Earlier quoted context omitted.
> It showed a Indians in a tiny village who were falling ill because they were literally taking a shit in the same river that they were getting their drinking water from, just a few meters away. Many things that are obvious to now are not obvious unless we are rightly educated. You might like to read http://www.npr.org/sections/health-shots/2015/01/12/37566392... which believe it or not is not even 150 years old.
Sure, but non-obvious things often manifest in culture nonetheless. For example the romans with their mighty aqueducts, cleanliness rules in religion, drinking tea (needs boiled water) or beer/wine (alcohol desinfects), or being obsessed that evil witches dont poison your wells etc.
Also, beer provides large amounts of calories, so it also feeds the consumer with low risk of the "food" getting stale. There's a reason why in Bavaria a fat belly is called a "Bierbauch" ;)