A new meta-review of published epidemiological studies supports the association of alcohol consumption with cancer at seven sites in the body. This is, by far, the strongest statement to have been made about the long-recognized association between alcohol and cancer.
The review was published in the journal Addiction by Jennie Connor at the University of Otago in New Zealand. She says that alcohol is estimated to have caused about half a million deaths from cancer in 2012 alone. 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 Bagnardi and colleagues, building on meta-analyses of the effect of alcohol on single cancers.
“There is strong evidence that alcohol causes cancer at seven sites in the body and probably others,” says Connor. “Current estimates suggest that alcohol-attributable cancers at these sites make up 5.8% of all cancer deaths world-wide. Confirmation of specific biological mechanisms by which alcohol increases the incidence of each type of cancer is not required to infer that alcohol is a cause.”
Even without complete knowledge of biological mechanisms, the epidemiological evidence can support the judgement that alcohol causes cancer of the oropharynx, larynx, oesophagus, liver, colon, rectum and breast. 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 measured associations exhibit gradients of effect that are biologically plausible, and there is some evidence of reversibility of risk in laryngeal, pharyngeal and liver cancers when consumption ceases,” Connor mentions in her review.
The review found endorsement from a lot of health experts. They insist that the results indicate that the government should initiate more education campaigns to tackle the public’s ignorance regarding the association between alcohol and cancer. Calls for alcohol packaging to carry warnings and organizing alcohol-free days were renewed, as well.
Dr Jana Witt, Cancer Research UK’s health information officer, said: “We know that nine in 10 people aren’t aware of the link between alcohol and cancer. And this review is a stark reminder that there’s strong evidence linking the two.” She continues, ““Having some alcohol-free days each week is a good way to cut down on the amount you’re drinking. Also, try swapping every other alcoholic drink for a soft drink, choosing smaller servings or less alcoholic versions of drinks, and not keeping a stock of booze at home.”
The road ahead to convince the people, however, is convoluted and an uphill task, warns Connor. “There will be orchestrated attempts to discredit the science and the researchers, and to confuse the public. The stakes are high for alcohol industries when there is no argument, on current evidence, for a safe level of drinking with respect to cancer.”
So, put down that drink! Even moderate amounts is capable of putting you at risk of cancer.