Alcohol consumption may cause seven types of cancer, including that of oesophagus, liver, colon and breasts, even in moderate drinkers, new research has warned.
A review of epidemiological evidence found that alcohol caused about half a million deaths from cancer in 2012, 5.8 per cent of cancer deaths worldwide, researchers said.
The highest risks are associated with the heaviest drinking, but a considerable burden is experienced by drinkers with low to moderate consumption.
The researchers from University of Otago in New Zealand also found the current evidence that moderate drinking provides protection against cardiovascular disease is not strong.
The review showed that alcohol consumption directly causes cancer at seven sites in the body: oropharynx, larynx, oesophagus, liver, colon, rectum and breasts.
The causal link was supported by evidence for a dose-response relationship, at least partial reversal of risk when alcohol consumption is reduced, statistical adjustment for other factors that might explain the association and specificity of the association with some cancers and not others.
The epidemiological evidence for these conclusions comes from comprehensive reviews undertaken in the last 10 years by the World Cancer Research Fund and American Institute for Cancer Research, the International Agency for Research on Cancer, the Global Burden of Disease Alcohol Group, and the most recent comprehensive meta-analysis undertaken by researchers at University of Otago, building on meta-analyses of the effect of alcohol on single cancers.
The research was published in the journal Addiction.