ABSTRACT
Although animals cannot synthesize α-linolenic acid, they can metabolize it by further desaturation and elongation; desaturation occurs at carbon atoms below carbon number nine (counting from the carboxyl carbon) and mainly occurs in the liver. α-Linolenic acid can be converted to stearidonic acid (18:4ω-3) by delta-6 desaturase and then stearidonic acid can be elongated to eicosatetraenoic acid (20:4ω-3) (Figure 8.2). This fatty acid can be further desaturated by delta-5 desaturase to yield eicosapentaenoic acid (20:5ω-3; known as EPA) (Figure 8.2). Conversion of α-linolenic acid
8.1 Structure, Naming, and Biosynthesis of ω-3 Fatty Acids..................................................... 197 8.2 Dietary Sources and Typical Intakes of ω-3 Fatty Acids ..................................................... 199
8.2.1 α-Linolenic Acid from Plant Sources ....................................................................... 199 8.2.2 EPA, DPA, and DHA from Seafood ......................................................................... 199 8.2.3 Fish Oils ....................................................................................................................200
