Lycopene or Omega-3 Fatty Acid Nutritional Supplements in Treating Patients With Stage I or Stage II Prostate Cancer

DISEASE CHARACTERISTICS: * Histologically confirmed adenocarcinoma of the prostate meeting the following criteria: * Newly diagnosed disease * Small cell acinar type * Gleason score ≤ 6 with no pattern 4 or 5 histology * Gleason pattern 4 seen as a microfocus (\< 2 mm in length) allowed * Stage I-II (T1 or T2a) disease * Must have had an extended pattern biopsy (defined as 8+ cores) within the past 2 years * Patients meeting all of the eligibility criteria except for the aforementioned extended pattern biopsy within the past two years may enroll in the study if they have an extended pattern clinical biopsy scheduled no more than 6 weeks before beginning study treatment AND are willing to have an additional 4 biopsy cores * No more than 33% of biopsy cores positive * 33% or more of biopsy cores positive due to microfoci of adenocarcinoma allowed * No more than 50% of the length of a tumor core involved by carcinoma * Watchful waiting planned as primary treatment strategy * Must have 3 serum prostate-specific antigen (PSA) level readings taken ≥ 2 weeks apart over the past year * PSA ≤ 10.0 ng/mL * PSA \< 15 ng/mL in patients with benign prostatic hyperplasia or prostatitis allowed * PSA doubling time ≥ 3 months PATIENT CHARACTERISTICS: * Life expectancy ≥ 3 months * ECOG performance status 0-2 * No history of allergic reactions attributed to tomatoes, fish, soybean oil, gelatin capsules, or compounds of similar chemical or biologic composition to lycopene (carotenoids) or fish oil (omega-3 fatty acids) * No uncontrolled intercurrent illness including, but not limited to, the following: * Ongoing or active infection * Symptomatic congestive heart failure * Unstable angina pectoris * Cardiac arrhythmia * Psychiatric illness or social situations that would limit study compliance PRIOR CONCURRENT THERAPY: * No prior or concurrent treatment for prostate cancer, including surgery, radiation, hormonal therapy (e.g., leuprolide acetate, bicalutamide, flutamide, goserelin, megestrol, nilutamide, diethylstilbestrol/estrogen), chemotherapy, PC-SPES, or investigational agents * More than 4 weeks since prior and no concurrent lycopene, fish oil (omega-3 fatty acids), or any other preparation intended to supplement levels of omega-3 unsaturated fatty acids * More than 4 weeks since prior and no concurrent finasteride, dutasteride, saw palmetto or any other herbal/nutritional preparation indicated to affect hormone levels * More than 1 month since prior nonsteroidal anti-inflammatory drugs (NSAIDs), cyclooxygenase-2 (COX-2) inhibitors, and/or aspirin for \> 7 days duration * No concurrent NSAIDs, COX-2 inhibitors, or aspirin