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The Blood Type Diet Archives Volume 3

Blood types and brain stuff [long post]

Posted By: Peter D'Adamo
Date: March-24, 1998 at 15:34:50

Many people ask why type O's are not recommended to use St Johns Wort. Aside from the fact that the two cases of "photosensitization" which I have observed have occured in this blood type, there is another, more important reason. Type O's have lower levels of the enzyme MAO, and St. Johns Wort is an MAO inhibitor. This perhaps explains why many type Os on St Johns Wort say they feel "weird" or have disturbing dreams. I have however been finding that type O's with mild to moderate depression do benefit from the amino acid tyrosine (which can boost dopamine levels), and arginine (which is used to recycle nitrous oxide in the nervous system). Also, the gene for the enzyme dopamine beta hydroxylase sits right on top of the ABO gene and there are indications that this may cause psychiatric syndromes to be somewhat related to ABO blood group. Maybe those Japanese personality observations were not so off-the-wall after all?

Also, studies show distinct differences in blood type and hormonal response to stress. Type A, for instance responds to stress with higher levels of cortisol than the other types. It is interesting to also note that the one form of exercise shown to increase urinary excretion of cortisol is- you guessed it - yoga.


Acta Psychiatr Scand 1983 Feb;67(2):130-134
Reduced platelet MAO activity in healthy male students with blood group O.
Arato M, Bagdy G, Rihmer Z, Kulcsar Z

The association between the two genetic markers of affective disorders, ABO blood group system and platelet MAO (monoamine oxidase) activity was studied in 70 healthy young males. The platelet MAO activity of subjects with blood type O was significantly lower than that of subjects with blood type A and with blood types A + B AB + B together. This finding could constitute a "bridge" between the two genetic approaches to affective disorders.

Am J Hum Genet 1988 Jan;42(1):160-166
Linkage of a gene regulating dopamine-beta-hydroxylase activity and the ABO blood group locus.
Wilson AF, Elston RC, Siervogel RM, Tran LD
Department of Biometry and Genetics, Louisiana State University Medical Center, New Orleans 70112.

Previous studies have presented evidence suggesting that levels of dopamine-beta-hydroxylase (DBH) activity are controlled by a gene linked to the ABO blood group locus. In this study, linkage analyses in four large families of whites and one family of blacks were performed on the untransformed and on the square root--and natural log--transformed DBH activity. In the families of white individuals, the results of both the sib-pair and lod-score linkage analyses strongly indicate that a gene regulating DBH activity is linked to the ABO blood group locus on chromosome 9q (i.e., lod score 5.88 at a recombination fraction of .0).

Biol Psychiatry 1994 Oct 1;36(7):434-442
A linkage study of affective disorder with DNA markers for the ABO-AK1-ORM linkage group near the dopamine beta hydroxylase gene.
Sherrington R, Curtis D, Brynjolfsson J, Moloney E, Rifkin L, Petursson H, Gurling H
Academic Department of Psychiatry, University College, London, U.K.

Combining data from a number of studies has provided evidence for a susceptibility allele for affective disorder near to the ABO-AK1-ORM region on chromosome 9q34. The dopamine beta hydroxylase gene locus is also at 9q34. Five multigenerational families with bipolar and unipolar affective disorder were analyzed for linkage with highly polymorphic microsatellite markers from the candidate region. The segregation of the illness in these families was compatible with an autosomal dominant susceptibility allele.

Clin Biochem 1985 Feb;18(1):67-69
Cortisol and catecholamines response to venisection by humans with different blood groups.
Locong AH, Roberge AG

Hormonal response following a minor physiological stress induced by bleeding in a blood donor clinic was investigated in 134 humans with different blood groups. After venisection, serum cortisol concentration (mean +/- SD) was found highest in blood group A donors (455 +/- 217 nmol/L), followed by group B (364 +/- 206), AB (325 +/- 154) and O (297 +/- 110). In 14 subjects of blood group A compared to an equal number of blood group B subjects, mean plasma adrenaline level was higher in group A (0.23 +/- 0.09 nmol/L) than in group B (0.15 +/- 0.12) but the difference was not statistically significant. Blood group A individuals responded to a stressful situation with higher levels of cortisol, and possibly of adrenaline. These observations tend to support findings of previous studies demonstrating a high risk of diseases related to stress (coronary heart diseases and gastrointestinal diseases), in men with A blood group.

Neuropsychobiology 1986;16(1):43-46
Influence of ABO blood type on symptomatology among outpatients: study and replication.
Boyer WF
Two independent samples of psychiatric outpatients (n = 52 and 60) with blood type A or O completed the Brief Symptom Inventory, an abbreviated version of the SCL-90. In both samples patients with blood type A scored significantly higher than those with type O on the 'Obsessive-Compulsive' and 'Psychoticism' factors. These findings are not attributable to differences in age, sex or diagnosis, and are consistent with several previous studies. The influence of blood type on symptom expression may be mediated by cell membrane characteristics.

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