I've been told that for most of history, water was not considered drinkable and that many cultures preferred to drink mild alcoholic drinks because the acidity brought on during fermentation kept it sterile (Posca in the mediterranean, hopped beer in northern europe, etc). Some cultures today still believe that cold water is unhealthy or that water as a whole is linked to diseases such as tuberculosis.
This seems to have changed over the past century in the West, so I'm curious:
Were there any older cultures or periods in history where pure water drinking was considered healthy?
how did cultures with religious or social prescriptions against alcohol keep their water sanitary?
In cultures that today now consider water healthy, when and how did that shift occur? What groups encouraged the transition?
edit: Century, not decade.
Were there any older cultures or periods in history where pure water drinking was considered healthy?
Yes. All of them.
One of the biggest myths in popular history was that people had problematic access to water before modern times. My research has failed to find a single primary source that backs up this contention. To do the contrary the written record show numerous examples of people drinking water. People drank from streams, rivers, wells and springs. In populated cities (which were very rare) they would engineer public works to bring in fresh water if the local sources were unsafe.
When a specific source of water was bad from human contamination people recognized it and just didn't drink it and there were many rules/laws to keep people from polluting water soruces.
As for the source of this myth I just think this one of those things that many "pop history" writers repeat because everyone else does. No one ever cites a source. My instincts make me wonder if maybe this dynamic existed for a for a very brief time during the cholera outbreak in London in the late 19th century. That;s my next target of investigation, but even if it existed there its clearly not a systemic pattern throughout history.