Even more troubling was the over-simplified way the study was explained in various news reports, making some women think that just having a mojito with the girls could give them cancer.
New York University cardiologist Nieca Goldberg, who hosts a weekly "ask the doctor" call-in show on SiriusXM Radio, says she got calls from worried women asking, "What's going to happen to me? Am I going to get breast cancer?"
"But you can't just go by a headline. This needs to be put into perspective," she says.
The study looked at the cumulative effect of low to moderate alcohol consumption among more than 100,000 women, ages 30 to 55.
Although previous studies had shown a link between alcohol consumption and breast cancer risk, the emphasis had been on binge or heavy drinking. This study, published this month in the Journal of the American Medical Association, looked at the cumulative effect over a woman's lifetime of drinking low to moderate amounts of alcohol.
The researchers found that those who drank as few as three to six alcoholic drinks a week during those years had a 15 percent increased risk of breast cancer, compared with those who didn't drink. Women who regularly drank two or more drinks a day had a 51 percent higher risk than women who never drank.
Those numbers — 15 percent increase and 51 percent increase — sound high until you do the math.
The average woman's risk of getting breast cancer in her lifetime is one in eight, or 12 percent. A 15 percent increase over that means her lifetime risk rises to 13.8 percent.
Even the study's authors point out in their conclusion: "We did find increased risk at low levels of [alcohol consumption], but the risk was quite small."
In an editorial accompanying the study, Steven A. Narod, M.D., director of familial breast cancer research at the Women's College Research Institute in Toronto, further clarified the findings by explaining that, women who drank two or more drinks a day saw their 10-year risk increase from 2.8 percent to 4.1 percent.
Given that these are fairly small increases, Narod thinks it raises the question: "Should postmenopausal women stop drinking to reduce their risk of breast cancer?"
Some women, especially those with other risk factors like a family history of breast cancer or a genetic marker like the BRCA gene, may decide it's prudent to stop drinking.
For a woman without high risk factors, "if she is a moderate drinker, I don't think she needs to stop," he told the Bulletin.