KLK3 and cancer: Significant decreases in mean serum PSA concentrations by 17.5% and leukocyte 8OHdG by 21.3% after intervention was observed. Resected tissues from intervention group had 28.3% lower prostate 8OHdG compared with the control group (p < 0.03). Cancer cell 8OHdG staining of Gleason score‐matched resected prostate sections was reduced 36.4% in mean area (p < 0.018) and by 40.5% in mean nuclear density (p < 0.005) compared with the pre‐supplementation biopsy