Tryptophan

From MEpedia, a crowd-sourced encyclopedia of ME and CFS science and history

Tryptophan is an essential amino acid and is used in the body to help make the B vitamin niacin, the hormone melatonin, and the neurotransmitter serotonin.[1]

L-tryptophan was formerly used as a dietary supplement to help relieve insomnia and depression.[2] There is insufficient evidence for the use of L-tryptophan to improve sleep or depression.[3]

Importance to ME/CFS[edit | edit source]

By mediating tryptophan catabolism, the enzyme indoleamine-2,3-dioxygenase (IDO) has a complex role in immunoregulation in infection and autoimmunity.[4] The ME/CFS Severely Ill, Big Data Study of found IDO genes defects in most of the small group with severe ME that was studied, which may prevent people with ME/CFS from metabolising tryptophan, leading to increased levels in patients.[5]

Dr. Ron Davis, speaking about tryptophan being available on the market, has made it clear that self experimentation can be very dangerous.[5]

Learn more[edit | edit source]

The 15th Conference of the International Society of Tryptophan Research was held at The University of Shiga Prefecture, which is situated in Hikone city, 30 miles east of Kyoto, Japan. The conference was a venue for tryptophan research including cancer, immunology, neuroscience, pathology, pharmacology, physiology, clinical diagnosis, nutrition, food science, analytical chemistry and L- tryptophan metabolism.[6]

Notable studies[edit | edit source]

  • 2010, Sex differences in plasma prolactin response to tryptophan in chronic fatigue syndrome patients with and without comorbid fibromyalgia[7] (Full text)
  • 2011, Kynurenine pathway Hypothesis: The nature of the chronic Fatigue syndrome (cFs) Revisited[8] (Full text)
  • 2012, A Brief Historic Overview of Clinical Disorders Associated with Tryptophan: The Relevance to Chronic Fatigue Syndrome (CFS) and Fibromyalgia (FM)[9] (Full text)
  • 2014, Tryptophan depletion in chronic fatigue syndrome, a pilot cross-over study[10] (Full text)
  • 2014, Biological phenotypes underpin the physio-somatic symptoms of somatization, depression, and chronic fatigue syndrome[11] (Abstract)
  • 2014, Physiosomatic complaints, immune-inflammatory pathways, and serotonin-related mood symptoms: relevance for tryptophan-related challenge procedures and clinical considerations with respect to the DSM-V[12] (Comment on 2014, "Biological phenotypes underpin...")
  • 2016, The Many Neuroprogressive Actions of Tryptophan Catabolites (TRYCATs) that may be Associated with the Pathophysiology of Neuro-Immune Disorders[13] (Abstract)

See also[edit | edit source]

References[edit | edit source]

  1. "Tryptophan: MedlinePlus Medical Encyclopedia". medlineplus.gov. Retrieved April 16, 2019.
  2. "Definition of L-TRYPTOPHAN". Merrian-Webster Dictionary. Retrieved November 17, 2018.
  3. "L-Tryptophan: MedlinePlus Supplements". medlineplus.gov. Retrieved November 17, 2018.
  4. Bozza, Silvia; Fallarino, Francesca; Pitzurra, Lucia; Zelante, Teresa; Montagnoli, Claudia; Bellocchio, Silvia; Mosci, Paolo; Vacca, Carmine; Puccetti, Paolo; Romani, Luigina (March 2005). "A Crucial Role for Tryptophan Catabolism at the Host/Candida albicans Interface". Journal of Immunology. 174 (5): 2910–2918. doi:10.4049/jimmunol.174.5.2910.
  5. 5.0 5.1 Davis, Ronald (November 7, 2018). "Ronald W. Davis, PhD | What's next?". YouTube. Open Medicine Foundation - OMF.
  6. http://www.istry2018.com/
  7. Weaver, Shelley A.; Janal, Malvin N.; Aktan, Nadine; Ottenweller, John E.; Natelson, Benjamin H. (May 2010). "Sex differences in plasma prolactin response to tryptophan in chronic fatigue syndrome patients with and without comorbid fibromyalgia". Journal of Women's Health (2002). 19 (5): 951–958. doi:10.1089/jwh.2009.1697. ISSN 1931-843X. PMC 2875960. PMID 20384451.
  8. Blankfield, Adele (July 31, 2011). "Kynurenine pathway Hypothesis: The nature of the chronic Fatigue syndrome (cFs) Revisited". International Journal of Tryptophan Research : IJTR. 4: 47–48. doi:10.4137/IJTR.S7898. ISSN 1178-6469. PMC 3195222. PMID 22084603.
  9. Blankfield, Adele (September 17, 2012). "A Brief Historic Overview of Clinical Disorders Associated with Tryptophan: The Relevance to Chronic Fatigue Syndrome (CFS) and Fibromyalgia (FM)". International Journal of Tryptophan Research : IJTR. 5: 27–32. doi:10.4137/IJTR.S10085. ISSN 1178-6469. PMC 3460668. PMID 23032646.
  10. The, Gerard K. H.; Verkes, Robbert J.; Fekkes, Durk; Bleijenberg, Gijs; van der Meer, Jos W.M.; Buitelaar, Jan K. (September 16, 2014). "Tryptophan depletion in chronic fatigue syndrome, a pilot cross-over study". BMC research notes. 7: 650. doi:10.1186/1756-0500-7-650. ISSN 1756-0500. PMC 4176591. PMID 25227994.
  11. Anderson, G.; Berk, M.; Maes, M. (February 2014). "Biological phenotypes underpin the physio-somatic symptoms of somatization, depression, and chronic fatigue syndrome". Acta Psychiatrica Scandinavica. 129 (2): 83–97. doi:10.1111/acps.12182. ISSN 1600-0447. PMID 23952563.
  12. von Polier, G. G.; Zepf, F. D. (February 2014). "Physiosomatic complaints, immune-inflammatory pathways, and serotonin-related mood symptoms: relevance for tryptophan-related challenge procedures and clinical considerations with respect to the DSM-V". Acta Psychiatrica Scandinavica. 129 (2): 98–99. doi:10.1111/acps.12197. ISSN 1600-0447. PMID 24117193.
  13. Morris, Gerwyn; Carvalho, André F.; Anderson, George; Galecki, Piotr; Maes, Michael (2016). "The Many Neuroprogressive Actions of Tryptophan Catabolites (TRYCATs) that may be Associated with the Pathophysiology of Neuro-Immune Disorders". Current Pharmaceutical Design. 22 (8): 963–977. ISSN 1873-4286. PMID 26667000.