How to Avoid It
To understand prostate cancer, you should know the function of the prostate. The gland is a small, walnut-shaped body that surrounds the urethra, the tube that serves to transport both urine and semen out of the body, though not at the same time. The prostate’s function is to make and store a portion of the seminal fluid that nourishes and transports sperm upon ejaculation.
Unfortunately, the prostate is vulnerable to cancer. After skin cancer, prostate cancer is the most common cancer in the U.S., affecting one out of every six men. The majority of occurences are categorized as low-grade and are very slow growing. All victims with this form of the disease can expect to live at least 10 years beyond diagnosis and they usually die of something else. However, the high-grade form of the disease is much more aggressive and kills 60-70 percent of its victims within 10 years.
The Prostate Specific Antigen (PSA) blood test is most often used in conjunction with a Digital Rectal Exam (DRE) to assess risk of the disease. For the DRE, a physician wearing a rubber glove inserts his finger into the rectum and feels the prostate through the rectal wall to detect enlargement and irregularities. Both the PSA and DRE tests are generally administered to men 50 years and older during their routine physical exam, and to men as young as 40 who are considered at high risk.
A PSA reading of 4.0 or higher or a rapid increase in PSA between successive tests suggests the possibility of prostate cancer. However, the test is not foolproof and only 25-35% of men with a high PSA level actually have the disease. Also, some men with normal PSA levels may actually be afflicted. Positive PSA and DRE tests may be followed up by tissue sampling to look for the presence of cancer cells. Yet there is some risk of bleeding or infection. Treatment of the disease may also lead to loss of urinary control and erectile dysfunction, but improved techniques have reduced the incidence of these problems. A government committee recommended against testing men above 75 because the risks of treatment may exceed the benefits.
The following factors increase risk for the disease:
- Age: Risk rises dramatically with age. While there is only a slight chance of contracting the disease below age 40, the risk rises to 3% for ages 40-59, and 7% for ages 60-69. Two-thirds of all cases involve men over age 65.
- Race: Black men in the U.S. are over 60% more likely to develop the disease than Caucasian men, and almost two and a half times more likely to die from it. However, there is some evidence that the racial differences may be related to modifiable aspects of the environment and lifestyle.
- Family History: Men with a father, brother, or son having prostate cancer have twice the average risk of developing the disease. If two such relatives have the disease, a man’s risk is four times average. The risk is even greater if a man‘s relatives were diagnosed before 60 years of age.
- Heavy Drinking: Men who drink the alcohol equivalent of 4 shots of hard liquor 5 or more days per week are more than twice as likely as non-drinkers or moderate drinkers to develop the more lethal, high-grade form of the disease.
- Gene Mutations: The BRAC1 and BRAC2 gene mutations known for greatly increasing the risk of breast and ovarian cancers in women also affect male cancer risk. Men who have these gene mutations are not more likely than other men to develop prostate cancer, but when they contract the disease, it is much more likely to be of the aggressive, high-grade form. These gene mutations occur at a higher frequency among Jews of European descent than among other populations.
- Obesity: Obese men, characterized by a body mass index above 30 (e.g. 5‘10“, 210 lb) have twice the normal risk of getting the high-grade form of the disease. This may be because the PSA screening test is not as effective for obese men, leading to later diagnosis. It is therefore suggested that the cutoff PSA score suggestive of prostate cancer be 3.2-3.4 in obese men rather than the standard 4.0. Obese men have an additional risk: the disease is 60% more likely to come back after surgery among obese than normal-weight men.
- Agent Orange Exposure: During the war in Vietnam, the U.S. military sprayed more than 20 million gallons of an herbicide called Agent Orange on wide swaths of jungle to prevent enemy troops, equipment, and supplies from passing through the heavy foliage undetected. Men exposed to this herbicide have twice the average risk of developing prostate cancer. They are also more likely to get the more aggressive high-grade form of the disease, and it is more likely to spread to other parts of the body.
Some men worry unnecessarily that one or more of their personal characteristics increase their risk of prostate cancer. To dispel some of these concerns, we have compiled the following list of factors that some men erroneously believe increase their risk of the disease. THEY DO NOT ACTUALLY INCREASE THE RISK.
- Benign Prostate Hypertrophy: Many men experience an enlargement of the prostate that may make it difficult to urinate or increase the retention of urine in the bladder, necessitating more frequent bathroom visits. This condition does not at all increase the likelihood of developing prostate cancer.
- Prostate Infection: It is not unusual for men to develop a urinary tract infection that affects the prostate and can cause a burning sensation while urinating. This does not increase the likelihood of prostate cancer.
- Sexual Activity: Frequent sexual activity, in the form or intercourse or masturbation, does not increase the likelihood of developing prostate cancer. In fact, men who ejaculate more frequently appear somewhat less likely to develop the disease.
- Diabetes: Diabetics do not evidence an elevated risk for prostate cancer. In fact, men who have had diabetes for at least 6 years have about a 20-25% lower risk of developing prostate cancer than non-diabetic men. The reason is not well understood, but it may be a fortunate side-effect of drugs used to treat diabetes.
Reduce Your Risk
There are actions you can take to reduce your likelihood of contracting the disease. They include:
- Weight Control: If you have a normal level of body fat, avoid gaining weight. If you are overweight or obese, make an effort to lose weight. See our list of the most effective methods for losing weight.
- Exercise: In several studies physically active men were 10-30% less likely to develop the disease. Of men who were referred with medical reasons for prostate biopsies, those who exercised moderately (e.g. 3 or more hours per week of brisk walking) only had one-third the occurrence of actual prostate cancer as sedentary men. See our guidelines for a physical fitness program.
- Alcohol: Do not drink more than two servings of alcoholic beverages per day.
- Nutrition: The following changes in your diet can help reduce risk:
- Restrict your intake of saturated fats. These are most prevalent in fatty meats, full-fat dairy products, and tropical oils (palm and coconut).
- Limit your intake of red meat
- Eat plenty of fruits and vegetables, which reduce the risk of various forms of cancer.
- Eat cooked tomato products frequently. Men who eat tomato sauce or tomato paste at least four times per week have a 40% lower risk of developing the disease than men who hardly ever eat such foods.
- Be sure to get adequate vitamin D from either moderate sun exposure, fortified low-fat milk, or supplements.
- Drink green tea, which has been shown to kill prostate cancer cells in a test tube.
- NOTE: We can no longer recommend high consumption of fatty fish or fish oil to reduce the risk of prostate cancer. While the Mayo Clinic recommends fish oil for this purpose, a recent study indicated that high consumption of fatty fish and fish oil actually increased the risk of getting the aggressive, fast-growing form of the disease. It did not affect the risk of getting the much more common slow-growing form of the disease. Because heart disease is the number one killer of Americans, individuals may still decide to take fish oil for its beneficial effects on heart health.
Prostate Cancer > Disease Prevention