Linoleic acid

The term essential means that these fatty acids must be supplied in the diet because the body needs them but cannot synthesize them.

Linoleic acid is a major fatty acid in plant lipids. In animals it is derived mainly from dietary plant oils. It is the precursor for the synthesis of long chain omega-6 fatty acids— gamma-linolenic acid (GLA), dihomo-gamma linolenic acid (DGLA) and arachidonic acid (AA).

Humans lack the enzymes to introduce double bonds at carbon atoms beyond the C-9 in the fatty acid chain.LA and ALA obtained from foods furnished by the diet are the starting point for the synthesis of a variety of other unsaturated fatty acids.

The abundance of linoleic acid and resulting high ω-6 to ω-3 PUFA ratio in current Western diets significantly impedes the conversion efficiency of ALA.
Linolenic acid