EPA and DHA decreased risk of many chronic diseases.

No type of fat has been getting more recent publicity than omega-3s, and you’re very likely to have seen TV ads or heard radio infomercials about this unique type of fat. However, much of the omega-3 publicity you’ve heard has probably been focused on dietary supplements rather than food. In this profile, we’ll provide you with a fresh look at omega-3s from the perspective of food and the best ways to balance your meal plan for strong omega-3 support.

Omega-3s belong to a broader group of fats called polyunsaturated fats. Sometimes you’ll hear this group called “poly” fats. The specific members of this group are called polyunsaturated fatty acids, or PUFAs. What’s most important about PUFAs—including omega-3s—is one special aspect of their chemical structure. They contain what are called “double bonds”—special connections that make them more flexible and interactive as fatty acids; they also make them more delicate and susceptible to damage. All PUFAs—including all omega-3s—contain at least two double bonds. But the position of the double bonds in omega-3s is unique and simply not found in other fats.

Some omega-3s are simpler than others. The simplest is called alpha-linolenic acid, or ALA. Like most vitamins, ALA is especially important in our diet because our bodies cannot make it from scratch. Either we consume it, or we don’t have enough. Fortunately for us, many commonly eaten plant and animal foods contain ALA.

For other omega-3s, this all-or-nothing scenario is not the case. Under the right circumstances, our bodies can usually take ALA and transform it into other omega-3s. These other omega-3s are more complicated than ALA and contain more double bonds. The best studied are EPA (eicosapentaenoic acid) and DHA (docosahexaenoic acid). EPA has five double bonds and DHA has six. In a large number of research studies, there are clear health benefits provided by EPA and DHA that are not provided by ALA. These health benefits involve support of many body systems and decreased risk of many chronic diseases.

So without question, our bodies need ALA, EPA, and DHA to stay healthy, and we need to consume ALA-containing foods no matter what because our bodies lack the ability to make ALA. But what about EPA and DHA? Are we absolutely required to eat foods containing EPA and DHA?

The answer to that question is particularly important since it can affect our entire approach to eating. If we only need to eat ALA-containing foods—and can trust our bodies to make all of the EPA and DHA that we need—we become free to choose whatever type of diet we would like, including a strict vegan diet that contains no animal foods whatsoever (including no milk, no cheese, and no eggs). That’s because a wide variety of plant foods contain small-to-moderate amounts of ALA. However, if we need to obtain EPA and DHA directly from food, we become much more restricted in our food choices. For example, if we are trying to implement a strict vegan diet with no animal foods whatsoever and want to obtain DHA from our diet, our choices would most likely be limited to sea plants (which can contain DHA) or some fermented foods (like fermented soy foods) which had been allowed to ferment with the help of specific fungi that were capable of producing DHA.