Abnormal Tryptophan Metabolism in Neuropsychiatric Diseases

The bibliography gives general background material to this complex subject.

"Catabolism of tryptophan and tyrosine in relation to the isoprenoid pathway was studied in neurological and psychiatric disorders. The concentration of trytophan, quinolinic acid, kynurenic acid, serotonin and 5-hydroxyindoleacetic acid was found to be higher in the plasma of patients with all these disorders..." Ravikumar et al (2000)

This group from India found excessive metabolites of tryptophan in schizophrenia, multiple sclerosis, and Parkinson's disease. All three diseases can present with psychiatric symptoms, but MS and Parkinson's are considered neurological. In Parkinson's disease there is a deficiency of dopamine.

"There was increase in free fatty acids ..." Ravikumar et al (2000)

The entire article from India is available for free on the Internet. See #1 in the bibliography. In fact the whole journal (Neurology India) is available for free on the Internet. All of my articles are also available for free on the Internet. Some are on Gather and some are on Associated Content. A few are at http://www.m-power.org/. If you go to http://www.m-power.org/, look up Voices for Change. My articles are in Voices for Change.

Tryptophan

The British group, Wood K, Swade C, and Coppen A, reported "tryptophan accumulation by blood platelets of depressed patients".

"The accumulation of tryptophan by the platelet is significantly greater in the acutely depressed patients than the control group." Wood et al

See #7 in the bibliography.

Lactate

Article #8 in the bibliography reported lower brain pH in schizophrenics and increased lactate. The lower pH was thought to be due to increased lactic acid. The excess lactic acid could come from tryptophan because it is a glucogenic amino acid. This means that it can produce carbohydrate intermediates.

"These data suggest that lactate increases in postmortem human brain of patients with schizophrenia are associated with decreased pH ..." Nader D. Halim et al

Mitochondria

There is a strong theory that schizophrenia is a disease of the mitochondria. The mitochondria produce energy for the cell. This energy is stored in the form of ATP. This theory is compatible with the tryptophan theory. Excessive tryptophan could disrupt the mitochondria.

"Recent findings of mitochondrial abnormalities in brains from subjects with neurological disorders have led to a renewed search for mitochondrial abnormalities in psychiatric disorders. A growing body of evidence suggests that there is mitochondrial dysfunction in schizophrenia, bipolar disorder, and major depressive disorder, including evidence from electron microscopy, imaging, gene expression, genotyping, and sequencing studies." Shao L et al

See #10 in the bibliography.

Food

Trptophan is found in the following foods:

Bananas, beans, brewer's yeast, brown rice bran, caseinate, cottage cheese, dairy products, dates, eggs, fish, lactalbumin, legumes, meat, milk, nuts, peanuts, protein (hydrolysis), seafood, seeds, soy, turkey, whey, whole grains.

A low tryptophan diet is suggested which avoids these foods.

Conclusions

More research is needed. A tryptophan depletion diet might help, but it is highly possible that other amino acids may also be involved in psychiatric diseases. Thus a low protein diet is another possiblity. Gelatin has no tryptophan, but it has other amino acids.

Bibliography

1. http://www.neurologyindia.com/article.asp?issn=0028-3886;year=2000;volume=48;issue=3;spage=231;epage=8;aulast=Ravikumar

2. Ravikumar A, Deepadevi KV, Arun P, Manojkumar V, Kurup PA. Tryptophan and tyrosine catabolic pattern in neuropsychiatric disorders. Neurol India 2000;48:231.

3. www.associatedcontent.com/article/942267/abnormal_psychology_the_etiology_of.html

4. www.associatedcontent.com/article/931767/the_interpretation_of_abnormal_lymphocytes.html

5. www.associatedcontent.com/article/929351/thoughts_on_bipolar_disorder.html?t=72

6. www.associatedcontent.com/article/905903/the_human_brain_and_its_afflictions.html

7. Wood K, Swade C, Coppen A. Tryptophan accumulation by blood platelets of depressed patients. J Neural Transm Suppl. 1979;(15):161-3.

8.Increased lactate levels and reduced pH in postmortem brains of schizophrenics: Medication confounds
Journal of Neuroscience Methods, Volume 169, Issue 1, 30 March 2008, Pages 208-213
Nader D. Halim, Barbara K. Lipska, Thomas M. Hyde, Amy Deep-Soboslay, E. Michael Saylor, Mary M. Herman, Jay Thakar, Ajay Verma and Joel E. Kleinman

9. http://find.galegroup.com/itx/infomark.do?&contentSet=IAC-Documents&type=retrieve&tabID=T002&prodId=HRCA&docId=A175665469&source=gale&userGroupName=nee&version=1.0>.

10. Ann Med. 2008;40(4):281-95.Links Mitochondrial involvement in psychiatric disorders. Shao L, Martin MV, Watson SJ, Schatzberg A, Akil H, Myers RM, Jones EG, Bunney WE, Vawter MP.

Department of Psychiatry & Human Behavior, University of California, Irvine, Irvine CA, USA.