α-Linolenic acid (ALA) is an essential omega 3 fatty acid and organic compound found in seeds, nuts, and many common vegetable oils. α-Linolenic acid is a carboxylic acid with an 18-carbon chain and three cis double bonds. The first double bond is located at the third carbon from the methyl end of the fatty acid chain, known as the n end. α-Linolenic acid, an n−3 fatty acid, is a member of the group of essential fatty acids (EFAs), so called because they cannot be produced within the body and must be acquired through diet. Most seeds and seed oils are much richer in an n−6 fatty acid, linoleic acid. Exceptions include flaxseed (must be ground for proper nutrient absorption) and walnuts. Linoleic acid is also an EFA, but it, and the other n−6 fatty acids, compete with n−3s for positions in cell membranes and have very different effects on human health.
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