Gamma-linolenic Acid: Function & Diseases

Gamma-linolenic acid represents a triple unsaturated fatty acid that is a precursor of important hormones in the body. It is an omega-6 fatty acid. It is synthesized in the body from linoleic acid or absorbed through important vegetable oils.

What is gamma-linolenic acid?

Gamma-linolenic acid is an important triple unsaturated fatty acid that belongs to the omega-6 fatty acids. It is the starting material for the biochemical synthesis of dihomolinolenic acid and arachidonic acid. Dihomolinolenic acid forms series 1 eicosanoids, while arachidonic acid is the starting material for series 2 eicosanoids. Eicosanoids are tissue hormones to which the prostaglandins also belong. While series 1 eicosanoids have an anti-inflammatory effect, series 2 eicosanoids virtually promote inflammation. The designation omega-6 fatty acids indicates how far the last double bond is from the terminal carbon atom of the chain. In the Greek alphabet, the letter omega is the last letter. Transferred to the fatty acid molecule, the last carbon atom of the fatty acid molecule is called the omega carbon atom. The number 6 denotes the distance of the last double bond from the direction of the carboxyl group from the omega carbon atom. In gamma-linolenic acid, the first double bond after the carboxyl group starts at the gamma carbon atom, i.e., the third carbon atom. Gamma-linolenic acid is produced in the body from the essential omega-6 fatty acid linoleic acid. Linoleic acid and gamma-linolenic acid are found in vegetable oils.

Function, effects, and roles

Unsaturated fatty acids, including gamma-linolenic acid, have great biological importance in the construction of cell membranes and the synthesis of important tissue hormones. As omega-6 fatty acids, they are mainly found in vegetable oils as triglyceride esters. In the human organism, the fatty acids are incorporated back into the cell membranes as phospholipids. The more unsaturated fatty acids they contain, the more supple and flexible the membranes become. Important substance transports and defenses against foreign invaders are improved. The cell remains viable for longer. A second important task is the synthesis of a large number of active substances and hormones that regulate certain cell functions. The hormones include the prostaglandins, thromboxanes and leukotrienes. The prostaglandins perform many functions. They are responsible for immune reactions, evoke defense reactions in the form of inflammation, and at the same time have an anti-inflammatory effect. They thus cover a multitude of functions that appear outwardly contradictory, but are equally necessary. For a healthy body, therefore, an optimal ratio of the various active substances and thus of their starting materials is of great importance. Thus, although series 1 and 2 eicosanoids are equally necessary. However, series 1 eicosanoids are considered good because of their anti-inflammatory effects and series 2 eicosanoids are considered bad because of their support of inflammatory and sometimes painful defense reactions. Overall, gamma-linolenic acid strengthens the immune system, regulates blood pressure and heart function, accelerates wound healing, is effective against eczema, strengthens the liver and kidneys, increases fertility, strengthens learning ability, concentration and nerves. Furthermore, both anticoagulant and procoagulant hormones are synthesized from the prostaglandin product class. Leukotrienes, which are also produced, mediate inflammatory reactions in the context of defense reactions against pathogens, as well as in allergic reactions.

Formation, occurrence, properties, and optimal levels

The human body is dependent on unsaturated fatty acids. Gamma-linolenic acid, which is synthesized from linoleic acid, plays a key role. However, in addition to linoleic acid, the body also needs alpha-linolenic acid as an omega-3 fatty acid and oleic acid as an omega-9 fatty acid. All three unsaturated fatty acids are desaturated (incorporation of an additional double bond) by the same enzyme. This is delta-6 desaturase, which only functions with the help of the cofactors vitamin B6, biotin, calcium, magnesium and zinc. Thus, gamma-linolenic acid is formed from linoleic acid, which in turn is further converted into dihomogammalinolenic acid and arachidonic acid. Docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) are synthesized from alpha-linolenic acid. Gamma-linolenic acid and linoleic acid are found in various vegetable oils.Borage oil with 20 percent, evening primrose oil with 10 percent and hemp oil with 3 percent are particularly rich in these fatty acids.

Diseases and disorders

From gamma-linolenic acid, dihomo-gamma-linolenic acid is synthesized via the enzyme delta-6-desaturase, and from this, in turn, arachidonic acid is synthesized in small amounts. These substances in turn give rise to the good series 1 eicosanoids and the bad series 2 eicosanoids. A third series, series 3 eicosanoids, also belong to the anti-inflammatory prostaglandins and are thus antagonists of series 2 eicosanoids. When there is a ratio of omega-6 fatty acids to omega-3 fatty acids in foods in favor of omega-6 fatty acids, the development of inflammatory processes is more likely because more arachidonic acid can be formed. Allergic reactions, asthma and painful inflammatory processes are more likely to occur. Therefore, more omega-3 fatty acids should be included in the diet. These are contained especially in fish oils. The ratio of omega-6 fatty acids to omega-3 fatty acids should be 5 to 1. It is much higher today. However, this is true if the enzyme delta-6-desaturase is functioning optimally. If this enzyme fails due to a mutation, for example, only series 2 eicosanoids are formed, with constant inflammation, asthmatic complaints, rheumatism and much more. This is because arachidonic acid is also absorbed through food and does not necessarily have to be produced in the body. In this case, there are no anti-inflammatory counterparts. In the long term, constant inflammatory processes lead to severe organ damage, arteriosclerosis, cardiovascular disease, severe gastrointestinal inflammation with malabsorption symptoms and other symptoms. However, the function of delta-6-desaturase is also limited if important cofactors such as biotin, vitamin B6, calcium, magnesium or zinc are missing. Furthermore, the activity of the enzyme is also inhibited in obesity, diabetes mellitus, alcohol and nicotine consumption, viral infections, liver disease, stress or physical inactivity. Therefore, these conditions are severe risk factors for health.