What are Omega-3 fatty acids?

11 November 2017

ALA, DHA, EPA… what does this all mean? There are many different kinds of omega-3 fatty acids and although they all play an important role in good nutrition, they are not all the same. Omega-3 fatty acids are a group of essential polyunsaturated fatty acids that help your body function at its best. These fats are deemed essential because our bodies cannot produce them ourselves, meaning they much be consumed through diet and supplements. These are the types of fats that are referred to as “healthy fats” because they work to prevent heart disease, fight inflammation, aid in nerve function and mental cognition, and provide many other health benefits. There are three main types of omega-3 fatty acids; alpha-linolenic acid (ALA), eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA). Each of these has a different function in our bodies. [1]


ALA is the omega-3 fatty acid that is the most prominent component of our diet, coming from from foods such as nuts, seeds, flaxseed oil, soybeans, tofu, pumpkin seeds, and canola oil. The body converts the short-chain polyunsaturated fatty acid ALA into the long-chain polyunsaturated fatty acids EPA and DHA to put it to use. However, research suggest that only a small amount of DHA can be synthesized in the body from this process. EPA and DHA that come from animal-based food sources, such as fish and supplements do not need to be converted, going straight to work for your body!


EPA is another primary omega-3, which is naturally found in cold-water fatty fish. It plays a role in supporting the body’s normal inflammatory responses. In addition to this, it has been linked to supporting a healthy heart, triglyceride levels, and blood pressure. [2, 3] There is also research investigating EPA in relation to mood and depression. [2, 3]


DHA is another omega-3 naturally found in cold-water fish. DHA is the most readily absorbed form of omega-3s, being a key component of all cell membranes. While our bodies do make some DHA on their own from ALA, we cannot make enough at a significant rate. The conversion rate from ALA to DHA in our bodies is often less than 1 per cent.[1]

DHA is essential in supporting the healthy growth and development of the brain and eyes, while also maintaining healthy function throughout life. Adequate DHA is especially necessary during the early years of life, as babies and young children need it to properly develop their brains, eyes, and nervous system during this period of rapid growth. As we age, DHA intake remains crucial to maintaining healthy brain function, as it comprises the majority of fatty acids in our brain cell membranes. Click here to read more about why DHA is important for babies and young children.

  1. [1] “Where to Find EPA DHA.” Omega 3s, Always a Good Idea, https://alwaysomega3s.com/what/explore-good-sources. [2] Hjalmarsdottir, Freydis. “The 3 Most Important Types of Omega-3 Fatty Acids.” Healthline, Healthline Media, 27 May 2019, https://www.healthline.com/nutrition/3-types-of-omega-3#section8. [3] Sears, Barry. “What Are the Real Differences Between EPA and DHA?” Psychology Today, Sussex Publishers, 1 Apr. 2012, https://www.psychologytoday.com/ca/blog/in-the-zone/201204/what-are-the-real-differences-between-epa-and-dha.
Tags: brain, DHA, oily fish, omega-3, omega-3 fatty acids, recommendations, seafood


Brigitte Zeitlin

Brigitte Zeitlin, MPH, RD is a registered dietitian-nutritionist and owner of BZ Nutrition, a private nutrition counseling practice. She has been featured in Us Weekly, Women’s Health, SELF, and Well+Good. Become a client and work with Brigitte by visiting bznutritionny.com.

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