Omega-6 Fatty Acids
Omega 6 fatty acids are one of two groups considered to be essential; the other being the Omega 3 fatty acid class. Both of these fatty acids are considered essential because the body has no way of manufacturing them, as the builiding blocks needed for creation are absent in human physiology. As well, the human body can not break down other substances in body for Omega 3 and Omega 6 fatty acid conversion. Fatty acids are an essential component in human nutrition. They are the building blocks for all cells and are a necessity in the production of cell signaling molecules known as prostaglandins.
The majority of fatty acids found in the body, can be made from precursors via cellular reactions that either break down the starting molecule or add to it. The essential omega 6 fatty acids cannot be made from precursors in the body, and include; linoleic acid (LA) and gamma-linolenic acid (GLA). The sources for these omega 6 fatty acids are listed below.
Omega 6 fatty acids are considered a natural anti-inflammatory because they favor the production of prostaglandins that are anti-inflammatory, as opposed to prostaglandins that are pro-inflammatory. These same pathways that produce prostaglandins also make leukotrienes, substances that are involved in allergic reactions and asthma. Thromboxanes, substances that regulate the stickiness of platelets, are also derived from the the aforementioned production pathway. Omega 6 fatty acids help in decreasing the harmful effects these substances can have on our bodies when they are produced in excess.
The high intake of animal fats high in arachadonic acid, another fatty acid that causes the production of pro-inflammatory molecules in our diet, creates an imbalance in the system. In no case would it be beneficial to eliminate the production of inflammatory cell signals, because they do provide a service to the body when needed. The goal of supplementation with Omega 6 fatty acids is to provide a healthy balance between the good and bad prostaglandins, leukotrienes, and thromboxanes, in order to avoid disease such as arthritis, asthma, and atherosclerosis.
Sources of linoleic acid include; safflower oil, sunflower oil, soybean oil, and canola oil. The most abundant gamma-linolenic acid sources: evening primrose oil, borage oil, and black currant seed oil.
Omega 6 fatty acids are beneficial for inflammatory skin conditions such as eczema. Supplementation in children resulted in a decrease in redness, scratching, and anti-histamine use.  There were no side effects associated with long-term use. One theory proposes that individuals who suffer from atopic disease such as eczema, have a deficiency in the enzyme that drives the production of GLA. Supplementation with GLA has greatly improved the clinical succession of individuals with eczema. 
Omega 6 fatty acids have been used effectively in the treatment of rheumatoid arthritis. GLA has been shown to improve symptoms of RA by decreasing the production of inflammatory mediators involved in the disease process.  Omega 6 fatty acids are also suggested to decrease the overall severity of the disease; including signs and symptoms common during active ‘flare-ups.’ 
Omega 6 fatty acids may be a beneficial treatment option for sicca syndrome, or dry eyes. Both GLA and LA have been shown to decrease the many adverse symptoms associated with this conditon, including improvements in eye moisture, reductions regarding the inflammation of the eye. 
Omega 6 fatty acids may also be employed in alternative therapies for patients with multiple sclerosis. In study, linoleic acid has been shown to reduce the severity of disease and to increase the duration of time between relapse and onset. Studies suggest that such fatty acids may be effective for all stages of multiple sclerosis.
Omega 6 fatty acids are helpful for individuals who suffer from diabetic neuropathy. Omega 6’s have been shown to increase nerve function, hot and cold sensation, improve deep tendon reflexes, and increase muscle strength. [7-8] Omega 6 fatty acids may decrease high blood pressure and are considered effective at decreasing total cholesterol. [9, 10]
Finally, Omega 6 fatty acids may be a beneficial adjunctive treatment for women with breast cancer. In one particular study, GLA was shown to increase the effects of tamoxifen.  Althought its mechanism of action is not fully understood, it is thought that GLA may interact with specific steroid hormone receptors on cancer cells.
Doses of Omega 6 fatty acids can range from 2 to 15 grams per day. The most common dosages used in research studies are 3 to 6 grams per day. Different conditions will respond to varying dosages.
There are no side effects or toxicity associated with the supplementation of Omega 6 fatty acids. Extremely large doses for long periods of time may cause weight gain due to the increase in caloric intake.
Because Omega 6 fatty acids have the potential to decrease clotting, individuals who are taking medication to decrease the formation of blot clots, such as warfarin, should inform their doctor before beginning treatment with Omega 6 fatty acids.
High doses of essential fatty acids should be taken with Vitamin E to avoid lipid peroxidation and rancidity.
1. Fiocchi A, Sala M, Signoroni P, Banderali G, Agostini C, Riva E. The efficacy and safety of gamma linolenic acid in the treatment of infantile atopic dermatitis. J Int Med Res. 1994 Jan-Feb; 22(1): 24-32.
2. Maiken MS et al. Reduced levels of prostaglandin precursors in the blood of atopic patients: defective delta 6 desaturase function as a biochemical basis for atopy. Prostaglandins Leukot Med. 1982 Dec; 9(6): 615-628.
3. Ziboh VA et al. Suppression of LTB4 generation by ex-vivo neutrophils isolated from asthma patients on dietary supplementation with gamma linolenic acid containing borage oil: possible implications in asthma. Clin Dev Immunol. 2004 Mar; 11(1): 13-21.
4. Zurier RB et al. GLA treatment of rheumatoid arthritis. Arthritis Rheum. 1996 Nov; 39(11): 1808-1817.
5. Barabino S et al. Systemic linoleic acid and gamma linolenic acid therapy in dry eye syndrome with an inflammatory component. Cornea. 2003 Mar; 22(2): 97-101.
6. Dworkin RH, Bates D, Millar JH, Paty DW. Linoleic acid and multiple sclerosis: a reanalysis of three double blind trials. Neurology. 1984 Nov; 34(1): 1441-1445.
7. Horrobin DF. Essential fatty acids in the management of impaired nerve function in diabetes. Diabetes. 1997 Sep; 46(Suppl 2): S90-93.
8. Keen H et al. Treatment of diabetic neuropathy with gamma linolenic acid. The GLA Multicenter Trial Group. Diabetes Care. 1993 Jan; 16(1): 8-15.
9. Deferne JL, Leeds AR. Resting blood pressure and cardiovascular reactivity to mental arithmetic in mild hypertensive men supplemented with black currant seed oil. J Hum Hypertens. 1996 Aug; 10(8): 531-537.
10. Rasicis G, Kestin M, Nestel PJ. Linoleic acid lowers LDL cholesterol with out proportionate displacement of saturated fatty acid. Eur J Clin Nutr. 1991 Jun; 45(6): 315-320.
11. Kenny FS et al. Gamma linolenic acid with tamoxifen as a primary therapy in breast cancer. Int J Cancer. 2000 Mar 1; 85(5): 643-648.