Ask. Dr. D'Adamo

QUESTION: What is the Bombay phenotype? I understand it to make some people type O. Is that true?

ANSWER: ABO blood type antigens are produced by ABO enzymes that are coded by our ABO genes. Type O does not make a true antigen, although they do make 'H' which is used by the other blood types as the basic bulding block. Thus, even A's and B's make H (in addition to their own A or B antigen), whilst O only makes H.

An interesting situation arises when an individual is not able to make the "H" antigen. Such a person cannot produce the "H" antigen and even if the "A" or "B" enzymes are present, cannot make "A" or "B" antigen since there is no precursor for the antigens to act upon. An individual who cannot produce the "H" antigen will appear to have blood type "O" since this blood type is a negative category (not- A, not- B, not- A and not- B ). This was first documented in Bombay and has become known as the Bombay phenotype.

The Bombay phenotype group derives the name "Bombay" because it was first discovered to exist among some people living in the region of Bombay, India. Although the group is more likely to occur in East Indians, it is a very rare group even among this population. Also, it is not restricted to East Indians and has been found to exist in Caucasians, Negroes, Japanese, etc.

QUESTION: I have been reading some information by a group that advocates an all or mostly all raw vegetarian diet. In telling of the ills of meat they mention the build up of uric acid in the colon which will eventually lead to disease. I am a type O. Will a type O have this problem with uric acid.

ANSWER: You can read nutritional information of virtually any opinion on essentially any subject. Remember, that is the power of our polymorphism paradigm: It allows us to filter out the excessive rant of 'cure all's' and further reductionist statements.

A quick check of MEDLINE showed no studies indicating that a high protein diet in appropriate circumstances (i.e farm raised, chemical free meat) led to any rise in uric acid levels in the intestines. On the contrary, there is actually more speculation that low uric acid levels may be associated with higher risks for cancer (1) although even this has been disputed (2).

I suppose if you ate a diet of exclusively of meat you could theoretically raise your intestinal level of uric acid, but that diet is impossible to consume, and the vegetables and fruits abundantly found in the type O diet themselves modulate levels of urates and uric acids (3).



1. Mazza A, Casiglia E, Scarpa R, Tikhonoff V, Pizziol A, Sica E, Pessina AC. Predictors of cancer mortality in elderly subjects. Eur J Epidemiol. 1999 May;15(5):421-7.

2. Hiatt RA, Fireman BH. Serum uric acid unrelated to cancer incidence in humans. Cancer Res. 1988 May 15;48(10):2916-8.

3. Jenkins DJ, Popovich DG, Kendall CW, Rao AV, Wolever TM, Tariq N, Thompson LU, Cunnane SC. Metabolic effects of non-absorbable carbohydrates. Scand J Gastroenterol Suppl. 1997;222:10-3.