Omega-6 fatty acids are one of the healthy types of fat that protects against disease. While omega-6 fats are necessary to biological functioning, deficiencies are rare. The average American gets between 9 and 17 g per day of this type of fat from diet alone. Supplements of specific types of omega-6 fatty acids are available to treat specific conditions, but you should consult a doctor before taking any supplementary omega-6 fats.
PUFAs
Omega-6 fatty acids are a type of polyunsaturated fat, or PUSF. Polyunsaturated fats consist of a long chain of carbon atoms with more than one double bond somewhere along the chain. In omega-6 fatty acids, the first double bond is found immediately after the sixth carbon atom of the chain. Like omega-3 fatty acids, which have their first double bond after the third atom, the basic forms of omega-6 fats are considered essential fats. The body cannot insert a double bond after the third or sixth carbon atom, making it necessary to get these fats through diet.
Types
The main omega-6 fat in the diet is linoleic acid, or LA, which has 18 carbon atoms in its chain. Vegetable oils are a major source of LA. In the body, LA can be converted into gamma-linolenic acid, or GLA, and arachidonic acid, or AA. This conversion process involves adding another double bond and some additional carbons to the 18-carbon chain. Both GLA and AA have 20 carbon atoms and are considered long-chain omega-6 fats. Some specialty oils, such as primrose oil, borage oil and black currant seed oil, contain GLA as well.
Health Impact
In the body, omega-6 fats become part of the membrane of cells, regulate gene expression and act as chemical messengers. Most forms of free omega-6 fats cause inflammation in the body, a negative effect. However, GLA seems to be anti-inflammatory, according to the University of Maryland Medical Center. While research is inconclusive about the specific benefits of GLA, some people take supplements containing it to treat allergies, rheumatoid arthritis, eczema, high blood pressure and premenstrual symptoms. The American Heart Association recommends getting 5 to 10 percent of your total caloric intake from omega-6 fats, since this level of intake is linked to a reduction in cardiovascular disease.
Considerations
While omega-6 fatty acids are essential to human health, most people take in more than necessary. Also, the ratio of omega-6 to omega-3 fats should be a 1-to-1 ratio, but most Americans consume 14 to 25 times more omega-6s than omega-3s. Instead of significantly reducing omega-6 intake, however, you should reduce omega-6 intake only slightly and aim to get more omega-3 fats in the diet to bring the ratio closer to 1-to-1.
References
- University of Maryland Medical Center: Omega 6 fatty acids
- Linus Pauling Institute at Oregon State University: Essential Fatty Acids
- "Circulation": Omega-6 Fatty Acids and Risk for Cardiovascular Disease: A Science Advisory From the American Heart Association Nutrition Subcommittee of the Council on Nutrition, Physical Activity and Metabolism
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