Drinking alcohol ups your risk of cancer—several kinds of cancer, in fact. The links have been firmly established and reaffirmed over the years with stacks of studies, reviews, and meta-analyses. The National Cancer Institute has had an explainer on the subject since at least 2013.
Yet, the connection remains relatively unknown to consumers.
“We know that nine in 10 people aren’t aware of the link between alcohol and cancer,” Jana Witt, Cancer Research UK’s health information officer, told The Guardian. And the few that are aware of the link may be skeptical of it based on misleading health stories and competing reports on the potential benefits of drinking.
This confusion, ignorance, and skepticism frustrated Jennie Connor, a preventive and social medicine expert at Otago University in New Zealand. So, she tried to clear up the public health facts with an opinion piece published Thursday in the journal Addiction, under the section “For Debate.” Her piece offered the declarative perspective that alcohol causes cancer.
But, it seems the message got even more muddled.
Dozens of news headlines and reports blared that her new “study” found that alcohol causes cancer, suggesting not only that her conclusion was new, but that Connor herself had reported fresh, objective data and/or analysis supporting the finding—neither of which is true. One reporteven called her opinion piece a meta-analysis, others suggested that Connor had multiplied, referring to her as “researchers.”
While these errors may appear minor to some, confusing an opinion piece with research is likely to seem disturbing, if not egregious, to those in the scientific community. After all, scientific endeavor is rooted in empiricism and objectivity. And that’s not to mention the problem of potentially passing off years of research as one person’s conclusion, arrived at in a brisk seven-page article with zero data or analyses.
In her opinion piece, Conner quickly outlines the established link between drinking alcohol and several types of cancers, namely those of the “oropharynx, larynx, esophagus, liver, colon, rectum, and female breast.” The increase in relative risks of getting these cancers varies depending on how much alcohol a person drinks—the more alcohol, the higher the risk, generally—plus that person’s genetics. In many cases, however, the absolute risks are still small. She also briefly references studies that suggest that alcohol may contribute to cancers of the pancreas, prostate, and skin.
Conner argues that the studies that found links and correlations between drinking and cancer—studies that largely involve observations about populations or groups of people—can be enough to make a judgment on causation. Scientists can safely make such judgments if the studies have features such as “strength, consistency, specificity, temporality, biological gradient, plausibility, coherence, experimental evidence, and analogy,” she reasons. After weighing all the studies on alcohol’s association with cancer, Conner believes that causation is clear.
She goes on, however, to knock back links suggesting that drinking may lower a person’s risks of cardiovascular disease (CVD), noting that people who drink moderately also tend to have other lifestyle factors that lower their disease risk. Or, put another way, she noted that “in a large US survey in 2005, 27 of 30 CVD risk factors were shown to be more prevalent in abstainers than moderate drinkers.”
While Connor’s “study” is in fact a well-referenced opinion piece, other researchers say she’s on the right path. Alan Boobis, professor of biochemical pharmacology at Imperial College London, toldThe Guardian that alcohol’s role in cancer has been well established. “The main difficulty,” he explained “is communicating effectively with the public.”