In a previous epidemiological survey among Danish women, menstrual pain prevalence (dysmenorrhea) was found to be inversely associated with dietary fishoil content (N-3 fatty acid) and B-12-vitamin intake. The findings supported a hypothesis that menstrual cramps, which are prostaglandin mediated, can be influenced by dietary fatty acids and suggested a potential use of fish oil supplements as treatment of or prevention of dysmenorrhea. The aim of the study was to test this hypothesis. The study was designed as a double blind, placebo controlled trial, in which 78 dysmenorrheic young women were given 5 capsules a day of either fishoil, fishoil with B-12, sealoil, or placebo consisting of "average" Danish fat, during a 3-4 months intervention period covering at least 3 menstrual periods. The compliance was followed by blood and gluteal fat lipid profiles. After about three months of treatment there was significant reduction in the number of reported menstrual symptoms and interference with daily activities in all three groups receiving marine oils, p<0.05. There were highly significant reductions in reported pain grade ( categorical and visual analog scales) by fishoil with B-12, and borderline significant effects of fishoil alone and of sealoil. Fishoil with B-12 was consistently better than the other treatments and at a higher level of significance p<0.01 and its symptom reducing effects lasted for at least three months of washout period. The results of this clinically controlled trial thus confirm the previous epidemiological findings and suggest that dietary supplements with fish- or sealoil, enriched with, or in combination with B-12 vitamin can substantially reduce menstrual discomfort. (C) 2000 Elsevier Science Inc.
