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The blood type diet is a diet advocated by Peter D'Adamo and outlined in his book Eat Right 4 Your Type. Its basic premise is that ABO
blood type is the most important factor in determining a healthy diet. The diet is widely
derided by dieticians, physicians, and nutritional scientists as having no scientific basis.[1]
The cornerstone of his theory is D’Adamo’s premise that lectins in foods react differently
with each ABO blood type. Throughout his books he cites the works of various biochemists and glycobiologists who have researched blood groups, claiming or implying that their research supports this
theory. In his book, Eat Right 4 Your Type, “Lectins: The Diet Connection”, and in following chapters, "lectins" which
interact with the different ABO type "antigens" are described as incompatible and harmful, ergo the selection of different
foods for A, AB, B, and O types to minimize reactions with these lectins.
D'Adamo bases his ideas on the ABO classification of Karl Landsteiner and
Jan Janský, and some of the many other tissue surface antigens and classification systems, in
particular the Lewis antigen system for ABH secretor status. [2]
The evolutionary theory of blood groups, which is also used by D'Adamo, stems from work by
William C. Boyd, an immunochemist and blood type anthropologist who made a worldwide survey of the distribution of blood groups. In his book Genetics and
the races of man: An introduction to modern physical anthropology, published in 1950, Boyd describes how by genetic analysis
of blood groups, human races are populations that differ according to their alleles. On this basis, Boyd divided the world population into 13 geographically distinct races with slightly
different frequency distributions of blood group genes.
D'Adamo groups those thirteen races together by ABO blood group, each type within this group having unique dietary
recommendations:
- Blood group O is believed by D'Adamo to be the hunter, the earliest human blood group. The diet recommends that
these supposedly muscular, active people eat a meat-rich diet along the lines of the Paleolithic diet.
- Blood group A is called the cultivator by D'Adamo, who believes it to be a more recently evolved blood type,
dating back from the dawn of agriculture. The diet recommends that individuals of blood group A eat a diet emphasizing vegetables
and free of red meat, a more vegetarian food intake.
- Blood group B is, according to D'Adamo, the nomad, associated with a strong immune system and a flexible
digestive system. The blood type diet claims that people of blood type B are the only ones who can thrive on dairy products.
- Blood group AB, per D'Adamo, the enigma, the most recently evolved type. In
terms of dietary needs, his blood type diet treats this group as an intermediate between blood types A and B.
Criticism
D'Adamo's Blood type diet has met with many criticisms.[3] The fundamental criticisms are first, that none of his hundreds of citations to others' research on
blood groups directly support his claims of differential food tolerances, and second, that he provides no comparative clinical
trials demonstrating efficacy of his diet.[4]
Evidence
One criticism of D'Adamo's hypotheses and recommendations claims that he provided inadequate evidence. For example, his first book, Eat Right 4 Your Type, published in 1997,
contains only a bibliography. Most of his subsequent books, however, have been thoroughly
referenced as far as his general theory. However, the reasons for the classifications of the foods in his diet remain
undocumented.
Although D'Adamo claims there are many ABO specific lectins in foods,[5] this disagrees with the scientific literature. Biochemical research has
found no difference in how the lectins react with any human ABO type. Lectins which are preferential for a particular ABO type
are not found in foods (except for one or two rare exceptions, e.g. lima bean). Lectins with ABO specificity are more frequently
found in non-food plants or animals.[6][7][8]
Another criticism is that there are no clinical trials of the blood type diet. In his first book Eat Right 4 Your Type,
D'Adamo mentions being in the eighth year of a 10 year cancer trial,[9] but no results of this trial have ever been published. In his book Arthritis, Fight it with the
Blood type diet D'Adamo talks about a clinical trial of the Blood Type Diet to determine its effects on the outcomes of
patients with rheumatoid arthritis,[10] but no results of
this trial have been published.
Blood type evolution
In the article "Genetic of the ABO blood system and its link with the immune system",[11] Luiz C. de Mattos and Haroldo W. Moreira point out that D'Adamo's assertion
that the O blood type was the first human blood type requires that the O gene evolved before the A and B genes in the ABO locus.
Instead, phylogenetic networks of human and non-human ABO alleles show that the A gene was the first to evolve.[12] In the evolutionary sense, it would be extraordinary for
normal genes (those for types A and B) to have evolved from abnormal genes (for type O).
Yamamoto et al. further note:
The three most common O genes identified in different populations are O1, O1v (variant) and O2.[13][14][15][16][17] Compared to the ancestral form, the O1 and O1v genes have a deletion of a G base in exon 6 (guanine
in position 261) and show additional nucleotide differences.[18] The O2 gene does not have the G deletion but has a substitution (G802A) in exon 7, which appears to
abolish its function,[19][20] Although the O blood type is common in all populations around the
world,[21] there is no evidence that the O gene
represents the ancestral gene at the ABO locus. Nor is it reasonable to suppose that a defective gene would arise spontaneously
and then evolve into normal genes.
In May 2004, Transfusion[22] published a study which
concluded that: "Assuming constancy of evolutionary rate, diversification of the representative alleles of the three human ABO
lineages (A101, B101, and O02) was estimated at 4.5 to 6 million years ago." This finding indicates that ABO did not evolve in
the near past, as D'Adamo suggests.
