Low-Fat Fish Oil Diet for Prostate Cancer Prevention

Studies on patterns of how many men get prostate cancer in other countries show that environment contributes to the high incidence of prostate cancer in the United States. Epidemiology studies suggest that this influence may be reduced by the diet of men at risk of getting prostate cancer. Although the exact nature of the effects of diet are not completely known, the amount of fat eaten appears to affect the number of men who get prostate cancer. The type of fat also seems to matter. Eating more of a type of fat called omega-3 polyunsaturated fat is associated with decreased prostate cancer risk. Omega-3 fat comes from fish and is quite different from the type of fat from animals and vegetables (omega-6 fat). Because the exact mechanism of this reduction in prostate cancer risk is not known, no blood test indications, called markers, have been discovered that would show the effect working. Study doctors designed this study to try to find markers in the blood tests of men who have prostate cancer, and to find out if a diet supplemented with omega-3 type fat from fish oil helps reduce those markers, hence indicating that it helps reduce the cancer in these men. These men will be compared to men with prostate cancer whose diets do not contain the fish-oil fat. The men chosen will have prostate cancer and be scheduled for operations to have their prostate glands removed. They will be chosen randomly to be given the fish-oil diet or a regular Western diet for comparison for 4 to 8 weeks. Their blood will be checked at the beginning of the diet. After the 4-to-8-week period, they will have their operations. Their blood will be checked again and a sample of their removed prostate will be examined to tell if the diet had any effect on the cancer and its markers.