General Discussion
In reply to the discussion: Modern wheat a "perfect, chronic poison," doctor says [View all]DhhD
(4,695 posts)antigens against mostly wheat and corn and some against oats and rice. Type OO is the most frequent blood type in the human population. Some study on movement of people into and out of Europe will help one understand where the A and B blood antigens originated and why. For instance, blood type B developed in areas where humans mainly had animals for food. And they have no antigen (allergic reaction) against bovine milk.
Blood and its cells/contents move food from the alimentary canal/gut to the cells of the body. The gut has many surface capillaries in the intestines so a reactions can get started before absorption in to the capillaries.
There are numerous other factors in each person's body as to allergic reactions. Blood type is a big one though.