Omega-6 fatty acids belong to the group of unsaturated fatty acids. They are essential for the body, which means that they must be supplied with food.
What are omega-6 fatty acids?
Omega-6 fatty acids are polyunsaturated fatty acids. The most important omega-6 fatty acids are linoleic acid (LA), gamma-linolenic acid (GLA), dihomo-gamma-linolenic acid (DHGLA), and arachidonic acid (AA). In their chemical structure, omega-6 fatty acids have more than one double bond. Unlike omega-3 fatty acids, omega-6 fatty acids have their first double bond at the sixth carbon atom. Linoleic acid is essential for the body. All other omega-6 fatty acids can be derived from this fatty acid.
Function, effect and tasks
The essential fatty acids are vital to the body. For example, linoleic acid plays a role in oxygen transport. Together with various sulfur-containing enzymes, it can activate absorbed oxygen and hemoglobin formation. Hemoglobin is the red blood pigment. It is composed of various proteins and can bind oxygen. In addition, unsaturated linoleic acids are an important component of cell membranes. Only a regular supply of linoleic acid keeps the cell walls flexible and elastic. In addition, linoleic acid is important for the health of the skin. Prostaglandins are also formed from linoleic acid. These not only regulate cholesterol levels, they also support the function of red blood cells. In addition, linoleic acid can transport fat-soluble toxins to the excretory organs of the skin, lungs, kidneys and intestines. Gamma-linolenic acid is also a component of cell membranes. Like linoleic acid, gamma-linolenic acid plays an important role in skin health. When gamma-linoleic acid is applied externally, the skin becomes more supple. When used internally, the skin’s natural barrier function is strengthened. Gamma-linolenic acid can also have a soothing effect on some skin diseases, such as neurodermatitis or acne. However, it is also needed for the production of so-called eicosanoids. Dihomo-gamma-linolenic acid and arachidonic acid are also converted into eicosanoids. Eicosanoids are hormone-like substances that act as neurotransmitters or immune modulators. They are particularly involved in inflammatory processes in the body. Eicosanoids can be divided into four groups: Prostaglandins, prostacyclins, thromboxanes and leukotrienes. With the help of omega-6 fatty acids, these substances can be produced by any cell. They play an important role in blood clotting, in the development of fever, in allergic reactions, in the development of pain or in inflammation. While the function of omega-6 fatty acids as inflammatory mediators is important, excessive intake of omega-6 fatty acids can also promote inflammation and vasoconstriction in the body due to the inflammatory mediators that are produced. Not all eicosanoids, however, have a pro-inflammatory effect. Some of the messenger substances even have anti-inflammatory properties. Arachidonic acid is found in male sperm and is needed for the formation of the hormone testosterone. Conjugated linoleic acid has a strong antioxidant effect. It has a positive effect on glucose and fat metabolism and can prevent arteriosclerosis, as it can reduce the level of blood fats. It can also prevent diabetes mellitus as it has a regulating effect on blood glucose levels. Some studies show that conjugated linoleic acid even has anticarcinogenic effects, that is, against cancer cells.
Formation, occurrence, properties and optimal values
Omega-6 fatty acids are essential for the body. Linoleic acid, in particular, cannot be produced by the human body, and it relies on dietary intake. The other omega-6 fatty acids can be partially synthesized from linoleic acid. Linoleic acid is naturally found in cold-pressed vegetable oils such as corn germ oil, black cumin oil, soybean oil, sunflower oil, wheat germ oil or safflower oil. The most important gamma-linolenic acid sources are evening primrose oil, borage oil and black currants. Alpha-linolenic acid is found in green leafy vegetables, linseed oil, canola oil and soybean oil. Eicosapentaenoic acid and docosahexaenoic acid, two metabolites of alpha-linolenic acid, are found in fatty fish such as mackerel, salmon and herring. The polyunsaturated fatty acids are also found in meat and milk. Here, however, the amount is strongly dependent on the feed of the animals.According to the recommendations of the German Nutrition Society (DGE), an adult should obtain 30% of his or her daily energy intake from fats. The proportion of essential fatty acids should be around 3.5%. Essential fatty acids include not only omega-6 fatty acids, but also omega-3 fatty acids. The ratio of omega-6 to omega-3 fatty acids should be between 5:1 and 15:1. However, most people consume ten to twenty times more omega-6 fatty acids than omega-3 fatty acids.
Diseases and disorders
A deficiency of omega-6 fatty acids can cause skin disorders. Inflammatory dry eczema is typical. Hair loss is also observed. Other consequences of a deficiency include increased susceptibility to infections, wound healing disorders, and cardiovascular complaints. Severe deficiency symptoms include impaired liver metabolism, kidney tissue destruction, and female and male sterility. However, a deficiency of omega-6 fatty acids is rather rare. Normally, sufficient fatty acids are ingested with food. A deficiency of gamma-linoleic acid usually occurs due to increased consumption. This can be the case with lack of exercise, excessive alcohol consumption or heavy smokers. Diseases of the digestive tract that result in chronic malabsorption can also cause a deficiency of omega-6 fatty acids. Unborn and newborn babies are particularly sensitive to such a deficiency. In most cases, however, the amount of omega-6 fatty acids in the diet is too high. Excessive intake leads to increased production of eicosanoids. This can lead to increased inflammation in the body. A disproportion to the disadvantage of omega-3 fatty acids is also suspected of increasing the risk of stroke and cancer.
