Background
- Gamma linolenic acid (GLA) is a dietary omega-6 fatty acid found in many plant oil extracts. Commercial products are typically made from seed extracts from evening primrose (average oil content 7-14%), blackcurrant (15-20%), borage oil (20-27%) and fungal oil (25%). GLA is not found in high levels in the diet. It has been suggested that some individuals may not convert the omega-6 fatty acid linoleic acid to longer chain derivatives, such as GLA, efficiently. Thus, supplementation with GLA-containing oils, such as borage oil and evening primrose oil, is occasionally recommended to increase GLA levels in the body.
- GLA is available commonly as a dietary supplement and is sold over the counter in capsules or oil to treat a variety of conditions such as eczema, oral mucoceles (mucus polyps), hyperlipidemia (high cholesterol), depression, postpartum depression, chronic fatigue syndrome (CFS), psoriasis (chronic skin disease), muscle aches, and menopausal flushing.
- There is currently good evidence for GLA treatment in rheumatoid arthritis, acute respiratory distress syndrome, and diabetic neuropathy (nerve damage). Little or no effect has been found in treatment of atopic dermatitis, attention deficit hyperactivity disorder (ADHD), cancer prevention, menopausal flushing, systemic sclerosis, and hypertension (high blood pressure). GLA has also been used to help with the body's response to tamoxifen in breast cancer patients.
- Today, production and extraction of oil from evening primrose and borage is done by companies primarily in China, New Zealand, and England. Pharmaceutical licensing for GLA oil products has had only limited success worldwide.
References
Natural Standard developed the above evidence-based information based on a thorough systematic review of the available scientific articles. For comprehensive information about alternative and complementary therapies on the professional level, go to . Selected references are listed below.
- Bakshi A, Mukherjee D, Bakshi A, et al. Gamma-linolenic acid therapy of human gliomas. Nutrition 2003;19(4):305-309.
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View Abstract - Jamal GA, Carmichael H, Weir AI. Gamma-linolenic acid in diabetic neuropathy. Lancet 5-10-1986;1(8489):1098.
View Abstract - Middleton SJ, Naylor S, Woolner J, et al. A double-blind, randomized, placebo-controlled trial of essential fatty acid supplementation in the maintenance of remission of ulcerative colitis. Aliment Pharmacol Ther 2002;16(6):1131-1135.
View Abstract - Miles EA, Banerjee T, Dooper MM, et al. The influence of different combinations of gamma-linolenic acid, stearidonic acid and EPA on immune function in healthy young male subjects. Br J Nutr 2004;91(6):893-903.
View Abstract - Nelson JL, DeMichele SJ, Pacht ER, et al. Effect of enteral feeding with eicosapentaenoic acid, gamma-linolenic acid, and antioxidants on antioxidant status in patients with acute respiratory distress syndrome. JPEN J Parenter Enteral Nutr 2003;27(2):98-104.
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View Abstract - Remans PH, Sont JK, Wagenaar LW, et al. Nutrient supplementation with polyunsaturated fatty acids and micronutrients in rheumatoid arthritis: clinical and biochemical effects. Eur J Clin Nutr 2004;58(6):839-845.
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View Abstract - Takwale A, Tan E, Agarwal S, et al. Efficacy and tolerability of borage oil in adults and children with atopic eczema: randomised, double blind, placebo controlled, parallel group trial. BMJ 12-13-2003;327(7428):1385.
View Abstract - Usami M, Komurasaki T, Hanada A, et al. Effect of gamma-linolenic acid or docosahexaenoic acid on tight junction permeability in intestinal monolayer cells and their mechanism by protein kinase C activation and/or eicosanoid formation. Nutrition 2003;19(2):150-156.
View Abstract - van Gool CJ, Thijs C, Henquet CJ, et al. Gamma-linolenic acid supplementation for prophylaxis of atopic dermatitis--a randomized controlled trial in infants at high familial risk. Am J Clin Nutr 2003;77(4):943-951.
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