British Columbia

Moderate alcohol use increases breast cancer risk, UVic study says

Even moderate drinkers face an elevated risk of developing breast cancer, according to a study from the University of Victoria’s Centre for Addictions Research of B.C.

Alcohol is a known carcinogen, even 1 or 2 drinks a day poses a risk

Red wine is poured from a bottle into a glass.
Even one-glass-a-day drinkers should be aware they are increasing their risk of developing breast cancer, say researchers at the University of Victoria. (Luis Hidalgo/The Associated Press)

Even moderate drinkers face an elevated risk of developing breast cancer, according to a new study from the University of Victoria’s Centre for Addictions Research of B.C. (CARBC).

The study, published in the journal Alcoholism: Clinical and Experimental Research, suggests that consumption levels outlined in Canada’s low-risk drinking guidelines for women still pose a risk.

Dr. Kara Thompson, a research associate at CARBC, said that even one or two drinks a day increases the risk of breast cancer by eight per cent.

"If you're a one-glass-a-day drinker, it's not a huge chance that you're going to get cancer from your drinking, but it does increase your risk," she told CBC News. "When you add other risks — genetic risk and other things — to those, your risk could go up quite substantially."

Researchers reviewed and analyzed 60 studies that were undertaken prior to 2013, many of which had conflicting results about the link between low-dose drinking and breast cancer.

They found that just six of those studies were "free of potentially serious biases," many of which arose because of the way in which drinkers and former drinkers were classified in those studies. 

"When corrected for these biases, the findings confirmed a significantly increased risk for breast cancer from low-dose consumption," the study's authors said.

Though the absolute risk remains small, one of the co-authors, Dr. Tim Stockwell, said the findings should nevertheless encourage caution.

"In general, less drinking means less risk to health," he said.

The Centre for Addictions Research of B.C. estimates that between 250 and 500 Canadian women die of breast cancer linked to their alcohol consumption every year.

With files from the CBC's Lisa Cordasco