A new study carried out by researchers at Harvard TH Chan School of Public Health and Brigham and Women’s Hospital (both MA, USA) has concluded that light and moderate drinking is associated with increased alcohol-related cancer risk in smokers. Light and moderate drinking was defined as up to one drink a day for women and two drinks a day for men.
Heavy alcohol consumption has been linked to increased cancer risk for several years; however, the effects of light to moderate drinking on cancer risk were less clear. The role of alcohol, independent of smoking, in cancer risk is also open for debate.
This study, published recently in The BMJ, demonstrated overall that light to moderate drinking was associated with a minimally increased risk of total cancer in men and women. However, among women, light to moderate drinking was associated with an increased risk of breast cancer regardless of smoking status.
The risk of alcohol-related cancer was higher among light to moderate drinking men, but only in those who had previously smoked. No association was found among men who had never smoked.
The researchers utilized data from two US studies that tracked the health of 88,048 women and 47,881 men for up to 30 years. Total cancer risk was assessed as well as risk of known alcohol-related cancers including colorectal, breast, liver, oral, pharynx, larynx and esophageal cancers. Individual characteristics that could also influence cancer risk, such as age, ethnicity, body mass index, family history of cancer, history of cancer screening, smoking, physical activity and diet were also taken into account.
Light to moderate drinking was defined as 15 g of alcohol or one drink for women and 30 g of alcohol or two standard drinks for men per day. One standard drink is roughly equivalent to a small (118 ml) glass of wine or a 355 ml bottle of beer.
In the follow-up period, 19,269 cancers were diagnosed in women and 7,571 cancers were diagnosed in men. Irrespective of smoking history, light to moderate drinking was associated with a small but nonsignificant increased risk of total cancer.
In an accompanying editorial by Jürgen Rehm from the Centre for Addiction and Mental Health in Toronto (ON, Canada), it is noted that although the current study sheds light on the relationship between light to moderate drinking and cancer, more research is needed to explore the interaction between smoking and drinking on risk of cancer.
Rehm also recommends that people with a family history of cancer: “should consider reducing their intake to below recommended limits or even abstaining altogether, given the now well-established link between moderate drinking and alcohol-related cancers.”