A polyunsaturated fatty acid called gamma-linolenic acid can be made in your body from linoleic acid -- an essential fatty acid in food fats, including oils. After its synthesis, gamma-linolenic acid is converted into other compounds that have antiinflammatory properties. Insufficient conversion of linoleic acid into gamma-linolenic acid may create an apparent essential fatty acid deficiency that may contribute to inflammatory disorders. Most people make adequate gamma-linolenic acid and do not need to take a supplement. Talk to your doctor before taking this or any supplement.
Gamma-Linolenic Acid Nutrition
Gamma-linolenic acid is not an essential fatty acid, meaning you are not reliant on your diet to supply this substance. An enzyme called delta-6-desaturase converts the essential omega-6 fatty acid called linoleic acid into gamma-linolenic acid in your body. After production from linoleic acid, gamma-linolenic acid is converted into antiinflammatory compounds, including prostaglandin E1.
Delta-6-desaturase activity may be inefficient or defective in some people, and a relative gamma-linolenic acid deficiency may contribute to hypersensitive skin conditions and diabetes-associated nerve damage. People with delta-6-desaturase insufficiency may benefit from gamma-linolenic acid-rich dietary supplements, including evening primrose oil or black currant seed oil.
Atopic eczema, also known as atopic dermatitis, is a common inherited inflammatory skin disorder. Affected people have dry, red, scaly and itchy skin that is hypersensitive to irritants. The condition is associated with high levels of linoleic acid and low levels of gamma-linolenic acid circulating in the blood, suggesting impaired conversion of linoleic acid into gamma-linolenic acid.
Dietary supplements with sources of gamma-linolenic acid have been found to improve symptoms of atopic dermatitis in some studies. For example, a study published in the December 2011 issue of the "Journal of Oleo Science" found that consuming test foods containing 200 mg of gamma-linolenic acid daily for 4 weeks relieved symptoms in people with mild dermatitis.
The process of converting dietary linoleic acid into gamma-linolenic acid is often inadequate in people with diabetes. The resulting gamma-linolenic acid deficiency may contribute to long-term damage to the retina in the eyes, the kidneys, blood vessels and nerves -- a condition called diabetic neuropathy. The effect of 480 mg of gamma-linolenic acid per day over a 1-year period was assessed in a clinical study of 111 people with mild diabetic neuropathy. People who received the gamma-linolenic acid supplement had significantly better nerve and muscle function at the end of study compared to people who did not, according to the report appearing in the January 1993 issue of "Diabetes Care."
Rheumatoid arthritis is a health condition that causes pain, swelling, inflammation and loss of function in affected joints. Although evidence is inconclusive, gamma-linolenic acid supplements may benefit people with rheumatoid arthritis, according to a review published in the February 16, 2011 issue of the "Cochrane Database of Systematic Reviews." For example, in 56 people with active rheumatoid arthritis, a supplement containing 2.8 g of purified gamma-linolenic acid per day for 1 year significantly relieved arthritis symptoms, according to a clinical study published in the November 1996 issue of "Arthritis and Rheumatism."
Although gamma-linolenic acid supplements are usually well tolerated, side effects may occur, as with any medication or supplement. Digestive system upset has been reported, especially with prolonged usage or high doses. Gamma-linolenic acid supplements may also reduce the effectiveness of antiseizure medication.
Be sure to inform each of your health care providers about all medications and supplements you are taking to make sure there are no adverse interactions.
- The American Journal of Clinical Nutrition: Fatty Acid Metabolism in Health and Disease: The Role of Delta-6-Desaturase
- The Journal of Nutrition: Importance of Dietary Gamma-Linolenic Acid in Human Health and Nutrition
- The American Journal of Clinical Nutrition: Essential Fatty Acid Metabolism and Its Modification in Atopic Eczema
- Journal of Oleo Science: Dietary Supplementation of Gamma-Linolenic Acid Improves Skin Parameters in Subjects With Dry Skin and Mild Atopic Dermatitis
- Diabetic Medicine: The Use of Gamma Linolenic Acid in the Prevention and Treatment of Diabetic Neuropathy
- Diabetes Care: Treatment of Diabetic Neuropathy With Gamma-Linolenic Acid
- Beth Israel Deaconess Medical Center: Gamma-Linolenic Acid (GLA)
- Cochrane Database of Systematic Reviews: Herbal Therapy for Treating Rheumatoid Arthritis
- Arthritis and Rheumatism: Gamma-Linolenic Acid Treatment of Rheumatoid Arthritis. A Randomized, Placebo-Controlled Trial
- Integrative Medicine, Third Edition; David Rakel, M.D., et al.; 2012