They were only forbidden to partake of the Tree of Knowledge of Good and Evil. Some of the best information we have on the Tree of Life comes from I Nephi 11. Nephi is trying to obtain the interpretation of the dream his father had.
Factors that increase the risk of prostate cancer include: older age, a family history of the disease, and race. About 99% of cases occur in those over the age of 50. Having a first-degree relative with the disease increases the risk two to threefold.
Many of the symptoms of prostate cancer relate to the enlargement of the gland, so they are not specific to prostate cancer and can be caused by other conditions like benign prostatic hyperplasia, which enlarges the prostate gland.