Linolenic acid is an 18-carbon polyunsaturated fatty acid with three double bonds. The chemical formula for this molecule is CH₃(CH₂CH=CH)₃CH₂(CH₂)₆COOH. The isomer called α(alpha)-linolenic acid (n-3), an Omega-3 fatty acid, is essential for all mammals. A particularly rich food source is flaxseed.

(alpha)-linolenic acid

(alpha)-linolenic acid has been linked with:

• reduced cardiovascular risk through reduced arrhymthmias
• reduced carotid arteriosclerosis

Derivatives of this fatty acid include

• eicosapentaenoic acid, EPA
• docosahexaenoic acid, DHA

(!!This input below may be inaccurate!!) It also seem to be negatively linked to:

• prostate cancer
• macular degeneration

In fact a mutant of flax, Linola , has been developed in Australia which is low in this fatty acid compared to natural flax.

Another isomer of linolenic acid is γ(gamma)-linolenic acid (n-6), an Omega-6 fatty acid which is the product of desaturation of Linoleic acid. This fatty acid is rare in food, though it is found in borage, blackcurrant, and evening primrose. It is sometimes taken as an oil supplement because its elongation product, di-homo-γ-linolenic acid, is an important constituent of cell membrane phospholipids in its role as precursor to the series-1 eicosonoids.

The names α-linolenic acid (n-3) and γ-linolenic acid (n-6) are trivial names for all-cis-octadeca-9,12,15-trienoic acid and all-cis-octadeca-6,9,12-trienoic acid, (18:3 n-6), respectively.^{Pollution Prevention: Chapter 2 - Properties and Fates of Environmental Contaminants, instructional slides to accompany Pollution Prevention:Fundamentals and Practice, by Paul L. Bishop (ISBN 0073661473). Retrieved 2005-03-07.}

1. ^{⇧ Joint Committee of International Union of Nutritoinal Sciences and IUPAC Commission on Food (2001). Lexicon of Lipid Nutrition. Pure and Applied Chemistry 73(4), 685-744. Retrieved 2005-03-07. also used here as a general reference for sources of the substances and in the existence of Linola}