Lysine is one of the essential amino acids. It participates in numerous important body functions.
What is lysine?
Lysine (Lys or K) is a proteinogenic essential amino acid. Since the human body is unable to produce lysine itself, it must obtain the basic amino acid from food. Lysine forms an important building block for various proteins. These include transport proteins within the blood plasma, enzymes, hormones and antibodies. The same applies to the structural proteins of skin, tendons and bones, as well as the proteins myosin and actin, which are characteristic of muscles. Lysine is classified as a proteinogen because it is one of the 21 L-amino acids whose incorporation into proteins is regular. Thus, it is indispensable for the biosynthesis of proteins as well as for the maintenance of connective tissue and muscles. Due to its chemical structure, lysine is counted among the basic amino acids. Arginine and histidine also belong to these. Due to the composition of the three amino acids from a basic group as well as six carbon atoms, they also bear the name hexon bases.
Function, effect and tasks
Since lysine is involved in numerous proteins, it fulfills many important functions within the human organism. For example, it is essential for the stability of connective tissue collagens. In these structural proteins, lysine is hydroxylated and has OH residues at special sites, which in turn are cross-linked via sugar molecules. In this way, the stable glycoproteins can form, which are among the typical properties of collagen. The absorption of calcium into human bones and teeth is also influenced by lysine. Therefore, a diet rich in lysine is considered beneficial for people suffering from bone loss (osteoporosis). Lysine is also involved in other body processes such as the formation of hormones, enzymes and antibodies, tissue repair and growth. In addition, lysine ensures the maintenance of nitrogen balance within the body. The amino acid is also important for the immune system. Among other things, it has antiviral properties. Scientists also suspect that lysine plays a role in cardiovascular health. As a collagen component, it is extremely important for the walls of the blood vessels and strengthens the arterial walls. In addition, lysine ensures that lipoprotein a, which can lead to adhesion of the blood vessel walls if the concentration is too high, does not adhere to the walls of the arteries. Existing lipoprotein plaques are removed by the amino acid, which in turn counteracts cardiovascular problems. Thus, lysine is also classified as an efficient agent against arteriosclerosis. Medical research has successfully used lysine to treat herpes. As a result, the healing of cold sores proceeds more quickly.
Formation, occurrence, properties and optimal values
Lysine is absorbed into the human organism through the mouth. Subsequently, the amino acid reaches the intestinal wall with the help of various transporters. From there, it is distributed throughout the body. If there is an excess of lysine, it is excreted again via the kidneys. Lysine is primarily found in animal foods. This includes fish, eggs, milk and dairy products. Vegetables, however, contain only a small amount of the amino acid. Legumes such as lentils, peas and beans are an exception. In contrast, only little lysine is found in cereals and nuts. Here too, however, there are exceptions such as rice and buckwheat. Unlike other amino acids, lysine has an increased sensitivity to processing such as roasting or toasting. Foods rich in lysine include Parmesan cheese (3170 milligrams), tuna (2210 mg), pork (2120 mg), beef and shrimp (2020 mg each), wheat germ and soybeans (1900 mg each), lentils (1890 mg), and chicken (1790 mg) and peanuts (1100 mg). The daily requirement amount of lysine for adults is 14 milligrams per kilogram of body weight. In children, the requirement is three times higher. Between the ages of 10 and 12 years, 44 milligrams of lysine per kilogram are needed. To meet the need for lysine, a balanced diet is sufficient. A lysine deficiency usually only occurs in regions where mainly lysine-poor cereals are consumed.
Diseases and disorders
Both a deficiency and a significant excess of lysine can have an impact on human health. In the case of a lysine deficiency, there is a risk of disorders in the body functions for which lysine is important. These are primarily immune defense functions, nitrogen balance and body growth. A lysine deficiency can be caused by an unbalanced diet. Negative effects due to a lysine surplus are not to be feared in adult people who consume up to 4 grams of lysine per day. However, if the doses assume high proportions of 15 to 40 milligrams per day, there is a risk of diarrhea and intestinal cramps. If a person suffers from food intolerance to eggs, milk or wheat, these foods should be avoided. Lysine is also used by medicine as a therapeutic agent. Thus, the amino acid is used for the treatment and prevention of herpes. In this case, the patient takes between 1 and 3 grams of lysine a day. Furthermore, lysine is considered useful for the prevention of osteoporosis. The forms of administration range from capsules in dietary supplements to infusions. Possible side effects include blood sugar fluctuations, blood clotting disorders, and kidney dysfunction if overdosed continuously.
