Evidence Mounting That Moderate Drinking Is HealthfulBy ABIGAIL ZUGER any drugs can save your life or kill you, depending on how much of them you take. Only one comes on the rocks with a twist, in a chilled mug with a foamy head, or in a goblet with lingering overtones of raspberry and oak.Alcohol has become the sharpest double-edged sword in medicine.Thirty years of research has convinced many experts of the health benefits of moderate drinking for some people. A drink or two a day of wine, beer or liquor is, experts say, often the single best nonprescription way to...