essential fatty acid

fatty acid /fat·ty ac·id/ (fat´e) any straight chain monocarboxylic acid, especially those naturally occurring in fats.

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essential fatty acid  any fatty acid that cannot be synthesized by the body and must be obtained from dietary sources, e.g., linoleic acid and linolenic acid.

free fatty acids  (FFA) nonesterified f. a's.

monounsaturated fatty acids  unsaturated fatty acids containing a single double bond, occurring predominantly as oleic acid, in peanut, olive, and canola oils.

nonesterified fatty acids  (NEFA) the fraction of plasma fatty acids not in the form of glycerol esters.

ω-3 fatty acids , omega-3 fatty acids unsaturated fatty acids in which the double bond nearest the methyl terminus is at the third carbon from the end; present in marine animal fats and some vegetable oils and shown to affect leukotriene, prostaglandin, lipoprotein, and lipid levels and composition.

ω-6 fatty acids , omega-6 fatty acids unsaturated fatty acids in which the double bond nearest the methyl terminus is at the sixth carbon from the end, present predominantly in vegetable oils.

polyunsaturated fatty acids  (PUFA) unsaturated fatty acids containing two or more double bonds, occurring predominantly as linoleic, linolenic, and arachidonic acids, in vegetable and seed oils.

saturated fatty acids  those without double bonds, occurring predominantly in animal fats and tropical oils or produced by hydrogenation of unsaturated fatty acids.

trans– fatty acids  stereoisomers of the naturally occurring cis– fatty acids, found in margarines and shortenings as artifacts after hydrogenation.

unsaturated fatty acids  those containing one or more double bonds, predominantly in most plant-derived fats.

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essential fatty acid (EFA),

a polyunsaturated acid, such as linoleic, alpha-linolenic, and arachidonic acids, essential in the diet for proper growth, maintenance, and functioning of the body. EFAs are prostaglandin precursors that play important roles in metabolism. They are also necessary for the normal functioning of the reproductive and endocrine systems and the breaking up of cholesterol deposits on arterial walls. The best dietary sources are natural vegetable oils, such as soy and corn oils; margarines blended with vegetable oils; wheat germ; edible seeds, such as pumpkin, sesame, and sunflower; and fish oils, especially cod liver and other fish body oil. Although rare, a deficiency of EFAs causes changes in cell structure and enzyme function, resulting in decreased growth and other disorders. Symptoms include brittle and lusterless hair, nail problems, dandruff, allergic conditions, and dermatoses, especially eczema in infants. Also excessive amounts may reduce the level of vitamin E in tissues and cause other metabolic disturbances.