Arachidonic acid
Arachidonic acid (AA) is a 20-carbon ω-6 conditionally essential fatty acid. It sits at the head of the "arachidonic acid cascade" – more than 20 different signalling paths that control a wide array of bodily functions, but especially those functions involving inflammation, cell growth and the central nervous system. Most AA in the human body derives from dietary linoleic acid (another essential fatty acid, 18:2 ω-6), which is derived from nuts, seeds, vegetable oils and animal fats.