Could a daily wine habit prevent weight gain? Yes, according to a new study by experts at Brigham and Women's Hospital in Boston, suggesting that women who drink a moderate amount of alcohol daily—especially red wine—are less likely to pack on the pounds in midlife than women who drink occasionally, or don't drink at all. (Watch a CBS report about the wine study.) The study, which followed 20,000 women over a period of 13 years, represents some of the most comprehensive findings on the impact of alcohol on weight. Here, a look at the evidence for the "new wine paradox":
Is wine the only 'slimming alcohol'? No, but it seems to be the most beneficial one. Though researchers found that women who drink any type of alcohol in moderation tend to be slimmer than nondrinkers—they found the strongest association between relative slenderness and vino consumption.

What's a 'moderate' amount of wine? A lot less than you probably think. The study defined "moderate" as one 125-calorie, 5-ounce serving daily—about half what you'll find in a single typical restaurant pour. (See a CBS Early Show story comparing serving sizes.)

How much lighter than average were the wine-drinkers? The imbibers managed to maintain a weight that was, on average, around 4.5 lbs less than the nondrinkers'—statistically significant, but not noteworthy enough, it seems, for wine manufacturers to start touting vino as the newest diet craze. Somewhat confusingly, the more the women drank, the slimmer they stayed—a "curious" finding that researchers say warrants "further investigation."
Why do researchers think wine keeps women slim? They're not entirely sure, but plenty of theories are being floated, ranging from the obvious—the notion that wine drinkers find "liquid dinners" sufficiently satisfying, ultimately ingesting fewer calories—to the intriguing: Resveratrol, a chemical compound found in grape skins and renowned for its anti-aging properties, might also have "anti-obesity properties."

Were results similar with male research subjects? It doesn't look like it. While this study focused on women, other studies show that male drinkers pack on the pounds just as quickly as their nondrinking counterparts. Some scientists hypothesize that, unlike women, men drink alcohol on top of their daily food intake, while others believe that men metabolize booze differently.

Does moderate alcohol consumption have other health benefits? Other studies have suggested that a light drinking habit helps the heart, reduces the risk of age-related mental illness like dementia, and may even reduce the likelihood of depression.

But surely women shouldn't start drinking to stay slim? This is a study, not advice. "If the message is that by drinking some alcohol you're going to lose weight, that's a potentially complicated and dangerous message," warns Dr. James C. Garbutt, a professor of psychiatry at the University of North Carolina's Bowles Center for Alcohol Studies, as quoted in the Los Angeles Times.