Linolenic acid

Alpha linolenic acid (linolenic from lat. lini - linseed), or ALA for short, is a triple unsaturated, essential C18: 3 omega-3 acid (also known as omega-3 fatty acid ) that occurs in numerous vegetable oils. The term "alpha-linolenic acid" is often used synonymously with linolenic acid.
Gamma-linolenic acid, also known as gamolenic acid, has a slightly different chemical structure as a C18: 3 omega-6 acid (omega-6 fatty acid).
Linolenic acids are found in vegetable oils, such as the seed oil of Borago officinalis(borage), Cannabis sativa(hemp), linseed oil, walnut oil, rapeseed oil and soybean oil.
Linoleic acid, an omega-6 fatty acid similar in name to linolenic acid, has one less double bond than linolenic acid (see illustration).
Chemically bound linolenic acid is found as an ester in many triglycerides, which make up a large proportion of natural fats and oils.
The triglycerides of a whole range of naturally obtained vegetable oils are rich in linolenic acid residues.

Gamma-linolenic acid is used medicinally for the lubrication of topicals in atopic eczema. It is also used for age-related or drug-induced (e.g. through the use of retinoids) desiccation of the skin.
The use of gamma-linolenic acid in acne vulgaris requires further investigation.

1. Desbois AP et al. (2013) Antibacterial activity of long-chain polyunsaturated fatty acids against Propionibacterium acnes and Staphylococcus aureus. Mar Drugs 11:4544-4557.
2. Fujii M et al. (2013) Deficiency of n-6 polyunsaturated fatty acids is mainly responsible for atopic dermatitis-like pruritic skin inflammation in special diet-fed hairless mice. Exp Dermatol 22:272-277.
3. Kawamura A et al. (2011) Dietary supplementation of gamma-linolenic acid improves skin parameters in subjects with dry skin and mild atopic dermatitis. J Oleo Sci 60:597-607.
4. Lee HR et al. (2014) The efficacy and safety of gamma-linolenic acid for the treatment of acne vulgaris. Int J Dermatol 53:e199-e200.