What are the types of omega-3 fatty acids?

Janis Jibrin, MS, RD
Nutrition & Dietetics
There are three main types of omega-3 fatty acids:

Alpha-linolenic acid (ALA) is the omega-3 fatty acid that's found in plants. ALA is critical to our survival; it's one of the two "essential" fatty acids that the body cannot make, so we must get it from foods (linoleic is the other essential fatty acid).

Sources: Have one of the following every day: flaxseeds or flaxseed oil, canola oil, walnuts, and foods enriched with omega-3s, such as these products sporting the Best Life Seal of Approval: Barilla PLUS pasta, Flatout Flatbread, Hellman's Canola Cholesterol Free Mayonnaise, Silk DHA Omega-3 & Calcium Soymilk (contains both ALA and DHA), Smart Balance Buttery Spread, Smart Balance Peanut Butter.

Eicosapentaenoic acid (EPA) and docohexaenoic acid (DHA) are the omega-3s found primarily in fish; there are also small amounts in meat from grass-fed animals. These seem to have more potent and direct benefits to the heart, brain, and joints than ALA and are what make up most omega-3 supplements.
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Anthony L. Komaroff, MD
Internal Medicine
There are three main types to keep track of: eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA), and alpha-linolenic acid (ALA). EPA and DHA are found mainly in fish, so they're sometimes called marine omega-3s. ALA is found in plant-based foods, such as flaxseed, walnuts, and canola and soybean oils.

So far, the evidence for EPA and DHA having health benefits is more extensive than for ALA. Studies have shown that EPA and DHA offer some measure of protection against heart attacks and strokes. EPA and DHA also have anti-inflammatory effects that may be useful in preventing or treating conditions like rheumatoid arthritis and inflammatory bowel disease. Some well-designed studies of ALA are under way, but right now there just aren't enough data to be confident about ALA having the same effects as EPA and DHA. And there's reason for doubting whether it does. The body converts ALA to EPA and then to DHA, but that happens only in small amounts. If you're aiming to increase your omega-3 intake to accomplish all the things that omega-3s are thought to do, increasing the amount of fish you eat is probably the best way to go. That said, flaxseed and the other ALA-rich oils may still be a healthful choice, if you are using them to replace trans or saturated fat.

The American Heart Association recommends that adults eat two servings of omega-3-rich fish (salmon, for example) per week, which works out to about 400 to 500 milligrams (mg) of EPA and DHA per day. People with heart disease are advised to double that, so their daily intake is 1,000 mg, or a full gram. Taking fish oil capsules is often the most practical way to get that amount of omega-3s. If you choose to take fish oil capsules, note that the amount of EPA and DHA provided is often only about a third of that listed on the front of the bottle. Check the Nutrition Facts label on the back for the actual amount.
Dr. Mehmet Oz, MD
Cardiology (Cardiovascular Disease)
Omega-3 fatty acids are the superstar fats that boost your brain, protect your heart and arteries, fight wrinkles, lubricate your joints, and more. There are three types of omega-3 fatty acids:
  • Alpha-linelenic acid (ALA), found in walnuts, flaxseeds, and olive oil
  • Docosahexaenoic acid (DHA), found primarily in fish oil
  • Eicosapentaenoic acid (EPA), also found in fish oil

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Important: This content reflects information from various individuals and organizations and may offer alternative or opposing points of view. It should not be used for medical advice, diagnosis or treatment. As always, you should consult with your healthcare provider about your specific health needs.