Technically, there's no category called "low-alcohol wines." Most white wine hovers around 11 percent alcohol, and most red is in the 13 percent range. Lately, California has been churning out big, bruising, expensive red zinfandels with 15 percent and more, and the wine-selling and wine-buying communities have come to equate high alcohol with high quality.
Although the difference in alcohol between different wines may be only two or three percentage points, it makes a big difference in context. If a light Italian pinot grigio comes in at 11 percent, a glass of one of those scary zins at 15 percent will get you almost 1.5 times as intoxicated, which is profound, especially if you think you're just going to have a glass or two. On the other hand, a Portuguese Vinho Verde with seven or eight percent delivers 40% less active ingredient, and that's welcome on a steamy summer day. Tastes great versus less intoxicating: you make the call.