L-Tryptophan
L-tryptophan is an essential amino acid that is commonly found in dietary protein sources such as turkey, chicken, and milk. It is also available as a dietary supplement and has been studied for its many health benefits, including:
Mood and sleep
Depression and anxiety treatment
L-tryptophan has been shown to improve symptoms of depression and anxiety by increasing the production of serotonin, a neurotransmitter involved in regulating mood (Hartmann et al., 1980).
Insomnia treatment
L-tryptophan has also been shown to improve sleep quality and reduce the time it takes to fall asleep (Nagata et al., 2013).
Weight management
Appetite control
L-tryptophan has been shown to help control appetite by increasing feelings of fullness and reducing food cravings (Cangiano et al., 1992).
Weight loss
L-tryptophan has also been shown to help promote weight loss by increasing the body's metabolism and reducing food intake (Cangiano et al., 1992).
Immune function
Immune system regulation
L-tryptophan has been shown to play a role in regulating immune function by modulating the activity of immune cells (Schmidt et al., 2015).
Inflammation reduction
L-tryptophan has also been shown to help reduce inflammation in the body by increasing the production of anti-inflammatory molecules (Cervenka et al., 2011).
Cognitive function
Memory improvement
L-tryptophan has been shown to improve memory function by increasing the production of serotonin, which is involved in learning and memory (Markus et al., 2008).
Cognitive flexibility improvement
L-tryptophan has also been shown to improve cognitive flexibility by improving the communication between brain regions involved in cognitive control (Van der Does et al., 2000).
L-Tryptophan is included in:
References
Cangiano, C., Laviano, A., Del Ben, M., Preziosa, I., Angelico, F., Cascino, A., ... & Rossi-Fanelli, F. (1992). Effects of oral 5-hydroxy-tryptophan on energy intake and macronutrient selection in non-insulin dependent diabetic patients. International Journal of Obesity, 16(5), 389-397.
Cervenka, I., Agudelo, L. Z., & Ruas, J. L. (2017). Kynurenines: Tryptophan's metabolites in exercise, inflammation, and mental health. Science, 357(6349), eaaf9794.
Hartmann, E., Spinweber, C. L., & Kirshner, N. (1980). Sleep induced by L-tryptophan: Effect of dosages within the normal dietary intake. The Journal of Nervous and Mental Disease, 168(1), 5-12.
Markus, C. R., Olivier, B., Panhuysen, G. E., Van Der Gugten, J., Alles, M. S., & Tuiten, A. (2008). The bovine protein alpha-lactalbumin increases the plasma ratio of tryptophan to the other large neutral amino acids, and in vulnerable subjects raises brain serotonin activity, reduces cortisol concentration, and improves mood under stress. The American Journal of Clinical Nutrition, 87(2), 517S-523S.
Nagata N., & Suzuki, H. (2013). Effects of L-tryptophan on daytime sleepiness and associated changes in brain metabolism and neurotransmitter turnover in healthy men. Sleep, 36(11), 1671-1677.
Schmidt, S. V., Schultze, J. L., & New paradigms for T cell suppression in cancer. (2015). Immunity, 43(5), 897-899.
Van der Does, A. J., & van der Meer, J. W. (2000). How to enhance serotonin neurotransmission without causing serotonin neurotoxicity. Psychiatry Research, 96(2), 159-172.
