On Thu, 23 Apr 1998, Kent Multer wrote:
> I don't have the technical expertise you do about lectins and such; but it
> seems (my take on his take?) that basically, the difference between one
> blood type and another isn't that big a deal. Whatever type you are, you
> still run a higher risk of getting the "diseases of civilization" if you
> eat non-paleo foods. Types other than O may have somewhat less risk for
> some foods, but they're not home free.
>
> But I don't have many facts to back this up (Ray's note didn't say much
> beyond what I quoted). Those of you who have read D'Adamo's book, got
> anything to add?
Here's an example of some of the lectin-related research that
D'Adamo uses:
Eur J Clin Nutr 1993 Oct;47(10):691-699
Dietary lectins are metabolic signals for the gut and
modulate immune and hormone functions.
Pusztai A
Rowett Research Institute, Bucksburn, Aberdeen, UK.
Although it is common knowledge that some dietary lectins
can adversely affect the growth and health of young
animals and that, therefore, lectins are implicated in
nutritional disorders of the digestive system, it has not
been rigorously established that findings with animals
are also directly applicable to humans. However,
because the glycosylation state of the human gut is
basically similar to that of higher animals, it may be
confidently predicted that the effects of dietary lectins
will have similarities in both humans and animals. Most
lectins in our diet are resistant to breakdown during gut
passage and are bound and endocytosed by epithelial
cells. These lectins are powerful exogenous growth
factors for the small intestine, can induce dramatic
shifts in its bacterial flora and interfere with its
hormone secretion. In addition, lectins which are
transported across the gut wall into the systemic
circulation can modulate the body's hormone balance,
metabolism and health. Although these physiological
effects are mediated or reinforced by immune responses,
they are primarily the result of the specific chemical
reactivity of lectins with cell surface receptors of the
gut.
Note that there's nothing in here about blood type. But
according to D'Adamo, the "cell surface receptors of the gut" are
also subject to the ABO grouping, so that's the connection. ABO
is not just a blood type; it is a tissue type. Note especially
the importance of the next-to-last sentence.
Here's another one:
Lectins in the US Diet
Am J Clin Nutr 1980 Nov;33(11):2338-2345
Lectins in the United States diet: a survey of lectins in
commonly consumed foods and a review of the literature.
Nachbar MS, Oppenheim JD
Plant lectins or phytohemagglutinins possess potent in
vivo biological activities. Some, primarily of the family
Leguminosae, have been shown to have deleterious
nutritional effects. Little information exists, however,
regarding the prevalence of lectins or the specific foods
that contain lectins in the United States diet. In the
present study the edible parts of 29 of 88 foods tested,
including common salad ingredients, fresh fruits, roasted
nuts, and processed cereals were found to possess
significant lectin-like activity as assessed by
hemagglutination and bacterial agglutination assays.
Based on this survey and a review of the literature we
conclude that dietary exposure to plant lectins is
widespread. The spectrum of nutritional consequences of
such exposure remains to be determined.
This is far from proof that D'Adamo is right, but in conjunction
with the abundant evidence that various diseases are not
distributed randomly across the blood groups, there appears to be
something going on here.
Todd Moody
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