I'm writing a paper comparing the ritual purity practices of Hinduism and Judaism and it's interesting in the middle ages that many of the diseases had not effected the Jewish population in Europe. This led to speculation that the Jews were poisoning the wells. A logical fallacy is even named the fallacy of poisoning the well. A lot of the diseases came from pork products at the time, the spanish flu of 1918 was also from pork, and scholars now think the Jews avoided the diseases because they avoided pork. Nowadays chicken and other poultry are to blame for a lot of the flu cases. I'm sure the hygiene practiced by the Jews in the middle ages helped as well though. As far as diet I like the idea of staying on the perimeter of the grocery store and avoiding the center. And I think avoiding certain kinds of meat helps as well. I try to consume organic free range meats and try to eat meat no more than once a day when possible. I read an article recently on MSN about the increasing contamination of the meats in this country.