Arachidonic acid is a precursor for pro-inflammatory immune mediators, the 2-series prostaglandins, (e.g. prostaglandin E2), the leukocyte chemotactic metabolite, leukotriene B4, and platelet aggregating thromboxane A2. Thromboxane A2 has been implicated in the pathogenesis of coronary vascular disease, as it is not only a potent platelet aggregator, but also an effective vasoconstrictor.*

Although gamma-linolenic acid (18:3 omega-6) is a precursor of arachidonic acid, higher levels of dietary GLA actually compete with arachidonic acid, and may help downregulate the formation of excessive levels of proinflammatory 2-series prostaglandins and other immune mediators.*

Dietary supplementation with GLA has been suggested to be clinically effective in reducing the signs and symptoms of immune dysfunction. It has also been clinically associated with improvement of behavioral and physical problems, including premenstrual syndrome, learning disabilities, mental disturbance, weakness, poor coordination, and vision impairment.*

Recent studies suggest that dietary GLA can prevent the deficit on sciatic nerve conduction velocity (NCV) induced by poor glucose control. Although dietary GLA supplementation did not significantly influence the fatty acid composition of nerve membrane phospholipids, it was suggested that GLA’s effect was due to its modulation of levels of vasodilatory prostaglandins. Evening primrose oil is recognized as an excellent source of both GLA, as well as the essential linoleic acid. Therefore, regular supplementation with evening primrose oil may be beneficial for people consuming diets high in animal foods and low in unprocessed vegetable oils.*