Tryptophan is one of the essential amino acids. Its absorption into the human body occurs through food.
What is tryptophan?
Tryptophan (Trp) or L-tryptophan is the name given to a proteinogenic amino acid. It has an aromatic structure and is equipped with an indole ring system. Tryptophan is an essential amino acid. This means that it is not produced in the human body. For this reason, its supply through food is necessary. Tryptophan is an important component of numerous proteins. The human organism can synthesize various biogenic amines from the aromatic amino acid by decarboxylation. These include primarily serotonin, melatonin and tryptamine. Tryptophan is also used to treat mental and physical impairments because the important neurotransmitter serotonin is derived from the amino acid.
Function, effect and tasks
The amino acid tryptophan performs several important functions in the human organism. As already mentioned, it serves as a precursor for the tissue hormone serotonin, which is involved in numerous processes of the cardiovascular system, such as blood pressure. Serotonin exerts a different influence on the blood vessels, which is due to the local receptors. While the blood vessels of the muscles are dilated, their constriction occurs in the lungs and kidneys. Blood clotting and wound healing are also accelerated by tryptophan. The amino acid also has a positive influence on intestinal movements. Of particular interest is tryptophan as a mood enhancer. This effect comes about through the conversion of the amino acid into serotonin. Thus, tryptophan is extremely important for regulating the emotional state of people. Thereby positive effects on the well-being of humans take place. For this reason, serotonin is also regarded as a happiness hormone due to its mood-lifting properties. Tryptophan is another important precursor for the hormone melatonin, the production of which is reduced by daylight. Furthermore, tryptophan is involved in the synthesis of vitamin B3 (niacin). It acts as a provitamin and plays an important role in the metabolism of fats, carbohydrates, proteins and amino acids. It thus ensures the body’s energy supply. Tryptophan is also important for the formation of tissue and structural proteins. Since L-tryptophan also influences appetite, it can have a positive effect on weight reduction in overweight people on a diet. Preparations with tryptophan are also important for competitive athletes because they can increase their performance in this way. L-tryptophan is also a building block of various proteins. Indirectly, the amino acid also participates in numerous enzymatic reactions.
Formation, occurrence, properties and optimal values
Tryptophan is formed both naturally and by industrial production. Natural biosynthesis occurs in plants and microorganisms. In this process, the enzyme anthranilate synthase catalyzes the conversion of chorismate to anthranilate. This is followed by the cleavage of indole, from which tryptophan is subsequently produced with L-serine. In industrial production, the biosynthesis of L-tryptophan also occurs from L-serine and indole. For this purpose, manufacturers use a wild-type mutant of the bacterium Escherichia coli. Tryptophan is found in numerous foods. Unlike water-soluble vitamins, it is hardly lost during cooking. Thus, the amino acid has a strong heat resistance and is also not water-soluble. However, tryptophan is present only in bound form, so that only a fraction of its content enters the organism. Foods containing tryptophan in abundant amounts include dried peas, chicken eggs, soybeans, oatmeal, walnut kernels, cashews, cow’s milk, pork, salmon, cornmeal, unshelled rice, and unsweetened cocoa powder. As an amino acid, tryptophan is found primarily in plant and animal foods. For example, it is found in 100 grams of soybeans in an amount of 590 milligrams. Its content is also high in unsweetened cocoa powder and cashew nuts. The recommended dose of tryptophan is around 250 milligrams per day.
Diseases and disorders
If there are disturbances within the body in the transport or reabsorption of tryptophan, this not infrequently results in serious disease symptoms such as blue diaper syndrome (tryptophan malabsorption syndrome) or Hartnup’s disease. In tryptophan malabsorption syndrome, there are too low tryptophan levels in the blood. Since the tryptophan is not absorbed, it is bacterially broken down to indole, which is metabolized in the liver to indican. Contact with air causes the indican to turn blue, which in turn causes the affected babies to have their diapers colored accordingly. They also suffer from hyperphosphaturia, hypercalcemia, febrile episodes, and growth retardation. A deficiency of the amino acid also has a negative effect on health. Thus, those affected often experience depression, mood swings and anxiety disorders. The reason for this is dysfunction of the various messenger substances, which can no longer perform their tasks due to the deficiency symptoms. Possible causes of tryptophan deficiency include disorders of the amino acid’s absorption capacity, such as liver damage or gastrointestinal inflammation. It is not uncommon for a deficiency of tryptophan to lead to problems falling asleep and difficulty sleeping through the night. In addition, already existing irritable bowel syndromes are aggravated by a tryptophan deficiency. These complaints can be treated by targeted administration of the amino acid. No health consequences are to be feared from an overdose of tryptophan. Thus, the amino acid does not have toxic effects that have a negative impact on the body. In medicine, tryptophan is also used specifically against certain diseases. For example, it is considered effective in the treatment of steatohepatitis. In addition, the amino acid forms a significant natural antidepressant.