Further reading
- D'Adamo, P. (with additional material by Catherine Whitney) (1996). Eat Right 4 your Type. Putnam. ISBN
0-399-14255-X
- D'Adamo, P. (with additional material by Catherine Whitney) (2000). Live Right 4 your Type. Putnam. ISBN
0-399-14673-3
- D'Adamo, P. (with additional material by Catherine Whitney) (2002). The Eat Right 4 Your Type Complete Blood Type
Encyclopedia. Riverhead. ISBN 1-57322-920-2
- D'Adamo, P. "Nontransfusion Significance of ABO and ABO-Associated Polymorphisms" Chapter 43 In: Pizzorno JE, Murray MT
(Eds.) Textbook of Natural Medicine, 3rd Edition, Volume 1 (2006) Elsevier. ISBN 0-443-07300-7 [1]
See also
References
- ^ Blood type diet: Any health benefits? From the Mayo
Clinic website.
- ^ dadamo.com The Individualist
- ^ earthsave.org. Retrieved on August 18, 2006.
- ^ dadamo.com Frequently asserted objections. Accessed August 18,
2006
- ^ D'Adamo, P. (1996). Eat Right 4 your Type. Putnam. ISBN 0-399-14255-X, pg
23, Lectins: the diet connection
- ^ Els J.M. Van Damme, Willy Peumans, Arpad Pusztai, and Susan Bardocz. The
Handbook of Plant Lectins: Properties and Biomedical Applications. New York, John Wiley & Sons, 1998.
- ^ Nachbar MS, and Oppenheim JD."Lectins in the United States diet: a survey
of lectins in commonly consumed foods and a review of the literature".American journal of clinical nutrition, 1980;33:2338.
- ^ Sharon A, Sathyananda N, Shubharani R, Sharuraj M: Agglutination of Human Erythrocytes in
Food and Medicinal Plants, Database of Medicinal Plants, published by the Karnataka State Council for Science and Technology,
May, 2000.
- ^ D'Adamo, P. (1996). Eat Right for your Type. Putnam. ISBN 0-399-14255-X, pg
307, "I am beginning the eighth year of a ten year trial on reproductive cancers, using the Blood Type Diets. My results are
encouraging. So far, the women in my trial have double the survival rate published by the American Cancer Society. By the time I
release the results in another 2 years, I expect to make it scientifically demonstrable that the Blood Type Diet plays a role in
cancer remission."
- ^ D'Adamo, P., Arthritis, Fight it with the Blood type diet (2004) ISBN
0-399-15227-X, pg 300,"IFHI is currently conducting a twelve-week randomized, double-blind, controlled trial implementing the
Blood Type Diet, to determine its effects on the outcomes of patients with rheumatoid arthritis."
- ^ "Genetic of the ABO blood system and its link with the immune system",
Print ISSN 1516-8484, Publication of the Sociedade Brasileira de Hematologia e Hemoterapia, Sociedade Brasileira de Transplante
de Medula Óssea, http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-84842004000100012
- ^ Saitou N, Yamamoto F. Evolution of primate ABO blood group genes and
their homologous genes. Mol Biol Evol 1997; 4(4):399-411.
- ^ Yamamoto F, Clausen H, White T, Marken J, Hakomori S. Molecular genetic
basis of the histo-blood group ABO system. Nature 1990;345:229-233.
- ^ Yamamoto F, McNeill PD, Yamamoto M, Hakomori S, Bromilow IM, Duguid JKM.
Molecular genetic analysis of the ABO blood group system: 4. Another type of O allele. Vox Sang 1993;64:175-178.
- ^ Grunnet N, Steffensen R, Bennett EP et al. Evaluation of histo-blood
group ABO genotyping in a Danish population: frequency of a novel O allele defined as O2. Vox Sang 1994;67:210-5.
- ^ Olsson ML, Chester A. Frequent occurrence of a variant O1 gene at the
blood group ABO locus. Vox Sang 1996;70:26-30.
- ^ Mattos LC, Sanchez FE, Cintra JR et al. Genotipagem do locus ABO (9q34.1)
em doadores de sangue da região noroeste do Estado de São Paulo. Rev Bras Hematol Hemoter 2001;23(1):15-22.
- ^ Olsson ML, Chester A. Frequent occurrence of a variant O1 gene at the
blood group ABO locus. Vox Sang 1996;70:26-30.
- ^ Yamamoto F, McNeill PD, Yamamoto M, Hakomori S, Bromilow IM, Duguid JKM.
Molecular genetic analysis of the ABO blood group system: 4. Another type of O allele. Vox Sang 1993;64:175-178.
- ^ Grunnet N, Steffensen R, Bennett EP et al. Evaluation of histo-blood
group ABO genotyping in a Danish population: frequency of a novel O allele defined as O2. Vox Sang 1994;67:210-5.
- ^ Mourant AE, Kopec AC, Domaniewska-Sobczak K. The distribution of the
human blood groups and others polymorphisms. London: Oxford University Press, 1976. 140p.
- ^ Roubinet F, Despiau S, Calafell F, Jin F, Bertranpetit J, Saitou N,
Blancher A. Evolution of the O alleles of the human ABO blood group gene. Transfusion.2004 May;44(5):707-15
External links
Criticism
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