Eating Right, Exercise May Help Prostate Cancer Patients Reduce Risk of Aggressive Tumors
June 29, 2013 — Researchers at UCLA's Jonsson Comprehensive Cancer Center (JCCC) have published the first study on adherence to eight World Cancer Research Fund (WCRF) lifestyle recommendations and aggressive prostate cancer that shows a significantly decreased risk of highly aggressive prostate cancer associated with closer adherence to the recommendations. The recommendations provided desirable ranges of body mass index, physical activity, foods of low caloric density (under 125 kilocalories per 100 grams of food), fruits and non-starchy vegetables, salt, legumes and unrefined grains, and red meat consumption.
Led by Lenore Arab, PhD, JCCC member and professor in the departments of medicine and biological chemistry, the researchers examined associations between adherence to WCRF recommendations and risk of highly aggressive prostate cancer among subjects enrolled in the North Carolina-Louisiana Prostate Cancer Project. Study subjects were 2212 African American or Caucasian American men 40 to 70 years old with newly diagnosed prostate cancer. WCRF recommendations are intended to decrease overall risk of cancer, and are recommended for cancer survivors. The study was published online ahead of print in the journal Nutrition and Cancer.
Adherence to fewer than four of the eight WCRF recommendations predicted a 38% increased risk of aggressive tumors compared with adherence to four or more recommendations. That finding was statistically significant and similar among black and white men, despite a baseline higher risk of highly aggressive tumors among black men. In particular, eating less than 500 grams of red meat per week or less than 125 total kilocalories per 100 grams of food per day were statistically significantly protective against highly aggressive tumors for all subjects in the study.
Each point in a patient's total adherence score corresponded to a 13% reduction in risk of aggressive cancer. A total adherence score of less than 4 predicted an increased risk of aggressive tumors in African American and Caucasian patients.
"Most men are at risk of prostate cancer, but it is the level of aggressiveness of disease that is most clinically relevant," Arab says, "These findings suggest that even men with prostate cancer can take control of their disease and moderate its aggressiveness through diet and lifestyle choices."
Measurement of prostate cancer aggressiveness was based on Gleason grading system scores, blood levels of prostate-specific antigen, and TNM malignant tumor classification.
Adherence to WCRF recommendations was based on point scores and odds ratios estimated. These findings assume that patients' reports reflect their long-term dietary habits, which is supported by research that indicates that diet is relatively stable in adulthood.