The new research, connecting alcohol consumption to various types of cancer, comes from Professor Jennie Connor, based at the University of Otago in New Zealand. Professor Connor’s research indicates that alcohol has led to some half a million deaths from cancer in 2012 (which relates to the most recent data available.) This represents 5.8 percent of all cancer deaths worldwide.
Moreover, these alcohol-cancer deaths are not simply liver cancer (which has long been the cancer associated with alcohol abuse), but also cancers of the mouth and throat, larynx, esophagus, liver, colon, bowel and breast. While most of these cancers present a risk in relation to those who drink heavily, even low level drinking presents a risk, according to Professor Connor.
The research is a meta-study, where the results of other studies have been compiled and analyzed (in this case, over a 10-year period.) Professor Connor thinks the outcome of the data review (of biological and epidemiological research) is more than a statistical bias towards an elevated cancer risk. She told The Guardian: “Even without complete knowledge of biological mechanisms [of how alcohol causes cancer], the epidemiological evidence can support the judgment that alcohol causes cancer.”
Connor’s research showed that heavy drinkers were at greater risk, although low-to-moderate drinkers were still at risk (this is what is called “a dose-response relationship.”) This surprised some social media users (Luma Diab
@EngrLumaD tweeting: “Drinking, even in lower levels, causes high risks of different cancers”; see also various related tweets under ‘cancer / alcohol’.)
More positive news was the finding that drinkers who gave up alcohol could reverse the risk of developing certain types of cancer: laryngeal, pharyngeal and liver cancer; here the risk reduced the longer someone avoided alcohol.
Commenting on the research, in an interview with New Scientist magazine,Susannah Brown, who is the science program manager for the World Cancer Research Fund, said: “We see the risk increasing as the amount of alcohol consumed increases, and we agree that there is solid evidence to conclude that alcohol consumption directly causes cancer.”
How accurate is the new research and to what extent should you be worried? It certainly tallies with a statement issued from the U.K.’s chief medical officers, who earlier in 2016 stated that no level of regular drinking is without risks to health.
But why should high levels of alcohol trigger cancer? The biological mechanism is still unproven, although many biologists thinks alcohol damages DNA, and this in turn triggers cancer. As to whether alcohol alone does this is unlikely. Factors such as diet (such as consumption of red meat), exercise, other ill-health effects, and other genetic mutations may bias the risk of developing cancer between two individuals who drinking similar quantities of alcohol.
In addition, the review does not state how the author identified and assessed the research, including which studies were included in the meta-review and which were excluded. It is also worth noting that it is unusual for a meta-study to be written by one person, and here it is difficult to disentangle how some of the data has been interpreted. Nevertheless, the link between alcohol and several types of cancer has been established in parallel research.
While the biological mechanism remains uncertain, Professor Connor does not think this should detract from her research, telling the Daily Telegraph: “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.”
Professor Connor’s research is published in the journal Addiction. The research paper is titled “Alcohol consumption as a cause of cancer.”
This article is part of Digital Journal’s regular Essential Science columns. Each week we explore a topical and important scientific issue. Last week we considered how bacteria are being used to create a new generation of nanoelectric materials, which could aid next generation electronic devices. The previous week we weighed up the potential health benefits of drinking coffee.
