Arachidonic acid belongs to the polyunsaturated fatty acids. It is semiessential for the body. Arachidonic acid is found predominantly in animal fats.
What is arachidonic acid?
Arachidonic acid is a quadruply unsaturated fatty acid and belongs to the omega-6 fatty acids. Omega-6 fatty acids serve as precursors to prostaglandins and thus play an important role in inflammatory processes. The majority of the requirement for arachidonic acid is covered by food. The fatty acid is found primarily in products of animal origin. However, arachidonic acid can also be synthesized from another omega-6 fatty acid. Anti-inflammatory drugs often target the metabolism of arachidonic acid.
Function, effects, and roles
Omega-6 fatty acids, and therefore arachidonic acid, are vital to the body. They serve as building blocks for various substances in the body. Other fatty acids are also built from omega-6 fatty acids. The unsaturated fatty acids also perform important functions in the construction of cell membranes. They are responsible for the flexibility of cell walls. Fatty acids also play an important role in skin metabolism. They can counteract skin irritation and eczema formation. Arachidonic acid is also said to reduce the size of blackheads. The fatty acid also helps transport oxygen through the lungs. Arachidonic acid is also important for nerve and brain cells. It maintains the healthy structure of cell membranes and thus also protects against neurological diseases. Arachidonic acid also plays an important role in immune defense and wound healing. The body also produces the so-called eicosanoids from arachidonic acid. Eicosanoids are messenger and signal substances that influence many processes in the body. These include, for example, hormone and inflammatory processes. Depending on the dosage, arachidonic acid can promote or alleviate inflammation. The condition of the individual also seems to play a role in determining the effect of arachidonic acid when it is metabolized.
Formation, occurrence, properties, and optimal levels
Arachidonic acid can only be partially formed by the body itself. The majority of arachidonic acid comes from food. If the body has sufficient amounts of linoleic acid, it can also convert it to arachidonic acid. Arachidonic acid is mainly found in animal foods. Rich in arachidonic acid are chicken meat, pork liver, veal, sausage, omelettes, milk, eel and croissants. The German Nutrition Society (DGE) recommends a ratio of 1:5 for the intake of omega-3 and omega-6 fatty acids, which means that people should consume five times more omega-6 than omega-3 fatty acids. However, the reality is currently different. Due to current dietary habits, the ratio is usually 1:10. In this unhealthy ratio, arachidonic acid often shows its pro-inflammatory properties.
Diseases and disorders
People suffering from a rheumatic disease should avoid foods with a high arachidonic acid content on a mandatory basis. An example of such a disease is rheumatoid arthritis. In rheumatoid arthritis, the joints are affected by persistent inflammation. These inflammations are caused and maintained by inflammatory mediators. The inflammatory mediators are also called eicosanoids. They include, for example, prostaglandins, leukotrienes or thromboxanes. The body itself forms all these inflammatory mediators from arachidonic acid. Without arachidonic acid, such strong and above all permanent inflammatory processes would hardly be possible. A reduced intake of arachidonic acid can therefore have a positive effect on the course of rheumatic diseases. Eicosapentaenoic acid, also known as EPA for short, also has a positive effect. Its chemical structure is similar to that of arachidonic acid and it therefore binds to the same cell receptors as arachidonic acid. In contrast to the pro-inflammatory fatty acid, however, EPA does not trigger the formation of inflammatory mediators. Arachidonic acid and EPA therefore compete for the same enzymes, so that EPA can have an anti-inflammatory effect in this way. This is also referred to as competitive inhibition. EPA belongs to the omega-3 fatty acids and is mainly found in vegetable oils such as rapeseed oil, soybean oil, linseed oil or safflower oil. A diet low in arachidonic acid is also recommended for patients with multiple sclerosis.Multiple sclerosis is a chronic inflammatory disease of the nervous system. Here, the myelin sheaths of the nerve cells become inflamed, so that the transmission of impulses is disturbed. Numerous symptoms such as paralysis, weakness, depression, incontinence, speech disorders or visual disturbances can be the result. Arachidonic acid can fuel these inflammatory processes and thus lead to an aggravation of symptoms. Of course, diseases can also result from a deficiency of arachidonic acid. A deficiency of fats can arise in different ways. A very one-sided diet or a long-term fat-free diet can result in a fat deficiency. But diseases of the gastrointestinal tract can also lead to a deficiency. One example of such a disease is pancreatic insufficiency. Here, the pancreas no longer produces sufficient digestive enzymes. Fat-cleaving enzymes are also no longer present in sufficient quantities. As a result, the ingested dietary fats cannot be properly utilized and are partially excreted undigested. This can also be seen in the patients’ stools. The stool is often shiny, greasy and very voluminous. This is also referred to as fatty stool. A lack of fats can lead to a lack of energy. The metabolism shuts down and those affected lose a significant amount of body weight. In the case of a deficiency of omega-6 fatty acids, patients suffer from visual disturbances, muscle weakness and poor cognitive performance. Skin diseases, impaired wound healing, increased susceptibility to infections, anemia and respiratory problems can also be the result of a deficient supply of omega-6 fatty acids, such as arachidonic acid.