Women who have a strong family history of breast cancer should avoid drinking alcohol, a new study suggests.
Health experts warn that women whose mothers, grandmothers and aunts have had breast cancer, are more than twice as likely to develop the disease than non-drinkers.
Researchers from the Washington University School of Medicine looked into the role of hormones and body processes in determining certain risks of breast cancer.
The study questioned 9,000 girls aged nine to 15, between 1996 and 2007. Researchers investigated the girls' family history as well as other factors that influence the risk of breast cancer, such as alcohol intake, height and weight, waist circumference and age when they had their first menstrual period.
The study later followed up with the girls in 2003, 2005 and 2007 to see whether any had been diagnosed with breast cancer. Researchers discovered that 67 young women had developed breast cancer between 2005 and 2007.
When alcohol consumption among the female participants was investigated, researchers found that the girls who had relatives with breast cancer, heightened their own risks of developing the disease with the amount of alcohol they drink. The study found that 3.1% of the women diagnosed with benign breast cancer were drinkers, whereas 1.3% were non-drinkers.
"The most common question we hear from women with a family history of breast disease is: 'How can we prevent breast cancer in our daughters?'" says senior study author Dr. Graham Coldtiz. "This points to a strategy to lower risk - or avoid increasing risk - by limiting alcohol intake."
Another author from the study, Catherine Berkley, added, "Families should be aware that drinking alcohol may increase their own risk for (benign breast disease) and for breast cancer later on."
In the UK, 50,000 people are diagnosed with breast cancer - 49,000 of them are women.