Even moderate amounts of alcohol increase cancer risk, study finds
It has long been known that heavy alcohol consumption can increase the risk of various cancers, but a sobering new study has revealed that even moderate drinkers are at risk.
Experts at New Zealand’s University of Otago have warned that indulging in less than two alcoholic beverages a day puts drinkers at heightened risk of breast and bowel cancer – two of the most potentially deadly forms of the disease, as well as cancer of the mouth, pharynx, oesophagus, larynx and liver.
The study’s lead author, Professor Jennie Connor at Otago Medical School, said the findings relating to breast cancer were particularly noteworthy.
“About 60 percent of all alcohol-attributable cancer deaths in New Zealand women are from breast cancer,” she said.
“Although risk of cancer is much higher in heavy drinkers, there are fewer of them, and many alcohol-related breast cancers occur in women who are drinking at levels that are currently considered acceptable,” she added.
The study, a collaboration with the Global Burden of Disease Alcohol Group, and published in the journal Drug and Alcohol Review, builds on previous research that identified 30 percent of all alcohol-attributable deaths in New Zealand to be linked to cancer, more than all other chronic diseases combined.
It drew on evidence that alcohol causes some types of cancer after reviewing dozens of large studies conducted internationally over several decades.
Professor Connor noted that there was little difference between men and women in the number of cancer deaths due to alcohol, even though men drink much more heavily than women, “because breast cancer deaths balanced higher numbers of deaths in men from other cancer types.”
She added that while these alcohol-attributable cancer deaths only accounted for 4.2 percent of all cancer deaths in people under the age of 80, what made them so significant was that “we know how to avoid them.
“Individual decisions to reduce alcohol consumption will reduce risk in those people,” she said. “But reduction in alcohol consumption across the population will bring down the incidence of these cancers much more substantially, and provide many other health benefits as well.
“Our findings strongly support the use of population-level strategies to reduce consumption because, apart from the heaviest drinkers, people likely to develop cancer from their exposure to alcohol cannot be identified, and there is no level of drinking under which an increased risk of cancer can be avoided.
“We hope that better understanding of the relationship of alcohol with cancer will help drinkers accept that the current unrestrained patterns of drinking need to change.”
The New Zealand study echoes American research that analysed data from two large studies that monitored the health of over 88,000 women and almost 48,000 men over a 30-year period.
Their findings, published in the British Medical Journal (BMJ) last year, suggested that even light drinking – up to one drink a day for women and two drinks a day for men – could increase the risk of cancer.
In an accompanying editorial, Dr Jurgen Rehm at the Centre for Addiction and Mental Health in Toronto, Canada, said people with a family history of cancer “should consider reducing their intake to below recommended limits or even abstaining altogether, given the now well-established link between moderate drinking and alcohol-related cancers.”
According to a BBC report, Professor Sir Ian Gilmore, chairman of the Alcohol Health Alliance UK, went so far as to call for mandatory health warnings on alcohol labels to help consumers make an informed choice.
“We all have a right to know what we are putting into our bodies and, at the minute, consumers are being denied this right,” he said.
Professor Frank Murray, a liver specialist at Dublin’s Beaumont Hospital, went further, warning that there is “no safe level of alcohol consumption.”
“Alcohol consumption is associated with seven types of cancers including breast cancer in women as well as of the liver, oesophagus, and the colon,” he told Irishhealth.com.
“Consuming alcohol in a low-risk way, such as drinking one unit a day, increases the risk of getting cancer, a disease that is increasingly prevalent in our society and which is incurable in many cases,” he said.