Prostate cancer affects mainly older men. Six out of ten cases are diagnosed in men over 65, but less than 1% in men under 50. Though uncommon, prostate cancer can be seen in men even in their 30's and 40's. Men with a family history of prostate cancer are more likely to develop prostate cancer than the general population.
On a case-by-case basis, doctors cannot say with certainty what causes prostate cancer, but experts generally agree that diet contributes to the risk. Men who consume large amounts of fat -- particularly from red meat and other sources of animal fat cooked at high heat -- may be more likely to develop advanced prostate cancer. The disease is much more common in countries where meat and dairy products are dietary staples than in countries where the basic diet consists of rice, soybean products, and vegetables such as broccoli, cauliflower, cole slaw, or sauerkraut.
The underlying factor linking diet and prostate cancer is probably hormonal. Fats stimulate increased production of testosterone and other hormones, and testosterone acts to speed the growth of prostate cancer. High testosterone levels may stimulate dormant prostate cancer cells into activity. Some findings suggest that high testosterone levels also influence the initial onset of prostate cancer.
Welders, battery manufacturers, rubber workers, and workers frequently exposed to the metal cadmium seem to be abnormally vulnerable to prostate cancer.
The following are also associated with an increased risk of advanced prostate cancer: Height, high body mass index, low physical activity, smoking, low tomato sauce consumption, high calcium intake, high linoleic acid intake, African-American race, and a positive family history.
No proven link exists between prostate cancer and an active sex life, vasectomy, masturbation, use of alcohol or tobacco, circumcision, infertility, infection of the prostate, or a common noncancerous condition called benign prostatic hyperplasia (BPH). Most, if not all, men will experience an enlarged prostate as they age.