Many people are familiar with the term “omega-3.” And many people also know that good sources of omega-3 are fish and flaxseeds. But did you know that these two sources contain different types of omega-3? Flaxseed contains the omega-3 called alpha-linolenic acid (ALA) and fish contains two different types of omega-3: docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA).
ALA actually converts into EPA, which then can convert into DHA (and vice versa). These conversions, however, occur on a very limited basis. ALA only converts to EPA at a rate of between 8 and 20 percent, and only converts to DHA (by way of EPA) at a rate of between 0.5 and 9 percent. Many people take omega-3 in the ALA form, like flaxseed oil, thinking that they are getting all the benefits of omega-3s, but they’re not getting the whole story. Certainly ALA is a beneficial omega-3. But most of the benefits of ALA are thought to be due to its eventual conversion into EPA and DHA—especially when it comes to heart health.
A recent study published in the American Journal of Clinical Nutrition highlights this point. Data based on 3,277 healthy Danish adults found that a higher intake of ALA over 23 years was not associated with a reduction in risk of ischemic heart disease—the most common form of heart disease, and the most common cause of death in the U.S. But intake of other long-chain omega-3s—like EPA and DHA—was associated with a reduced risk.
The researchers found that intakes ranging from 0.45 to 11.2 grams per day were associated with a 38 percent reduced risk of ischemic heart disease for women. This is a large range, certainly, and higher doses of EPA and DHA should only be taken under the consult of a doctor. But the American Heart Association does recommend that people consume the equivalent of 500 mg per day of EPA and DHA (not ALA) if they are healthy and want to maintain heart health; 1 gram per day if they have coronary heart disease; and 2 to 4 grams per day if they have high triglycerides.
If you are taking an omega-3 supplement, take a look at the label and see how much EPA and DHA you are getting. This is what you should be looking for in a high-quality omega-3.