International Omega-3 Learning and Education Consortium for Health and Medicine

First and foremost, omega-3 fatty acids must be consumed in our daily diets because the body cannot make them from other types of fat in the diet. Omega-3 fatty acids are polyunsaturated fatty acids, (PUFA) with three or more double bonds. They are found in foods such as walnuts, canola oil, marine cold-water fish and fish oils (see Food products for more examples).

Within the omega-3 family, there are differences in food sources and those from marine sources have more health benefits. Alpha-linolenic acid (ALA) is the essential omega-3 fatty acid and is present in walnuts, flax oil and canola oil. ALA can (to a very limited extent) be converted to the more active and beneficial forms of omega-3 fatty acids: eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). However, this conversion of ALA to EPA and DHA is poor. To get EPA and DHA, it is best to eat foods such as marine cold-water fish (i.e. salmon, mackerel, or tuna [fresh or canned in water]) and foods fortified with EPA or DHA (refer to Food products). For more information about the structures and how the body uses omega-3 fatty acids please see omega-3 fatty acid structures.

Recommendations for ALA intakes in the United States were last made in 2005 by the Institute of Medicine. Other countries have similar recommendations (please see Recommendations for omega-3 fatty acids). It is recommended that an adequate intake is 1.6 g/day for men and 1.1 g/day for women.