Gamma Linolenic Acid: Sources and Functions

Abstract

Gamma‐linolenic acid (GLA, cis 6, cis 9, cis 12‐octadecatrienoic acid) is a conditionally essential fatty acid of the n‐6 family. It is produced in the mammalian body from enzymatic desaturation of linoleic acid, an essential fatty acid that must be supplied by the diet. It is widely distributed in plant kingdom in trace amounts, and is not present in major commercial vegetable seed oils. It is present in seeds of many species belonging to families Aceraceae, Boraginaceae, Cannabinaceae, Liliaceae, Onagraceae, Ranunculaceae, Saxifragaceae, and Scrophulariaceae. A very limited number of plant sources have been commercialized in last 30 years as a source of GLA, mainly in the health food industry and to a limited extent in pharmaceutical, pet food, and cosmetic industries. These include oils of borage, black currant, evening primrose, and recently hemp. The total market for GLA‐containing oils is about $60–$70 million per year. Research on GLA in last three decades has focused on the physiological and pharmacological effects, including its effects on second messenger system in the body. On the production side, research focus is on identification of new sources and yield optimization. This article reviews the current state of knowledge about sources, and nutritional and health benefits of GLA and attempts to identify areas for future research that will help develop markets for GLA.

Rare fatty acids and lipids in plant oilseeds: occurrence and bioactivity

“…Oenothera biennis L., evening primrose), Boraginaceae (Borago officinalis L., borage), Grossulariaceae (Ribes nigrum L. black currant), Malvaceae (Durio graveolens Becc. ), Cannabaceae (Cannabis sativa L., hemp) produce substantial amounts (7-20%) of this fatty acid as a constituent of their seed oils (PlantFAdb 2016;Guil-Guerrero et al 2001;Alonso-Esteban et al 2020;Kapoor and Nair 2020). In addition to higher plant species, γlinolenic acid has been also detected in animals, protozoa, fungi, algae and mosses.…”

“…γ-Linolenic acid is classified as a "conditionally essential fatty acid", because it becomes essential to humans in some specific health conditions. Several scientific studies have demonstrated that a high intake of ω-6 fatty acids such as γ-linolenic acid is beneficial to human health since its endogenous formation in the human body is low or impaired in some pathological conditions including diabetes, atopic dermatitis, cardiovascular disease, rheumatoid arthritis and cancer (Fan and Chapkin 1998;Belch and Hill 2000;Kapoor and Huang 2006;Kawamura et al 2011;Simon et al 2014;Kapoor and Nair 2020). Reduction of the synthesis of γ-linolenic acid also limits the physiological production of dihomo-γlinolenic and arachidonic acids with the consequent decrease in the formation of eicosanoids (prostaglandins, prostanoids and prostacyclins), important cell signalling molecules involved in several physiological and pathological processes.…”

The protective effects of Gamma-linolenic acid against indomethacin-induced gastric ulcer in rats

“…Few plant sources have been used for commercial GLA production, mainly in health food, pharmaceutical, pet food and cosmetic industries. These sources include oils from borage, evening primrose, black currant and, more recently, hemp (10) . The GLA treatment effectively inhibits the growth of gastric cancer cells in hypoxia.…”