Description | Alpha-linolenic acid (ALA) is a polyunsaturated fatty acid (PUFA). It is a member of the group of essential fatty acids called omega-3 fatty acids. Alpha-linolenic acid, in particular, is not synthesized by mammals and therefore is an essential dietary requirement for all mammals. Certain nuts (English walnuts) and vegetable oils (canola, soybean, flaxseed/linseed, olive) are particularly rich in alpha-linolenic acid (ALA). Omega-3 fatty acids get their name based on the location of one of their first double bond. In all omega-3 fatty acids, the first double bond is located between the third and fourth carbon atom counting from the methyl end of the fatty acid (n-3). Although humans and other mammals can synthesize saturated and some monounsaturated fatty acids from carbon groups in carbohydrates and proteins, they lack the enzymes necessary to insert a cis double bond at the n-6 or the n-3 position of a fatty acid. Omega-3 fatty acids like a-linolenic acid are important structural components of cell membranes. When incorporated into phospholipids, they affect cell membrane properties such as fluidity, flexibility, permeability and the activity of membrane bound enzymes. Omega-3 fatty acids can modulate the expression of a number of genes, including those involved with fatty acid metabolism and inflammation. Alpha linolenic acid and other omega 3 fatty acids may regulate gene expression by interacting with specific transcription factors, including peroxisome proliferator activated receptors (PPARs) and liver X receptors (LXRs). |