Women drinking just three to six glasses of alcoholic beverages per week face a small increase in their risk of developing breast cancer, according to new research.
The US research, published today in the Journal of the American Medical Association, drew on a health study of 105,986 nurses, 7690 of whom developed invasive breast cancer.
Analyses of data indicated that a low level of alcohol consumption (equivalent to three to six glasses of wine per week) was modestly but statistically significantly associated with a 15 per cent increased risk of breast cancer. In addition, women who consumed at least two drinks per day) had a 51 per cent increased risk of breast cancer compared with women who never consumed alcohol.
The authors add that although the exact mechanism for the association between alcohol consumption and breast cancer is not known, one probable explanation may involve alcohol’s effects on circulating estrogen levels.
However, Jake Najman, Professor of Population Health at the University of Queensland and Director of the Queensland Alcohol and Drug Research and Education Centre, said that the findings should be seen in perspective.
“The level of increased risk with small quantities of alcohol is small, and the paper doesn’t comment on changes in the risk of death from all causes,” Professor Najman said.
An equivalent UK study “suggests a decline in overall death with low levels of alcohol consumption, so yes there is an increased risk of breast cancer but a decrease from cardiovascular disease,” Professor Najman said.
The report’s authors write that dietary factors other than alcohol probably contribute to the risk of developing cancer, and they point out that for some women, drinking alcohol might be a healthy choice.
“An individual will need to weigh the modest risks of light to moderate alcohol use on breast cancer development against the beneficial effects on cardiovascular disease to make the best personal choice regarding alcohol consumption,” they write.
Professor Najman concurred: “for most women, the best advice might be to have a glass a night. Age might matter; female rates of heart disease increase rapidly after the menopause.”