ABSTRACT
Polyunsaturated fatty acids (PUFA) can be differentiated into two groups according to the position of the double bounds in the fatty acid (FA) chain. Because mammalian cells cannot introduce double bonds at position 3 or 6 from the terminal methyl group, they are unable to produce α-linolenic acid (ALA; C18:3, n-3) and linoleic acid (LA; C18:2, n-6) (Figure 25.1). These FAs are essential for human organisms.
