A recent study found that: Women of normal weight who drank a moderate amount of alcohol — especially red wine — were less likely to gain weight than women who didn’t drink at all.

The researchers caution that alcohol can have harmful effects, but weight gain among light drinkers may not be one of them.

Scientists have long noted the apparently beneficial association of red wine with good heart health among French people who ate rich diets, called the French paradox, but there have been conflicting reports on alcohol and weight gain.

Dr. Lu Wang of Brigham and Women’s Hospital and her colleagues followed almost 20,000 healthy women age 38 or older who answered questions annually about their weight and alcohol consumption. After almost 13 years, 41 percent of the women became overweight and 4 percent became obese. Women who did not drink gained the most weight. The amount of weight gained slid lower as the amount of alcohol consumed climbed.

Compared with nondrinkers, women who drank 15 grams to 29 grams of alcohol a day — the amount found in one to two drinks — had a 30 percent lower risk of becoming overweight, with red wine accounting for the strongest association. The risk of becoming overweight did not go down further when the women drank more than 40 grams of alcohol a day.

BOTTOM LINE: Middle-aged women of normal weight who were light drinkers gained less weight than nondrinkers after 13 years.

CAUTIONS: The study did not show that drinking caused the decline in weight gain, and the findings do not apply to men. Unknown differences between women who drink moderately and those who don’t could explain the findings, even though the researchers tried to account for other factors.