Eicosapentaenoic acid is a polyunsaturated fatty acid. Like alpha-linolenic acid (ALA) and docosahexaenoic acid (DHA), it is one of the omega-3 fatty acids.
What is eicosapentaenoic acid?
Eicosapentaenoic acid (EPA) is a polyunsaturated long-chain fatty acid. In English, these fatty acids are also called polyunsaturated fatty acids (PUFAs). Since the first double bond is present at the third carbon bond, it is an omega-3 fatty acid. Although the body can produce EPA itself, it needs alpha-linolenic acid to do so. However, EPA can also be supplied with food. The fatty acid is found primarily in fatty marine fish such as herring, eel or mackerel.
Function, effect and tasks
Eicosapentaenoic acid plays a role in many metabolic processes. Eicosanoids and docosahexaenoic acid (DHA) are formed from the fatty acid. Eicosanoids are hormone-like substances that act as both neurotransmitters and immune modulators. They are involved in many inflammatory processes in the human body. These include, for example, vasodilatation, blood clotting and the regulation of inflammation. The regulation of blood pressure and cardiac activity in general are also influenced by eicosanoids. Prostaglandins, prostacyclins, thromboxanes and leukotrienes are among the eicosanoids. DHA is a fatty acid component of phospholipids. These in turn are a fundamental component of cell membranes and are found in particular in nerve cells. Thus, docosahexaenoic acid is needed primarily in the brain. But a lot of DHA is also found in the retina. Around 97 percent of all omega-3 fatty acids in the brain and almost 94 percent of all omega-3 fatty acids in the retina consist of docosahexaenoic acid. DHA is also a precursor for the synthesis of neuroprotectins, resolvins and docosatrienes. The fatty acid can lower blood pressure and heart rate, and therefore plays an important role in the treatment of hypertension.
Formation, occurrence, properties, and optimal values
The human body depends on the supply of alpha-linolenic acid (ALA) for the formation of EPA. ALA is found primarily in vegetable oils. Thus, linseed oil, rapeseed oil, soybean oil, walnut oil and hemp oil are rich in alpha-linolenic acid. EPA synthesis from alpha-linolenic acid is significantly more effective in women than in men. This can be attributed to estrogen. It seems to stimulate the synthesis of EPA from ALA. Healthy women convert about 21% of ingested ALA to EPA, whereas only about 8% is converted in men. However, for EPA to be synthesized from ALA, the enzymes delta-6-desaturase and delta-5-desaturase must be present in sufficient quantity and activity. In order for the desaturases to do their work, they require various micronutrients. In particular, vitamin B6, biotin, magnesium, zinc and calcium are important. A deficiency of these nutrients leads to reduced EPA synthesis. Synthesis is also inhibited by increased intake of saturated fatty acids, alcohol consumption, elevated cholesterol levels, viral infections, diabetes mellitus and stress. Less ALA is also converted in old age. However, EPA can not only be produced from ALA, but can also be ingested directly with food. The fatty acid is found primarily in fatty cold–water fish such as herring, sardines, salmon or mackerel. Some microalgae are also rich in EPA and DHA. The fatty acids are absorbed in the small intestine. An exact requirement for EPA has not yet been determined. The German Nutrition Society (DGE) recommends an intake of 250 milligrams per day. However, all long-chain omega-3 fatty acids fall under this intake recommendation. However, the DGE’s values are estimates and do not take into account individual dietary habits, health status or extraordinary stresses of the individual. Both the DGE and the German Federal Institute for Risk Assessment (BfR) consider an intake of about three grams of EPA per day to be safe. However, it is not only the absolute amount of omega-3 fatty acids consumed that counts; the ratio of omega-3 to omega-6 fatty acids should also be taken into account. At best, the ratio of omega-6 to omega-3 fatty acids should be 2:1 or at most 5:1. In the Western world, however, the ratio is often 15:1 or even 20:1.
Diseases and disorders
An unfavorable ratio favors cardiovascular diseases and rheumatic diseases.However, a deficiency of omega-3 fatty acids is often noticeable beforehand. However, the symptoms are rather uncharacteristic, so that an EPA deficiency cannot automatically be concluded. Possible symptoms of an EPA deficiency are muscle weakness, muscle tremors, sensitivity to light, scaly skin, concentration disorders, loss of performance, growth disorders or sleep disorders. The eicosanoids formed from eicosapentaenoic acid generally have an anti-inflammatory effect. A deficiency of EPA therefore often manifests itself in excessive inflammatory reactions or inflammatory reactions that hardly subside. An EPA deficiency should also be considered in allergic clinical pictures. Especially the type 1 allergy is meant here. In this immediate-type allergy, the body reacts to an allergen within minutes. Typical examples of this type of allergy are hay fever or allergic asthma. A deficiency of EPA also promotes the development of arteriosclerosis. Arteriosclerosis is the greatest risk factor for heart attack and stroke. A deficiency of omega-3 fatty acids and thus also of eicosapentaenoic acid also appears to play a role in skin diseases such as atopic dermatitis or psoriasis. A decrease in erythema was observed in psoriasis patients taking fish oil as a dietary supplement. The thickness of the plaques also decreased and the scaling of the skin was much easier. In addition, the agonizing itching decreased. Similar results were seen in atopic dermatitis. EPA can also have an alleviating effect in chronic inflammatory bowel diseases such as Crohn’s disease or ulcerative colitis.
