Using data from the long-running Framingham epidemiological study, in which 287 women out of about 5,000 developed breast cancer, researchers compared women who abstained from alcohol with those who did drink. The results were published in the Jan. 15, 1999, issue of the American Journal of Epidemiology.
The drinkers did not show increased rates of breast cancer, whether the women averaged less than half a drink a day or more than a drink and a half daily. Nor was higher risk associated with wine, beer or spirits when these categories were assessed separately.
"The present results are important since they apply to the vast majority of women drinkers in the United States--most of whom average less than one drink per day," stated Dr. R. Curtis Ellison, chief of Boston University's preventive medicine and epidemiology section. "For these women, the results of this study are reassuring."
While medical research has shown that moderate alcohol consumption can reduce the risk of heart disease, the benefits have been less clear for women. Many earlier studies have found that breast cancer rates are higher among heavy drinkers, and some studies indicated that the risk begins to rise with one drink per day.
Yuqing Zhang, lead author of the study and assistant professor of medicine and epidemiology, indicated that the Framingham study cannot assess the effect of heavy alcohol consumption on breast cancer risk because few women in the study consumed two or more alcoholic beverages a day.