Blood type diet type diet hypothesis and no clinical evidence that it improves health. Peter J. D'Adamo, a naturopath, is the most prominent proponent of blood type diets. Luiz C. de Mattos and Haroldo W. Moreira point out that assertions made by proponents of blood type diets that the O blood type was the first human blood type requires that the O gene have evolved before the A and B genes in the ABO locus; phylogenetic networks of human and non-human ABO alleles show that the A gene was the first to evolve. They argue that it would be extraordinary, from the perspective
Jehovah's Witnesses and blood transfusions was released, outlining Jehovah's Witnesses' general doctrine on blood. In 2000, the Watch Tower Society's stand on blood fractions was clearly stated. Members were instructed to personally decide if accepting a fraction would violate the doctrine on blood. In a later article, members were reminded that Jehovah's Witnesses do not donate blood or store their own blood prior to surgery. In May 2001, the Watch Tower Society revised its medical directives and identity cards addressing its doctrinal position on blood; the revised materials were distributed from May 3, 2001. These revised documents specified that "allogeneic blood transfusions" were unacceptable whereas