A total of 161 men diagnosed with prostate cancer and scheduled at least 21 days before prostatectomy were randomized into 4 groups – control (usual diet), flaxseed-supplemented (30gm/day), low-fat diet (<20% of energy from dietary fat), or flaxseed-supplemented plus low fat. Dietary questionnaires, serum and urine levels of relevant compounds and prostatectomy tissue were assessed. The primary study endpoint was proliferation index (by Ki-67 staining using the antibody MIB-1) in the prostatectomy tissue. Men were on treatment for an average of 30 days. Tumor proliferation was significantly lower in the flaxseed-supplemented arm (proliferation index = 1.66), compared to 3.23 for controls, 2.56 for low-fat diet, and 1.50 for the combined flaxseed with low-fat diet. No differences were noted between groups for apoptosis (programmed cell death) and most serologic (identification of antibodies in the blood serum) endpoints. Men in the low-fat diet group had significant reductions in body mass index and total and low-density lipoprotein cholesterol (p= 0.048). Findings suggest that flaxseed may be protective for prostate cancer and provides evidence for low-fat diets to manage cholesterol. (14)
