What Is Omega 6 And What Foods Can It Be Found In?

With all of the furor over America's "obesity epidemic" and the outcry over high-fat foods, it is sometimes easy to forget that you need some fat in your diet to stay healthy. The traditional view that fats are simply energy storage molecules is outdated. Fatty acids play important roles in hormone production, cell membrane integrity, immune function, inflammation and a myriad of other physiologic activities. However, the type of fat you eat makes a significant impact on your health.

Fatty Acids

Fatty acids, which are one of several forms of lipids in your body, are simply chains of carbon atoms that are hooked together with either single or double bonds. A carbon atom possesses four electrons that it can share with other atoms. The sharing of one electron with another atom creates a single bond, while the sharing of two electrons forms a double bond. A fatty acid is said to be "saturated" if all of its carbon links are joined by single bonds. Conversely, an "unsaturated" fatty acid contains at least one double bond, as in a "monounsaturated" fatty acid, or multiple double bonds, as in a "polyunsaturated" fatty acid.

Omega Numbering

Chemists who study fatty acids have developed their own nomenclature, and, like any scientific language, it can be confusing to everyone but the chemists. The two ends of fatty acid chains differ from one another, with the "acid" end bearing two oxygen atoms. By convention, scientists number the carbon links in a fatty acid chain beginning at the end opposite the oxygen atoms. If the fatty acid contains any double bonds, it is assigned an "omega" number that coincides with the first double bond in the chain. Hence, if the first double bond occurs right after the third carbon link, the fatty acid is called an omega-3 fatty acid. Likewise, if the first double bond occurs after the sixth carbon, it is an omega-6 fatty acid, and so on.

Omega-6 and Metabolism

The three principal omega-6 fatty acids that are involved in human metabolism are linoleic acid, or LA, arachidonic acid, or AA, and gamma-linolenic acid, or GLA. LA is an essential fatty acid, meaning your body cannot synthesize it, so it must be acquired from your diet. AA and GLA are manufactured in your cells, using LA for the raw material. Because AA is eventually converted to inflammatory molecules called prostaglandins, some health experts recommend that Americans decrease their consumption of LA. However, a 2010 review in "Current Opinion in Clinical Nutrition and Metabolic Care" points out that the dietary ratio of omega-6 to omega-3 fatty acids is probably more important than your total intake. While opinions vary, an omega-6 to omega-3 ratio of around 4 to 1 is a good target.

Dietary Sources

According to Dr. Elson Haas, author of "Staying Healthy with Nutrition," the typical U.S. diet is replete with omega-6 fatty acids. In fact, the average American consumes 20 to 30 times more omega-6 fatty acids than omega-3s. Most plant oils, including corn, peanut, poppy seed, safflower, canola, sesame, soy, sunflower and walnut oils, contain ample supplies of LA. Egg yolks are another good source. GLA can be obtained from borage, evening primrose, hempseed and black currant oils, as well as from human milk and some fungi.