Evening primrose oil and fish oil for severe chronic mastalgia: A randomized, double-blind, controlled trial

OBJECTIVE: The purpose of this study was to evaluate the effect of evening primrose oil and fish oil on breast pain in premenopausal women with severe chronic mastalgia, in a randomized double-blind factorial clinical trial. STUDY DESIGN: One hundred twenty women were placed randomly into four groups: (1) fish oil and control oil, (2) evening primrose oil and control oil, (3) fish and evening primrose oils, or (4) both control oils during 6 months. Corn oil and corn oil with wheat germ oil were used as control oils. The change in the percentage of days with breast pain after 6 months of treatment was analyzed on an intention-to-treat basis. RESULTS: The decrease in days with pain was 12.3% for evening primrose oil and 13.8% for its control oil (P = .73); the decrease in days with pain was 15.5% for fish oil and 10.6% for its control oil (P = .28). CONCLUSION: All groups showed a decrease in pain. Neither evening primrose oil nor fish oil offered clear benefit over control oils in the treatment of mastalgia.