Light to moderate drinking -- or about one drink per day -- was associated with a 13 percent increase in alcohol-related cancers in women, according to a study published in the British Medical Journal in August. The elevated risk for cancer was mainly driven by breast cancer, although breast cancer was not the primary focus of the study.
The breast cancer risk among moderate drinkers -- compared to those who don't drink -- is "modest but statistically significant," Yin Cao, the lead author on the study and a research fellow in the nutrition department at Harvard's T. H. Chan School of Public Health, told The Huffington Post.
"For women, we did not observe increased risk for alcohol-related cancers among light to moderate drinkers if breast cancers were not included," he said.
The researchers found no significant association between men who drank moderately -- defined as two drinks per day -- and an increased risk of cancer, unless the man was a current or former smoker. Heavy drinkers of both sexes who also smoked had a greater risk of alcohol-related cancers than heavy drinkers who had never smoked.
The new findings contradict previous research that linked alcohol intake to a swath of cancers, including pancreatic, lung, colon, oral, throat and liver cancers, so more research is necessary to explore the relationship. Alcohol consumption accounts for almost 4 percent of cancer deaths in the United States, according to the American Journal of Public Health.
The new study used data from two large cohort studies in the United States: the 1980 Nurses' Health Study and the Health Professionals Follow-Up Study, which started in 1986 and ran until 2010.
As the researchers noted, the study should be considered with caveats. "Decisions on levels of alcohol consumption should also take into account history of smoking, family history of alcohol-related cancers, and risk profile for cardiovascular diseases," Cao said. Moderate drinking -- one drink per day for women or two drinks per day for men -- is associated with cardiovascular benefits, according to the Mayo Clinic.
"Specifically for women, the potential modest elevated risk of alcohol-related cancers, primarily breast cancer, should also weigh against potential benefits on cardiovascular diseases," Cao said, noting that in general, the study reinforces dietary guidelines that recommend limited alcohol consumption.
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