There are three types of essential fatty acids (EFAs) called Omega-3, Omega-6 and Omega-9 according to the number of carbon atoms in their molecular chain. The longer 6 and 9 chain EFAs are found in nuts, vegetable oils and other foods, and can be obtained in adequate amounts from the diet. Omega-3, the most important EFA group, is often deficient in our diets and must be supplemented.
There are two main sources of Omega-3 – vegetable and marine. The richest vegetable source of Omega-3 is flax oil. Unfortunately the Omega-3 in flax oil, alpha-linolenic acid (ALA), is an inactive form which requires conversion in the body to the active forms eicosapentaenoic acid (EPA) and docosahexanoic acid (DHA). Research shows that only a small percentage of ALA is converted into the active forms. A better source of Omega-3s is fish oil which contains DHA and EPA. Coldwater ocean fishes such as sardines, anchovies and salmon; squid; and krill, a small shrimp-like crustacean, are the best sources.
EPA is important for heart and blood vessel health and for regulation of inflammation. It is converted in our bodies to eicosanoids (discussed in my October 18, 2010 column) which reduce pain and inflammation in conditions such as arthritis or IBS. EPA is also important for regulation of mood and has been found beneficial in the treatment of depression and anxiety.
DHA, sometimes called the “Brain EFA”, forms an essential component of the central nervous system and the eye. A deficiency of DHA can result in poor development of brain and eyes, memory problems, learning disorders such as ADHD, and vision problems such as glaucoma. DHA also plays a role in cardiovascular health. DHA is especially important during pregnancy and breastfeeding when the infant brain is developing.
This article is intended for educational purposes only; for medical advice consult your licensed health practitioner.