Blood type group systems, 308 different blood-group antigens have been found. Almost always, an individual has the same blood group for life, but very rarely an individual's blood type changes through addition or suppression of an antigen in infection, malignancy, or autoimmune disease. Another more common cause in blood type change is a bone marrow transplant. Bone-marrow transplants are performed for many leukemias and lymphomas, among other diseases. If a person receives bone marrow from someone who is a different ABO type (e.g., a type A patient receives a type O bone marrow), the patient's blood type will eventually convert to the
Blood type diet Blood type diet The blood type diets are fad diets advocated by several authors, the most prominent of whom is Peter J. D'Adamo. These diets are based on the notion that blood type, according to the ABO blood group system, is the most important factor in determining a healthy diet, and each author recommends a distinct diet for each blood type. The consensus among dietitians, physicians, and scientists is that these diets are unsupported by scientific evidence. In what was apparently the first study testing whether there was any benefit to eating the "right" diet according to one's blood type,