according to your logic then all white people should die if they drink mexician water. that is so far from the truth it is laughable. there are many many white people especially missionaries who, over time, can adapt to it. now if they drink tons of it all at once, then yes they will get violently ill. but if its done little by little, how you say, "woohoo" they are okay and can slowly drink more and more. That is adapting which happens with every living thing slowly over time. The best is if you start when your young. you take a frog and every 10th feeding add a market bought local fish, then every 9th then 8th and so on. same with everything else. if you use only healthy wild animals this risk becomes less and less. then WOOHOO you have a old frog that is not only healthy but almost indestructible to anything. The risk is in fact low and will become lower and lower over time just like when any new culture moves to a different land. some cant handle to total sumergion into foreign areas but most do. you have not taken "adaptation" into your equation and might want to look into what i am doing in a different way to understand it fully.
thanks for the info, i really like the woohoo. (: