|
Health Options
Alan Titchenal |
Good diet may lower
prostate cancer riskThe statistics are sobering: One in six men will develop prostate cancer. Some are at even greater risk: Among men who have a father or a brother with prostate cancer, one in three are destined to fall ill. A man with three close relatives who've had prostate cancer is almost certain to get the disease, with only a 3 percent chance of avoiding it.
Question: What causes prostate cancer?
Answer: Although the causes of prostate cancer are not fully understood, various things are associated with increased risk. In addition to family history, just being over age 50 increases risk. The average age of diagnosis is 70. Also, racial background is a factor, with African-American men at greater risk than whites and Asians having the least risk.
Diet appears to play a role. Some evidence suggests that a diet high in fat, particularly animal fat, may increase risk and a diet high in fruits and vegetables may decrease risk.
Q: How can prostate cancer be prevented?
A: There is no sure-fire way, but there are things that are likely to reduce one's risk substantially.
The American Cancer Society recommends limiting consumption of high-fat red meats and eating at least five servings of fruits and vegetables each day. Including plenty of whole-grain foods along with beans and other legumes also is recommended. These habits may help reduce the risk of other cancers, as well.
Foods rich in compounds called lycopenes, such as tomatoes and tomato products, pink grapefruit and watermelon are considered to be protective due to their antioxidant properties.
Q: Can nutritional supplements decrease the risk of prostate cancer?
A: Some (but not all) studies have indicated that supplements of vitamin E and selenium reduce the risk.
Zinc also may be important. The concentration of zinc is higher in the prostate gland than in any other body tissue. Although adequate amounts of zinc in the diet may be protective, excessively high intake from dietary supplements may actually increase the risk. A recent study reported in the Journal of the National Cancer Institute found that men with a daily supplemental zinc intake of more than 100 mg per day (about 10 times the RDA) had more than double the risk of men who took no supplements containing zinc.
Good dietary sources of zinc include oysters, lean red meats, crab meat, dark meat of turkey and chicken, milk, yogurt and cheese. Some beans, grains and vegetables contain a fair amount of zinc, but the zinc is not as readily absorbed as it is from animal sources. Also, something in red wine enhances zinc absorption -- it's not the alcohol.
Although eating a good diet can decrease the risk of prostate cancer, it is no guarantee of avoidance. Consequently, early detection and proper treatment are essential. Two techniques are used for diagnosis. One is based on a simple blood test for the level of prostate-specific antigen. The PSA test, combined with a physical examination, is considered the most comprehensive method of detection.
See the Columnists section for some past articles.
Alan Titchenal, Ph.D., C.N.S. and Joannie Dobbs, Ph.D., C.N.S. are nutritionists in the Department of Human Nutrition, Food and Animal Sciences, College of Tropical Agriculture and Human Resources, UH-Manoa. Dr. Dobbs also works with the University Health Services and prepares the nutritional analyses marked with an asterisk in this section.
