Sources Of Omega-3 And Omega-6

Fatty acids are required for maintaining the normal structure and function of your cells. Your body cannot synthesize all of the fatty acids it needs, so you must obtain some of them from diet. For many years, scientists thought humans required only two dietary fatty acids: linoleic acid, or LA, and alpha-linolenic acid, or ALA. These nutrients were called essential fatty acids, or EFAs. Most experts now agree that you also need two other dietary fatty acids, eicosapentaenoic acid, or EPA, and docosahexaenoic acid, or DHA, for optimal health.

Conversion

Linoleic acid is an omega-6 fatty acid, while ALA, EPA and DHA are omega-3s. The "omega" designation simply refers to the basic chemical structure of these important molecules. Once inside your cells, both omega-3 and omega-6 fatty acids convert to a wide array of biological molecules, some of which bear little resemblance to their parent compounds. Nutritionists once believed that ALA was converted to EPA and DHA within your body, but studies have demonstrated that this conversion is inefficient, particularly in adult males.

Omega-3 Sources

Alpha-linolenic acid is primarily a plant-based nutrient. Flaxseed oil is a particularly rich dietary source of ALA. The seeds and oils from various other plants, such as pumpkin, chia, hemp, walnuts and fenugreek, also contain generous amounts of ALA. EPA and DHA are found in oily fish, krill and some marine algae. Supplements containing all of these fatty acids are available commercially.

Omega-6 Sources

Linoleic acid occurs in most plant oils, according to Elson Haas, M.D., author of "Staying Healthy with Nutrition." Sunflower, canola, safflower, sesame, poppy seed, corn, peanut, soy and walnut oils all contain LA. Rice bran, oat germ and wheat germ are additional sources. Two other omega-6 fatty acids, gamma-linolenic acid, or GLA, and arachidonic acid, or AA, are produced in your cells from linoleic acid, and they, too, have their own food sources. GLA occurs in borage, evening primrose and black currant oils, while AA is found in animal fats and egg yolks. Like omega-3 fatty acids, omega-6s are also available as supplements.

Considerations and Recommendations

The dietary proportions of omega-6 and omega-3 fatty acids hold important implications for your health. Haas states that the typical American diet supplies 10 to 20 times more omega-6 fatty acids than omega-3s, a ratio that contributes to many chronic inflammatory diseases, including heart disease, diabetes, arthritis and cancer. A 1999 National Institutes of Health Workshop suggested that your omega-6 intake should only be about 2.5 times your omega-3 intake. Based on a 2,000 calorie diet, your consumption of LA would not exceed 7 g; your intake of EPA plus DHA would be at least 650 mg; and you could consume approximately 2 g of ALA. While you can obtain essential fatty acids from your food, supplements are sometimes useful to achieve a healthier omega-6 to omega-3 ratio.