Light or moderate drinking is linked to alcohol related cancers, including breast cancer

Using data from two large cohort studies in the United States, Cao and colleagues1 examine the question of whether light to moderate drinking is associated with an increased risk of cancer. This question is important for a variety of reasons related to public health and alcohol policy. Cancer is one of the major causes of death globally,2 and cancer risks are frequently cited in arguments about formulating thresholds for low risk drinking guidelines.3 For instance, when Canadian guidelines were reformulated recently in 2011, in part based on the argument that consumers would not accept strict guidelines, cancer risk at low doses of alcohol use was introduced into the public health debate.4

Cao and colleagues found that in women, light to moderate drinking was associated with an increased risk of cancers with an established link to alcohol consumption—that is, cancer of the colorectum, female breast, oral cavity, pharynx, larynx, liver, and oesophagus.5 The increased risk was driven mainly by breast cancer. Similar findings emerged for light to moderate male drinkers who had ever smoked. No significant association was found in men who never smoked, or in women outside the relation with breast cancer. Also, no association was found …