Department of Food Science and Human Nutrition
Extension
Colorado State University
Fort Collins, CO 80523-1571
Healthy Heart Beats
January-March 2008
Vol 30, Issue 1
Dining a la Health
Omega-3 Claims May Be Confusing
If you're a conscientious shopper who reads labels you may be among those who feel confused about the different kinds of omega-3 fatty acids: docosahexaenoic acid (DHA), eicosapentaenoic acid (EPA), and apha-linolenic acid (ALA). Omega-3 fatty acids are important polyunsaturated fatty acid (PUFAs) and they play a crucial role in brain function, reduce inflammation and help prevent risk factors associated with heart disease and cancer. The only dietary essential omega-3 fatty acid is ALA. Dietary DHA and EPA are beneficial but not essential since they can be made from ALA. Some groups think it is advisable to consume 400-600 mg per day of EPA + DHA. The Institute of Medicine (IOM) Dietary Reference Intake bases their Adequate Intake (AI) on ALA intakes. While they recognize that dietary DHA and EPA can meet some of the AI, their recommendation is based on dietary ALA. The AI for ALA is 1.1 to 1.6 g/day for women and men, respectively.
DHA and EPA, long chain omega-3 fats, can be found in cold water fish, such as salmon, tuna, and halibut. The American Heart Association recommends eating fish (particularly fatty fish) at least twice a week. ALA is found in flaxseeds, flaxseed oil, canola (rapeseed) oil, soybeans, soybean oil, pumpkin seeds, pumpkin seed oil, walnuts, and walnut oil.
If a product contains EPA, DHA or ALA, the label can claim that it's a source of "omega-3." EPA and DHA are 20- and 22 carbon fatty acids. ALA, the shorter long-chain (18 carbons) omega-3 fatty acid, is a precursor to both EPA and DHA, and has to be converted by the body into EPA and DHA. However, the conversion is inefficient.
Many consumers may be misled into thinking they are getting adequate omega-3's by including these manufactured foods in their diet with the omega-3 health claim on the label. Many labels do not indicate how much omega-3 is present, nor do they indicate the form of omega-3. Most of the time it's safe to assume that any omega-3 claim refers to ALA. Unless the label specifically lists EPA and DHA (which should be listed in the ingredient label as fish or fish oil) or DHA (derived from algae), strive to include at least one rich source of omega-3 fatty acids in your diet every day. Rather than depending on manufactured foods with omega-3 claims consider including a serving of fatty fish (such as salmon), a tablespoon of canola or soybean oil in salad dressing or in cooking, or a handful of walnuts or ground flaxseed mixed into your breakfast cereal.
All food sources of omega-3 fats are not created equal. Here are the amounts of DHA and EPA, the omega-3 fats backed by the most promising studies, in some foods:
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