> > Except that most of human evolution occurred somewhere in Africa, and > > many plants we currently eat originate from Europe, Asia or America. Carol: > Is the biochemistry of the plants of Africa so startlingly different > from that of the plants of Europe, Asia or America? "Startingly different", I don't know, and I don't think it is, but that's not the point. Two different plants (whether from the same continent or not) produce different proteins (or whatever chemicals). Some may be allergenic or carcinogenic. Since humans have not been in contact with plants from, say, America, until recently, they can't possibly have adapted to every allergen or carcinogen in American edible plants. Even if they were very close to African plants on the biochemistry viewpoint, just one "new" protein could be enough. Also, we should keep in mind that genetic adaptation is never "perfect". --Jean-Louis Tu <[log in to unmask]>