A while back I mentioned Peter D'Adamo's theory that the ABO
blood groups represent not only adaption to infectious disease
but also adaptation to dietary changes.  Although the core of his
theory is that dietary lectins affect tissues differently in the
different blood ABO types, he asserts that there are also other
differences that have dietary implications.  If he is correct,
this would have considerable significance, since the ABO types
would correlate with the transition to post-paleo eating
patterns.

One of the claims that he makes is that gastric acid levels are
highest in type Os and lowest in type As.  Another claim is that
concentrations of the intestinal enzyme alkaline phosphatase are
also highest in Os and lowest in As.  I asked for references, and
he kindly provided a few.  For those who might be interested in
this sort of thing, here they are:

J. Steen, et al.  Basal serum gastrin concentration related to
complications, blood groups, and season in duodenal ulcer.
Scand J Gastroentero.  1982 Jun; 17(4): 529-532.

GP Jori, et al.  Influence of blood group and secretor status on
gastric acidity.  Am J Dig Dis. 1969 Jun; 14(6): 380-384.

MA Demborough.  ABO glood group, secretor status and gastric
secretion.  Australas Ann Med. 1966 Nov; 15(4): 314-317.

U Domar, K Hirano and T Stigbrand.  Serum levels of human
alkaline phosphatase isozymes in relation to blood groups. Clin
Chim Acta; 203(2-3) 1991 Dec 16.

AP Day, et al.  Triglyceride fatty acid chain length influences
the post prandial rise in serum intestinal alkaline phosphatase
activity.  Ann Clin Biochem; 29(pt 3): 287-92 1992 May.

The basic idea is that lower levels of gastric acid diminish
one's ability to digest animal protein, and lower levels of ALP
diminish one's ability to digest fats and cholesterol.

The A group appeared about 20K years ago, but didn't really
proliferate until agricultural times.  B and AB came later.  If
the theory is right, the A blood type would have been a liability
to hunter-gatherers, but perhaps the disadvantage was outweighed
by the advantage of greater resistance to infection, as compared
to the O type.  When agriculture arrived, the A type turned out
to have a secondary advantage, the ability to make better use of
non-meat protein sources, such as legumes, as compared with type
O.  The later B and AB types would represent more complete
adaptation to agricultural and pastoral diets.  For example, B
blood is common in semitic peoples who have had domesticated
herds for a long time.  Supposedly they also tolerate dairy foods
well.

I am ignoring the whole lectin dimension and looking solely at
the ABO-linked phenotype considerations.  Does any of this make
sense?

Todd Moody
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