Alpha-linolenic Acid: Function & Diseases

Alpha-linolenic acid is the name given to a triple unsaturated fatty acid. It belongs to the group of omega-3 fatty acids.

What is alpha-linolenic acid?

Alpha-linolenic acid (ALA) or linolenic acid is an omega-3 fatty acid (n-3 fatty acid) that belongs to the triple-unsaturated fatty acids. These are long-chain fatty acids that have several double bonds. One bond is present on the third carbon atom. In addition to alpha-linolenic acid, docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) are among the most important representatives of omega-3 fatty acids. Alpha-linolenic acid is of essential importance. This means that the body cannot produce this vital substance itself. For this reason, it must be supplied with food. The chemical formula of linolenic acid is C18H30O2. At room temperature, it forms a colorless, oily liquid.

Function, effect and tasks

Alpha-linolenic acid gives rise to eicosapentaenoic acid in the human body, which is a precursor substance for the production of eicosanoids. These, in turn, are important for numerous significant bodily functions such as heart rate, blood pressure and musculature. They also prevent heart problems. The conversion of linolenic acid is carried out by an enzyme called delta-6-desaturase. Without this enzyme, there is a risk of skin diseases such as eczema. Linolenic acid also forms a component of cell membrane lipids. The double bonds in cis-configurations cause a kink within the molecular structure. The special structure causes elasticity in the cell membrane, which keeps it supple and mobile. This is important for an optimal supply of nutrients and the elimination of waste products. If the proportion of trans fatty acids or saturated fatty acids is too high, the cell membranes become rigid, which means that a good supply of nutrients and oxygen is no longer possible. For red blood cells (erythrocytes) in particular, it is extremely important that the membranes remain elastic. This ensures good oxygen supply to the neighboring tissues through optimal flowability into the smaller blood vessels. Therefore, a successful composition of the fatty acids of the cell membranes is of great importance for health. Alpha-linolenic acid plays an important role in inflammatory processes in the body and in combating them. In addition, omega-3 fatty acid is considered effective in the treatment of coronary heart disease. Thus, it has a direct influence on cholesterol metabolism. In addition, linolenic acid is involved in the regulation of blood pressure. Its anti-inflammatory effects come from reducing the inflammatory parameters cRP (c-reactive protein) and TNF (tumor necrosis factor). This in turn has a positive influence on inflammatory rheumatic diseases. According to recent scientific findings, alpha-linolenic acid also promotes bone metabolism and reduces bone loss in old age.

Formation, occurrence, properties, and optimal values

Alpha-linolenic acid cannot be formed by the human body. However, it can be produced synthetically by industry. Thereby the linseed oil forms the most important basic material for the production. The valuable linolenic acid is contained mainly in vegetable oils. These include linseed oil with a content of 50 percent, soybean oil, rapeseed oil, walnut oil, grape seed oil, chia oil, sunflower oil and hemp oil. In addition, the omega-3 fatty acid is found in abundance in green vegetables such as Brussels sprouts, spinach and kale. Other foods rich in linolenic acid include lard, flaxseed, wheat germ, wild berry fruits and specific wild herbs. Significant physical stress, such as competitive sports activities, usually increases the need for alpha-linolenic acid. Increased consumption of alpha-linolenic acid is recommended by the DGE (German Nutrition Society). The ideal ratio between alpha-linolenic acid and linoleic acid is 5:1. However, in industrialized countries, the ratio is usually 8:1. People need about one gram of alpha-linolenic acid every day. The DGE recommends a daily intake of 0.5 percent of the energy intake that occurs per day. This corresponds to a daily average energy intake of 2000 kcal per day. However, this amount is the absolute minimum. An intake of 1.5 grams of linolenic acid per day is therefore more sensible.Those suffering from chronic diseases should even double or triple their intake. To prevent heart attacks, some doctors recommend a weekly omega-3 fatty acid intake of 6 grams.

Diseases and disorders

Deficiency of alpha-linolenic acid occurs only in rare cases. Possible causes of deficiency symptoms are an artificial diet free of fats or permanent fat digestion disorders. A deficiency of linolenic acid is manifested by symptoms such as tremors, muscle weakness, visual problems, inadequate wound healing and disturbances in depth and surface sensitivity. In addition, those affected have limitations in their ability to learn. Babies and small children can also suffer from a deficiency of alpha-linolenic acid. This leads to visual disturbances, nerve problems and impaired growth. To prevent infants from suffering from a deficiency in the first place, since 1993 they have also been given omega-3 fatty acids in their special diet. However, an excess of alpha-linolenic acid is also considered unhealthy. For example, an excess supply of omega-3 fatty acids increases the tendency to bleed. It is also possible for the immune system and leukocytes (white blood cells) to lose function. For this reason, the proportion of linolenic acid should not exceed 3 percent energy. Caution is also advised when taking certain medications such as anticoagulants. Here, the increased intake of omega-3 fatty acids carries the risk of prolonged bleeding time or other negative effects on health. Furthermore, if medications are used regularly, the physician or pharmacist should be asked about possible interactions between drugs and alpha-linolenic acid. The therapeutic effect of omega-3 fatty acids such as linolenic acid is based on the reduction of the body’s immune defenses. As a result, there is an increased susceptibility to infection.