A new study has found that alcohol, consumed even in small amounts, boosts the risk of breast cancer, particularly estrogen-receptor and progesterone-receptor positive breast cancer.
The study led by Jasmine Lew, from the National Cancer Institute (NCI) in America has revealed that alcohol is the substantial risk factor for development of the most common type of breast cancer.
For the study, the team examined 184,418 postmenopausal women who enrolled in this cohort study, and were asked to tell their daily alcohol consumption.
During an average of seven years of follow-up, they found that 70 percent of women in the study drank alcohol; the average amount was a little less than a drink a day. Overall, the authors found that moderate drinking in women increased risk of developing breast cancer.
"Our study shows that not only does a small amount of alcohol significantly increase the risk of breast cancer, it increases the risk of the most common type of breast cancer, responsible for round 70 per cent of cases," Lew said.
"This suggests that a woman should evaluate consumption of alcohol along with other known breast cancer risk factors, such as use of hormone replacement therapy," she added.
The findings revealed that women who consumed less than one drink daily, one to two drinks, and three or more daily drinks relatively increased the risk of developing breast cancer by 7 percent, 32 percent, and 51 percent, respectively.
"There is a large body of research which shows that alcohol can cause breast cancer, probably by increasing levels of the hormone oestrogen," said Dr Joanna Owens, a science information officer at Cancer Research UK.
"This new research supports these conclusions and shows that drinking just two units a day can increase the risk of developing the disease," she added.