A study has revealed that alcohol consumption before first pregnancy is consistently associated with increased risks of proliferative benign breast diseases (BBD) and breast cancer.

Researchers from the Washington University School of Medicine in St Louis found that the more alcohol a woman drinks between her first period and her first full-term pregnancy, the higher her risk of developing breast cancer.

The study dubbed: “Alcohol intake between menarche and first pregnancy: A prospective study of breast cancer risk,” published in the Journal of the National Cancer Institute, was made available to the Ghana News Agency on Tuesday.

The study used data from 91,005 women in the Nurses’ Health Study II who had no cancer history, completed questions on early alcohol consumption in 1989, and were followed through June 30, 2009, to analyse breast cancer risk.

A subset of 60,093 women who had no history of BBD or cancer in 1991 and were followed through June 30, 2001, were included in the analysis.

The study identified 1,609 breast cancer cases and 970 proliferative BBD cases confirmed by central histology review.

The study shows that if a female averages a drink per day between her first period and her first full-term pregnancy, she increases her risk of breast cancer by 13 per cent, in addition to breast cancer.

The researchers found that a daily drink increases the risk of proliferative benign breast disease by 15 per cent.

Although this was an observational study, the researchers did note that breast cells rapidly proliferate during adolescence and may make them even more susceptible at this time to carcinogens.

It noted that the association between drinking before first pregnancy and breast formation of new tissue appeared to be stronger with longer first menstrual cycle to first pregnancy intervals.