Pomegranate-Extract Pill in Preventing Tumor Growth in Patients With Localized Prostate Cancer Undergoing Active Surveillance

Inclusion Criteria:

* Participants must have had a standard-of-care biopsy within 13 months of the baseline study visit and must have been diagnosed with low-grade, clinically localized prostate cancer (Gleason score =\< 3+3 with a PSA at baseline \< 10 ng/ml in participants \< 70 years of age, OR Gleason score =\< 3+4 with a PSA at baseline =\< 15 ng/ml in participants \>= 70 years of age); eligible participants will be those men who are able and willing to undergo AS with PSA monitoring and a scheduled biopsy performed at the end of the study
* No concurrent treatment (hormonal, radiation or systemic chemotherapy) for prostate cancer during study enrollment is planned (unless participants demonstrate clinical evidence of prostate cancer progression such as symptoms, physical exam findings, a rapidly increasing PSA, or radiologic findings which confirm disease progression)
* Eastern Cooperative Oncology Group (ECOG) performance status =\< 1
* White blood cells (WBC) \>= 3000/mm\^3
* Platelets \>= 100,000 mm\^3
* Hemoglobin \>= 10 g/dL
* Total bilirubin =\< 1.5 x upper limit of institutional normal
* Alkaline phosphatase =\< 1.5 x upper limit of institutional normal
* Aspartate aminotransferase (AST) =\< 1.5 x upper limit of institutional normal
* Alanine aminotransferase (ALT) =\< 1.5 x upper limit of institutional normal
* Serum creatinine within 1.5 x upper limit of institutional normal
* Sodium 135-144 mmol/L (inclusive)
* Potassium 3.2-4.8 mmol/L (inclusive)
* Participants will be required to use a medically-approved method of birth control or abstinence if their sexual partner is of child-bearing potential
* Participants must be willing to forego foods, beverages and supplements containing pomegranate for the duration of the study
* Ability to understand, and the willingness to sign, a written informed consent document

Exclusion Criteria:

* Any prior surgery to the prostate within 30 days of baseline procedures; NOTE: Biopsies are not considered surgeries
* Evidence of other cancer(s) (excluding non-melanoma skin cancer) within last 5 years
* Prior pelvic radiation for any reason
* Participants cannot be taking 5-alpha-reductase inhibitors while on study or within 6 months of the baseline study visit
* Participants may not be taking carbamazepine (tegretol)
* Participants may not be receiving any other investigational agents
* History of allergic reactions attributed to compounds of similar chemical or biologic composition to PFE
* Uncontrolled intercurrent illness including, but not limited to, ongoing or active infection, or psychiatric illness/social situations that would limit compliance with study requirements
* Any significant cardiac event(s) within the 12 months prior to registration, such as episode(s) of symptomatic congestive heart failure, myocardial infarction, unstable angina pectoris or persistent, stable angina pectoris, or cardiac arrhythmia requiring medication