n ?3 fatty acids (popularly referred to as ??3 fatty acids or omega-3 fatty acids ) are a family of unsaturated fatty acids that have in common a final carbon?carbon double bond in the n ?3 position; that is, the third bond from the methyl end of the fatty acid. more

n ?3 fatty acids (popularly referred to as ??3 fatty acids or omega-3 fatty acids ) are a family of unsaturated fatty acids that have in common a final carbon?carbon double bond in the n ?3 position; that is, the third bond from the methyl end of the fatty acid.

Important nutritionally-essential n ?3 fatty acids are: ?-linolenic acid (ALA), eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA), all of which are polyunsaturated. The human body cannot synthesize n ?3 fatty acids de novo , but it can form 20- and 22-carbon unsaturated n ?3 fatty acids from the eighteen-carbon n ?3 fatty acid, ?-linolenic acid. These conversions occur competitively with n ?6 fatty acids, which are essential closely related chemical analogues that are derived from linoleic acid. Both the n ?3 ?-linolenic acid and n ?6 linoleic acid are essential nutrients which must be obtained from food. Synthesis of the longer n ?3 fatty acids from linolenic acid within the body is competitively slowed by the n ?6 analogues. Thus accumulation of long-chain n ?3 fatty acids in tissues is more effective when they are obtained directly from food or when competing amounts of n ?6 analogs do not greatly exceed the amounts of n ?3. less