There are differing opinions about soy. Personally, I have a BIG problem with it (not psychologically or philosophically, but physically). It is possible to be allergic to beneficial foods, but I think the thing with me is that I am probably a non-secretor (another kind of blood classification) for whom soy is just neutral.
As already mentioned, according to Dr. D, soy is fine for type A and many seem to thrive on it, eating many servings a day.
I do eat some fermented soy products (even all the anti-soy people say fermenting gets rid of most of the negative properties) . . . couldn't live without miso!