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Prostate cancer prevention is a "hot" area of medical research — the focus of several large-scale, long-term studies. This research holds exciting possibilities for the future and suggests some prostate cancer prevention strategies for you to use now.
As you decide what prevention strategies to adopt, keep in mind that several of the strongest known risk factors for prostate cancer are beyond your control. These include:
- Age. Prostate cancer is unusual in men under 50, but incidence of the disease increases dramatically after that age.
- Race. African-American men are at increased risk of prostate cancer.
- Genetics. Your risk of prostate cancer is higher if other men in your family have had the disease.
If you have these characteristics, it means only that your likelihood of developing prostate cancer is higher than that of a man without the characteristic. A 55-year-old African American man whose father had prostate cancer is still more likely to live out his life without prostate cancer than he is to develop it. The full range of factors that cause prostate cancer is still largely unknown.
Even if you don't have any of the three uncontrollable risk factors for prostate cancer, it pays to follow the lifestyle linked to a lower risk of the disease. The habits that protect against prostate cancer might help you to avoid other diseases as well — heart disease and colorectal cancer, for example. Find out which of these habits you've already adopted, and consider others you can make later on.
Much of the research on prostate cancer prevention focuses on nutrition. Key factors include:
- Fat. Prostate cancer rates vary greatly from one country to another, with the highest rates appearing in countries where people tend to eat a lot of fat. In fact, the number of prostate cancer deaths in a given country rises in direct proportion to the average total calories from fat in that country's typical diet.
- Vegetables. Some studies link a diet high in vegetables to a lower risk of prostate cancer. For example, one study found that men who ate 28 or more servings of vegetables each week had lower rates of prostate cancer compared to men who ate less than 14 servings.
- Fish. In one study, prostate cancer was two to three times more common in men who ate no fish as in men who ate moderate to large amounts of fish. Types of fish that are rich in the fatty acids that protect against prostate cancer and other diseases include salmon, herring, and mackerel.
So far, research does not support definite nutritional guidelines for preventing prostate cancer. However, you can reasonably act on these suggestions:
- Eat more fruits, vegetables and whole grains.
- Reduce intake of saturated fat and cholesterol.
- Limit sweets and salt.
- Drink alcoholic beverages in moderation, if at all.
- Eat moderate-sized portions and control calories.
Researchers have not established a direct link between obesity and incidence of prostate cancer. However, obesity might affect levels of hormones related to prostate cancer risk.
Strategies for preventing obesity include:
- Following guidelines for a healthy diet
- Meeting with your doctor to develop a plan for physical activity
- Doing some form of aerobic exercise for 30 minutes or more daily
Certain drugs, vitamins and minerals may reduce your risk of prostate cancer, a strategy known as chemoprevention. Current research does not support the routine use of any drug or nutritional supplement to prevent prostate cancer. Yet several chemical agents show potential benefits.
Proscar (finasteride), traditionally prescribed to treat prostate enlargement, or benign prostatic hyperplasia (BPH), reduced overall rates of prostate cancer by 25 percent in the 18,000-man Prostate Cancer Prevention Trial (PCPT). Men who took finasteride, however, were more likely to experience impotence, loss of sexual desire and breast enlargement than those who took a placebo. In addition, the men who did develop prostate cancer while taking Proscar were more likely to have aggressive forms of the disease. The reasons for these results are unknown.
Another BPH drug, duasteride, also seems to have properties that prevent prostate cancer. A large, international study is now underway to further test this finding.
Finally, nonsteroidal anti-inflammatory drugs (NSAIDS) might prevent prostate cancer. These drugs include ibuprofen (Advil, Motrin, others) and naproxen (Aleve). NSAIDS inhibit an enzyme called COX-2, which is found in prostate cancer cells. More studies are needed to confirm whether NSAID use actually results in lower rates of prostate cancer or reduced deaths from the disease.
Soybeans and other legumes contain phytoestrogens, which are plant-based chemicals that behave like the hormone estrogen in the human body. These chemicals might help to prevent prostate cancer. In fact, one possible explanation for lower rates of prostate cancer in Asian men is that they eat more soy protein.
Researchers are not sure how phytoestrogens could produce this effect. Phytoestrogens may decrease levels of androgens, male hormones that stimulate the growth of prostate cancer. Or, phytoestrogens might simply balance out androgen effects.
Tomatoes and related products, such as tomato sauce and ketchup, might offer protection in a different way — by providing lycopene. This vitamin-like substance acts as an antioxidant, lowering cancer risk by preventing DNA damage in the nuclei of cells. Go for the richest sources of lycopene — processed tomatoes, pink grapefruit and watermelon rather than supplemental lycopene in tablet form.
Selenium and vitamin E
Years of nutrition research have suggested that daily doses of the mineral selenium, vitamin E or both may help to prevent prostate cancer. The Selenium and Vitamin E Cancer Prevention Trial (SELECT), launched in 2001, is following up on these observations.
By its projected endpoint in 2013, SELECT will have data on prostate cancer diagnosis and treatment from over 32,000 men. These men are taking selenium, vitamin E, a combination of both, or a placebo. By studying such a large number of people over so many years, researchers will gain detailed evidence about the preventive effects of these two substances.
A word of caution: Taking herbal medicines or nutritional supplements without medical guidance poses some risks — particularly if you combine such products with over-the-counter or prescription medications. Before using any drug, herb or supplement, talk to your doctor.
The reasons for interest in preventing prostate cancer are clear. Prostate cancer is the second most common cause of cancer death in men, exceeded only by lung cancer.
Even so, prostate cancer affects far more men than it eventually kills. According to the National Cancer Institute, about one-fifth of men in the United States will be diagnosed with prostate cancer during their lifetime. Yet only 3 percent of American men will die of the disease.
Why does the number of prostate cancer diagnoses exceed the number of deaths by such a large ratio? One answer is that prostate cancer progresses more slowly than many other types of cancer. Many men live with it for years. Some survive disease-free after treatment. And others refrain from treatment while closely monitoring the cancer's progression — an approach known as "watchful waiting."
To keep your risks in perspective, stay in regular contact with your doctor about your prostate health. Ask about prevention strategies that make the most sense for you, given your current health and medical history.
An annual prostate checkup can't reduce your risk of cancer, as perhaps a healthy diet and exercise can. But having regular checkups is crucial to staying healthy. If prostate cancer does develop, a digital rectal exam (DRE) and a prostate-specific antigen (PSA) test may discover the problem in its earliest stages. This is the time when treatment can be most effective.