AARHUS, DENMARK. Menstrual pain (menstrual cramps, dysmenorrhea) is believed to be associated with an elevated level of PG2 prostaglandins. PG2 prostaglandins are synthesized from the omega-6 fatty acid, arachidonic acid and are known to be pro-inflammatory. The formation of PG2 prostaglandins competes with the formation of PG3 prostaglandins from the omega-3 fatty acid, eicosapentaenoic acid (EPA), the main component of fish oil. PG3 prostaglandins are anti-inflammatory.
Danish researchers have completed a study to determine if the ratio between omega-3 and omega-6 fatty acids in the diet is associated with menstrual pain. Their study involved 181 healthy Danish women between the ages of 20 and 45 years who did not use oral contraceptives and who were not pregnant. The women completed 4-day food frequency questionnaires and recorded their menstrual symptoms, particularly the extent of pain. The researchers noted a strong association between increased pain and a low intake of omega-3 fatty acids from fish or fish oils, between increased pain and a low intake of vitamin B12 (also present in fatty fish), and between increased pain and a low ratio of omega-3 to omega-6 fatty acids in the diet. They conclude that a higher intake of fish oils correlated with milder menstrual symptoms.
Deutch, B. Menstrual pain in Danish women correlated with low n-3 polyunsaturated fatty acid intake. European Journal of Clinical Nutrition, Vol. 49, 1995, pp. 508-16