Blood type is a key to unlocking many of the latent healing powers of the body.  It also allows the physician the ability to 'treat the patient, not the disease,' a tenet of healing wisdom as ancient as its source, the great physician Hippocrates.

Type A people had ancestors that were farmers, therefore you should be a vegetarian and avoid meat and dairy products.

Type B had ancestors that were nomads, therefore you should eat red meat and fish.

Type O had ancestors that were hunters and gatherers, therefore you should eat lots of animal protein and little carbohydrates.

Type AB had mixed ancestry, therefore you should eat a combination of Types A and B.

This theory includes a hypothesis on lectins, which claims that they can result in the agglutination of blood cells in an individual with the wrong blood type, and which in turn may create serious liver or kidney problems.

Elevated urine indican levels prevalent in many gastrointestinal diseases such as celiac disease, diverticulitis, pancreatic insufficiency, inflammatory bowel diseases and others can also be attributed to specific blood types affecting the interactions of foods with intestinal bacteria, and creating polyamine abnormalities.

The different blood type diets affect the body's secretory performance in respect to digestive juices, whereby a blood type O for instance is capable of producing higher than average stomach acid levels, which could lead to a greater incidence of gastric ulcers.