This study focuses on patients who have been diagnosed with prostate cancer and plan to undergo radical prostatectomy (surgery to remove the prostate gland and surrounding tissues). The purpose of the study is to examine the effects of daily walnut intake on the growth of prostate cancer by measuring changes in the proliferative index (an indicator of disease severity) in biopsy and surgical tissue. The proliferative index is a measure of the number of cells in a tumor that are dividing, which can indicate how fast a tumor is growing. Researchers aim to determine whether daily walnut consumption will slow prostate cancer growth compared to no daily walnut consumption in men with prostate cancer who are scheduled to undergo radical prostatectomy.

Participants will be randomly assigned to one of two study groups. The first group will be asked to consume 2 ounces of walnuts per day, in addition to their regular diet. The second group will follow their usual diet.

• CS Cancer at Cedars-Sinai Medical Center