Thanks for your response, razzle. I also think it makes sense that certain groups have developed "digestive goodies" to deal with certain foods. It would be interesting to study -- and very difficult because, of course, if you took any ethnic/national group there would be -- as was pointed out -- lots of differences within the group. It would involve tracing individual histories -- and many of us probably don't have a very good idea of who our great-grandparents were, or when the family made the move from countryside to city, seaside to mountain, etc. I'm firmly convinced that individual genetics is so refined that there's an olive gene -- olives are an "acquired taste" only for those who don't have it. The longer an ethnic group has been isolated, I would reason the stronger the food preferences/tolerances is.