I'm curious, does anyone know of any studies done on different world cultures that might show a direct link between diet, bloodtype and longevity? For example, maybe a predominately "O" type group of people who have been eating foods that are highly beneficial for their blood type for long enough that it might be reflected in a greater longevity rate for them than in other countries where the diets are more diverse? Would this be a way to show how this diet might have been working all along in a historical sense?