On Mon, 20 Apr 1998, Kent Multer wrote:

> A couple of friends recently mentioned to me that there is a book that
> describes how people's blood type affects their health and diet; apparently
> there is one type in particular that just can't be healthy without eating
> some meat.
>
> Does anyone know more details about this?  If it's a reputable book (well
> researched, etc.), it could be another piece of eveidence from the
> mainstream medical world that supports the paleo viewpoint.

Kent, I have this book and have done at least a bit of research
into the subject.  The book is, as someone has already mentioned,
_Eat Right 4 Your Type_, by naturopathic physician Peter D'Adamo.
He runs a web site at www.dadamo.com.

Let me try to summarize the key points of D'Adamo's position.

1.  Type O blood is the oldest, going back to the first
appearance of humans.  It is the only true "paleolithic" blood
type.

2.  Type A blood came next, first appearing about 15-20,000 years
ago, but not proliferating until, and along with, the development
of agriculture, about 10,000 years ago.

3.  Types B and AB are still more recent, in that order.  They
are also less common.  Together they account for only about 15%
of the world's population.

4.  The ABO blood types are not *just* blood types.  They also
determine *tissue* sensitivity to various antigens.

5.  The ABO blood types are also correlated with other apparently
unrelated physiologic markers.  For example, Os have the highest
output of intestinal alkaline phosphatase, while As have the
lowest levels.  This enzyme is believed to play a role in the
digestion of fats.

6.  Gastric acid levels are also highest in Os and lowest in As.
D'Adamo claims that this is important because gastric acid helps
to initiate the digestion of protein.

7.  The ABO blood types are correlated with various diseases.
Type Os are more prone to infectious diseases, allergies, and
ulcers, for example.  Type As are more prone to heart disease and
certain cancers (but not all cancers).

8.  Lectins, which are immunoactive proteins that exist in fairly
high concentrations in plant foods and lower concentrations in
meats (but they're still there) affect the cells of tissues of
the ABO types differently.  That is, which lectins your body
identifies as "foreign" depends in part upon your blood type.
Thus, while virtually all dairy foods contain lectins that will
trigger an immune response in type Os, type As can tolerate a
very limited selection, while Bs and ABs can tolerate more.

9.  Eating foods that contain the "wrong" lectins for your blood
type can cause a variety of unwanted effects on health, including
chronic inflammation, autoimmunity, etc.  Thus, the fewer "wrong"
lectins you eat, the better.

10.  Some foods contain lectins that are actually beneficial for
certain blood types, because they facilitate some useful organic
process.  Soy, for example, is to be avoided by Os but is good
for As.  The same goes for peanuts.

11.  The proliferation of the ABO blood types represents an
ongoing adaptation to changing living conditions, including
agriculture, cities, etc.

Those are the main points.  D'Adamo has quite a bit of
documentation for the stuff about lectins and the immune system,
as well as the corrlations of blood type and disease patterns.
What he doesn't have, for obvious reasons, is much documentation
for points 8 through 10, since this would require large-scale
studies.

Interestingly, D'Adamo also cites the Eskimos as support for his
theories.  The Eskimos were a very isolated breeding population
consisting entirely of type Os.  In fact, isolated surviving
hunter-gatherers in the world today are all likely to be
exclusively type O because of their isolation.

Although type As are not "required" to be vegetarians, he claims
that they, of all the types will do best on a vegetarian or
near-vegetarian diet.  If they are to eat meat, they should
consume no beef or pork (because of lectins) but chicken, turkey,
and certain fish are okay.

I'm a type A myself.

Todd Moody
[log in to unmask]