The first clear health benefit of wine was that it saved growing populations from the diseases caused by bad water.
Any time large groups of people settle in an area, the water, left untreated, goes bad. People start dying of dysentery, cholera and botulism as more people move in and contaminate the water supply.
Wine doesn't kill you. In fact, the high alcohol content from natural fermentation kills bacteria very efficiently. You can get 15 percent alcohol by volume in your wine without really working at it, and that's a life-saving formula.