A new study suggests that teenage girls and young women with a family history of breast cancer should steer clear of alcohol. The study found those who had a drink a day on average were more than twice as likely as those who didn’t drink to develop benign breast disease, a risk factor for breast cancer.

Benign breast disease is lumpy breast tissue, which in a small percentage of cases could develop into breast cancer, Reuters reports. The researchers, from Brigham and Women’s Hospital in Boston, followed almost 7,000 girls ages nine to 15, from 1996 to 2007. Seventeen percent of the girls had a mother, aunt or grandmother with breast cancer. At the end of the study, among girls who had about a drink a day, 3.1 percent had developed benign breast disease, compared with 1.3 percent of those who didn’t drink.

The study does not prove that alcohol caused the breast disease, the article points out. The results are published in the journal Cancer.

“It is mostly an interesting observation, but it is going to have a very limited public health impact,” Dr. Steven Narod, who heads the Familial Breast Cancer Research Unit at Women’s College Hospital Research Institute in Toronto, and was not involved with the study, told Reuters.

Earlier this month, a study in the Journal of the American Medical Association found women who have three to six alcoholic drinks a week are at slightly increased risk of developing breast cancer compared with women who don’t drink at all.

The study followed more than 100,000 nurses for up to almost 30 years. The women in the study who had three to six drinks a week had a 15 percent increased risk of developing breast cancer compared with nondrinkers. That translates into about four additional cases of breast cancer per 1,000 women. A woman’s risk of the disease increased the more she drank, regardless of whether she drank wine, beer or liquor.