Vitamin E and evening primrose oil for management of cyclical mastalgia: A randomized pilot study

OBJECTIVE: To evaluate the effectiveness of vitamin E, evening primrose oil (EPO), and the combination of vitamin E and EPO for pain control in women with cyclical mastalgia. PROCEDURE: A double-blind, randomized, placebo-controlled trial was conducted at two U.S. academic medical centers. Eighty-five women with premenstrual cyclical breast discomfort were enrolled. Participants were randomly assigned to one of four six-month oral treatments: vitamin E (1,200 IU/day), EPO (3,000 mg/day), vitamin E (1,200 IU/day) plus EPO (3,000 mg/day), or double placebo. The primary outcome measure was change in breast pain, measured by the modified McGill Pain Questionnaire at enrollment and at six months. RESULTS: Forty-one patients completed the study. Intent-to-treat analysis (pretesting and post testing) showed a difference in worst-pain improvement with the treatments EPO (p=0.005), vitamin E (p=0.04), and EPO plus vitamin E (p=0.05), but no difference with placebo (p=0.93). Results from two-sample t-test showed a nonsignificant decrease in cyclical mastalgia individually for the three treatment groups compared with the placebo group (EPO, p=0.18; vitamin E, p=0.10; and EPO plus vitamin E, p=0.16). The data were also analyzed with the separation test by Aickin, which showed a trend toward a reduction of cyclical mastalgia with vitamin E and EPO individually and in combination. CONCLUSION: Daily doses of 1,200 IU vitamin E, 3,000 mg EPO, or vitamin E and EPO in combination at these same dosages taken for six months may decrease the severity of cyclical mastalgia.