Cocktails ward off the bulge

Large study links light to moderate drinking with less weight gain in middle-aged women

Cocktail chatter just got a little more interesting. Women who drink in moderation are more likely to keep the pounds at bay than their teetotaler counterparts, finds a study published March 8 in the Archives of Internal Medicine.

Because many alcoholic drinks are high in calories, drinking more might seem like a surefire way to gain weight. But researchers led by Lu Wang of Brigham and Women’s Hospital in Boston found the opposite — at least among healthy, middle-aged women working in health care professions. 

The study examined the habits of 19,220 American women over age 38. All of the women began the study at a normal weight, but after almost 13 years about 41 percent of the women were overweight or obese. Women who reported drinking no alcohol — 38 percent of the entire sample — gained the most weight. A statistical analysis showed that women who did not drink could expect to gain 3.45 to 3.80 kg during the 13-year study. In contrast, women who drank moderately — about one to two glasses of wine a day — could expect to gain between 2.13 and 2.99 kg.

The trend held true up through moderate drinking levels, but researchers didn’t have enough heavy drinkers in their sample group to analyze. Only 3 percent of their sample group reported drinking two to three drinks per day or more.

The type of alcohol didn’t much matter, Wang says. Red wine, white wine, beer and liquor all showed the same trend. 

Wang and her colleagues can’t explain the results, but the team has found that women who drink moderately actually consume fewer total calories on average than those who don’t drink, offsetting their alcohol intake through lower consumption of other foods. Women of normal weight also tend to burn more calories after drinking alcohol than the alcohol itself provides. There is also some evidence that alcohol may affect metabolic processes, leading to differences in weight gain.  

Thomas Greenfield, director of the Alcohol Research Group in Emeryville, Calif., says the new study is “thoroughly presented,” but he would have liked a more detailed assessment of alcohol consumption. At the beginning of the study, women reported how much alcohol they had consumed in the past year, with nine choices ranging from “never or less than once per month” to “6+ per day.” Participants often underestimate the amount of alcohol they consume, he says. What’s more, alcohol’s effects might be different for someone who has a glass of wine every night compared to someone who has seven drinks every Saturday night. “It is an imperfect measure,” he says, “but the results are nonetheless plausible in my view.”

Wang cautions that because the study was conducted on healthy, normal-weight women, the results don’t apply to women who are already overweight or obese. “Our results suggest that healthy women can keep their drinking habits,” she says. “It’s different from when you’re already obese and looking for ways to lose weight.” Nor do the results suggest that heavy drinking might be beneficial. “Keep the amount moderate, don’t forget to eat healthily and exercise,” she says.

Laura Sanders is the neuroscience writer. She holds a Ph.D. in molecular biology from the University of Southern California.

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