Alcohol and breast cancer

The relationship between alcohol and breast cancer is clear: drinking alcoholic beverages, including wine, beer, or liquor, is a risk factor for breast cancer, as well as some other forms of cancer.^[1][2][3][4] Drinking alcohol causes more than 100,000 cases of breast cancer worldwide every year.^[3] Globally, almost one in 10 cases of breast cancer is caused by women drinking alcoholic beverages.^[3] Drinking alcoholic beverages is among the most common modifiable risk factors.^[5]

The International Agency for Research on Cancer has declared that there is sufficient scientific evidence to classify alcoholic beverages a Group 1 carcinogen that causes breast cancer in women.^[2] Group 1 carcinogens are the substances with the clearest scientific evidence that they cause cancer, such as smoking tobacco.

A woman drinking an average of two units of alcohol per day has 13% higher risk of developing breast cancer than a woman who drinks an average of one unit of alcohol per day.^[6] Even light consumption of alcohol – one to three drinks per week – increases the risk of breast cancer.^[3]

Heavy drinkers are also more likely to die from breast cancer than non-drinkers and light drinkers.^[3][7] Also, the more alcohol a woman consumes, the more likely she is to be diagnosed with a recurrence after initial treatment.^[7]