Tryptophan
From Chempedia
Erin Radermacher, Dan Shapleigh
Tryptophan is an essential amino acid. An essential amino acid is not
naturally produced by the body so we must consume it through foods like
turkey. Not only is tryptophan found in turkey but also in mangoes,
cashews, milk, sweet potatoes, and nuts. Amino acids take their name from
the amino group (NH2) and because they can be hydrogen donors. To help
clarify, here is the chemical makeup of tryptophan:
(1)
(2)
C11H12N2O2
Tryptophan aids the body to synthesize the B-vitamin, niacin. With the new niacin created, the body produces Serotonin. "Serotonin is a chemical that acts as a calming agent in the brain and plays a roll in sleep."(?) A person that lacks the gene which produces an enzyme allowing Tryptophan to synthesize niacin to in turn produce serotonin, will experience an 80 percent loss of the neurotransmitter, serotonin. Patients clinically diagnosed with depression are 10 times more likely to carry this mutant gene than non-depressed patients. If one were diagnosed with low serotonin levels resulting in depression, a common treatment is prescribing a patient with SSRI drugs. Serotonin selective reuptake inhibitors are drugs that allow cells to uptake serotonin in the brain. This helps patients deal with many forms of depression. A mutant gene is responsible for the body’s inability to take up tryptophan. Genetic mutation results from a single base being other than what it should be. A study was conducted at Duke University which stated, "the mutant gene was carried by 87 depressed mice, 3 of 219 healthy controls and none of 60 bipolar disorder mice. This was reported by Drs. Marc Caron, Xiadong Zhang, and colleagues in January 2005." (3)(5)(7) The depressed mice showed 50-70 less serotonins. Genetic testing for tryptophan resistance can be a possible indicator of sensitivity to depression in an individual. "Once testing confirms sensitivity to tryptophan-serotonin production, serotonin-selective antidepressants can be prescribed for the sensitive individual." (6) Tryptophan is also the subject of an urban legend. Suggested myths state that it is concentrated in turkey and that eating large amounts of turkey, i.e., Thanksgiving is what causes post-feast stupor. Other suggestions may say that this stupor is caused from alcohol, a full stomach, and the metabolism working twice as hard to process the unusually large quantity of food that is ingested. Since tryptophan is an essential amino acid that resides in many other foods besides turkey, it is something that we consume on a daily basis. (5) Also, nutritionists do not believe that increasing the concentration of tryptophan within the body will increase the level of serotonin within the brain. It is not a good idea to take an excess amount of synthesized tryptophan to try and enhance your mood. It won’t work and it can be a possible threat to your health. Perhaps someday with further research, we could predict a patient’s genetic vulnerability to depression. This may be possible if we consider how tryptophan acts in the body. Because we know tryptophan has the ability to synthesize niacin which in turn produces serotonin in every individual, maybe we can learn more and help many patients.
Footnotes
[1] ([1] -u.ac.jp/trp.html)
[2] ([2] www.chemie.fu-berlin.de/chemistry
[3] ([3] dec2004/nimh-14.htm)
[4] Tryptophan Wikipedia (The Free Encyclopedia) en.wikipedia. org/wiki/Tryptophan
side link: [5] Tryptophan Biosynthesis www.chem.gvmt.as.uk/iubmb/enzyme/reaction/AminoAcid/Trp.html Will Eating Turkey make you Sleepy? The facts About the L-Tryptophan
[6] Lifeforce Yoga for Depression News- In the News- Mutant Gene Linked to Treatment - Resistant Depression. 5-13-2005. Paxil Progress. [4]
[7] Biocompare, Inc. Life Science News. Mutant Gene Linked to Treatment- Resistant Depression. 12/15/2004. Copyright 1998-2005. Source: NIH. [5]
[8] Index of/data/RIMS_data/VaporPressureNCEP. 10-04-05. [6]
[9] Altee High School on 2004-5-18
