Interventions with flaxseed had higher EPA in erythrocytes and prostate tissue and decreased n-6:n-3 ratio in prostate tissue (p < 0.05); reduced tumor proliferation rate (Ki67) in interventions with flaxseed (p < 0.05); no difference between groups for apoptosis (TUNEL), serum SHBG, free androgen index, IGF-1, IGFBP-3, and CRP. The gene discussed is IGF1; the disease is neoplasm.