpha reductase inhibitors. However, patients who have been on a stable dose of 5-alpha reductase inhibitor for benign prostatic hypertrophy for at least 6 months may continue taking this agent. * Patients who are on active surveillance for localized disease may participate in this study. * Patients who are candidates for local salvage therapy must have had this option pursued or discussed; and the patient must have either declined salvage therapy or was deemed not to be a candidate for salvage therapy. * Patients who have PSA recurrence after local salvage therapy may participate in this study. * Patients with hormone sensitive disease who received prior androgen deprivation therapy as part of primary/salvage local treatment or patients receiving intermittent androgen deprivation therapy will be allowed to participate. * Eastern Cooperative Oncology Group (ECOG) performance status 0-2. * Adequate hematologic function (absolute neutrophil count (ANC) ≥ 1,500 cells/µL; hemoglobin ≥ 9 g/dL, platelets ≥ 75,000/µL). * Adequate renal function (serum creatinine ≤ 2 X the ULN). * Adequate hepatic function (total bilirubin ≤ 2 x upper limit of normal (ULN), alanine aminotransferase (ALT) ≤ 3 x ULN, aspartate aminotransferase (AST) ≤ 3 x ULN). * Agree not to take any other forms of natural or herbal supplements during study duration. * Chemotherapy for prostate cancer is allowed as long as it was not given for hormone-refractory disease. Exclusion Criteria: * Inability to swallow liquids, or any medical condition that interferes with normal gastrointestinal absorption. * Major surgery, radiation, or treatment with any other investigational drug within 2 weeks of study treatment. * Documented hypersensitivity reaction to acai or any product contained in Acai Juice (see complete list in Appendix 1). * Uncontrolled intercurrent disease (e.g. diabetes, hypertension, thyroid disease, coronary artery disease). * Known chronic infection with human immunodeficiency virus (HIV) or viral hepatitis. * Symptomatic prostate cancer as determined by cancer-related pain requiring narcotic pain medication. * History of another cancer is exclusionary unless it is believed to be likely cured or is unlikely to be fatal in the next 3 years (e.g. squamous cell carcinoma, superficial bladder cancer, chronic lymphocytic leukemia, etc). * Very fast PSA doubling time of less than 4 weeks, if the absolute PSA is \> 2 ng/mL.