Tryptophan (Trp) is one of nine essential amino acids that must be taken in your daily diet.
Adult male tryptophan requires 4.0mg / kg (body weight).
Since the 1970s, it has been discovered that tryptophan affects the rate of formation of the neurotransmitter serotonin by nerve endings, and is also a precursor of melatonin, so tryptophan can help reduce mental stress and improve sleep The idea is incorporated.
Brain tryptophan is co-dependent on the plasma supply of tryptophan and carbohydrates (Fernstrom, 1983 & 1991).
Conversely, other large neutral amino acids (LNAA: tyrosine, phenylalanine, leucine, isoleucine, valine) are affected by circulating levels of blood, and tryptophan production depends on nutritional aspects.
Insufficient dietary tryptophan supply can cause rapid and severe brain serotonin loss.
Lack of tryptophan exacerbates the ability to cope with seasonal affective disorder, anxiety, carbohydrate craving, premenstrual syndrome and daily stress (Blokland et al., 2002).

The human tryptophan deficiency model suggests that the negative consequences of tryptophan deficiency are not only caused by serotonin deficiency, but mainly by complex interactions between monoaminergic systems (Reilly et al., 1997; Van der Does, 2001; Delgado, 2000).
However, there is still no consensus on the use of tryptophan as a supplement.
Comparative clinical trials have shown that tryptophan supplements alone or in combination with carbohydrates relieve stress (Maes et al., 1999) and reduce mild cognitive decline (Markus et al., 2002).

In addition, tryptophan is essential for the production of vitamin B3, and the production of converting enzymes requires vitamin B6, zinc and vitamin C.
Comparative clinical trials suggest that tryptophan or 5-hydroxytryptamine (a semi-product of the conversion to serotonin when it breaks down tryptophan) can help control overactive childhood in children (Rucklidge et al., 2009).

Unfortunately, due to the outbreak of eosinophilia myalgia syndrome (EMS) that suddenly occurred 21 years ago, human research has been put down.
This is related to a prescription-free tryptophan preparation that a company manufactured independently, and the most likely cause is an impurity caused by the company’s inadequate quality control.
As a result, tryptophan was banned in the US and UK until 2005.

Currently, ICAAS is intensively working on improving quality control methods to prevent the above-mentioned diseases in the future, and is focusing on providing consumers with potentially effective amino acids.
In addition, it supports both animal and human research models that help set the upper limit of allowable intake for tryptophan.

Finally, if the main diet of chicken and pigs is corn, tryptophan tends to be deficient.
Therefore, adding tryptophan to corn feed to increase the nutritional value will improve livestock productivity.

1.Blokland, A., Lieben, C. & Deutz, N. E. (2002). Anxiogenic and depressive-like effects, but no cognitive deficits, after repeated moderate tryptophan depletion in the rat. Journal of Psychopharmacology, 16, 39-49.
2.Delgado, P. L. (2000) Depression: the case for a monoamine deficiency. Journal of Clinical Psychiatry, 61, 7-11.
3.Fernstrom, J. D. (1991). Effects of the diet and other metabolic phenomena on brain tryptophan uptake and serotonin synthesis. Advances in Experimental Medicine and Biology, 294, 369-76.
4.Fernstrom, J. D. (1983). Role of precursos availability in control of monoamine biosynthesis in brain. Physiological Reviews, 63, 484-486.
5.Maes, M., Lin, A. H., Verkerk, R., Delmeire, L., Van Gastel, A., Van der Planken, M. & Scharpe, S. (1999). Serotonergic and noradrenergic markers of post-traumatic stress disorder with and without major depression. Neuropsychopharmacology, 20, 188-97.
6.Markus, C. R., Olivier, B. & de Haan, E. H. F. (2002). Whey protein rich in lactalbumine increases the ration of plasma tryptophan to the sum of the other large neutral amino acids and improves cognitive performance in stress-vulnerable subjects. American Journal of Clinical Nutrition, 75, 1051-1056
7.Reilly, J. G., MCTavish, S. F. & Young, A. H. (1997). Rapid depletion of plasma tryptophan: a review of studies and experimental methodology. Journal of Psychopharmacology, 11, 381-392.
8.Rucklidge, J. J., Johnstone, J., Kaplan, B. J. (2009). Nutrient supplementation approaches in the treatment of ADHD. Expert. Rev. Neurother. 9, 461-76.
9.Van der Does, A. J. (2001). The effect of tryptophan depletion on mood and psychiatric symptoms. Journal of Affective Disorders, 64, 107-119.

・Tryptophan as a help in depression
・Resurfacing tryptophan
・Ingestion of tryptophan-enriched cereal improves sleep at night, secretion of melatonin and serotonin, total antioxidant capacity, and emotion in the elderly


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