Scientists now believe that drinking a daily glass or two of wine carries no greater risk of throat cancer than not drinking at all. In fact, those who drink wine in moderation may enjoy a lower risk of some cancers. More than that, however, eliminates any reduction in risk, according to a new study published in the April issue of Gastronenterology.
Cancer of the esophagus is currently a hot research topic. It's the sixth most common form of cancer, and mortality rates are disproportionately high. Recent scientific discoveries have altered views of what is or isn't a risk factor for the disease. Traditionally, long-term consumption of alcohol was viewed as detrimental to the throat. The Mayo Clinic classifies excessive alcohol use as a risk factor, equal to smoking, a poor diet and poor dental hygiene.
But that view may be changing. "It is important to distinguish between the two major types of esophageal cancer, namely squamous cell cancer (SCC) and adenocarcinoma (AC)," said the study's lead author, Nirmala Pandeya, a researcher at the University of Queensland, where the throat cancer study is being conducted, part of the larger Australia Cancer Study. "Previous research has shown alcohol is a strong risk factor for SCC, and our data supports this conclusion," she said. "In contrast, we found no evidence that alcohol is a risk factor for AC."
This result echoes an earlier study that found drinking wine in moderation may offer protection from the onset of Barrett's Esophagus, a precursor to AC esophageal cancer. Barrett's Esophagus occurs when chronic heartburn singes throat tissue, eventually changing cells from healthy to malignant.
The Queensland scientists wanted to see if drinking, limited to the U.S. dietary guidelines of no more than two drinks a day for men and one for women, created an additional risk of throat cancer. "Recently, there has been a large increase in the incidence of esophageal cancer in countries around the world, including Australia," the authors note on their website. "As yet, there is no clear reason why."
The team pulled data on 1,577 throat cancer patients being followed in the ongoing Australian Cancer Study. They also selected an equal number of people, stratified by gender and lifestyle habits, from the Australia electoral roll. These subjects were cancer-free.
Participants were asked to provide their daily habits, including which alcoholic beverage they preferred to drink, if any. The incidence of heartburn and other potentially related factors, such as tobacco use and aspirin consumption, were also recorded.
By comparing the rate of throat cancer across beverage-specific lines, the scientists found that moderate wine and fortified wine and spirits drinkers enjoyed a "significantly lower risk of all throat cancers than nondrinkers," according to the study. In fact, the moderate consumption of these beverages was linked to a 30 percent lower risk of throat cancers. However, when the individual regularly drank more than USDA guidelines, the risk of SCC cancer was quadrupled. The risk of AC cancer remained similar to abstainers in this group. Beer drinkers showed no higher or lower risk than nondrinkers.
Notably, the authors separated red and white wine drinkers to see if the higher levels of antioxidants found in reds, including polyphenolic compounds like resveratrol, may lead to differing results. "Experiments suggest that resveratrol has anticancer activity across a spectrum of biologic pathways, and this may explain why moderate wine drinkers apparently enjoy lower risks of cancer," wrote the scientists. But they could not support such a conclusion. "Arguing against this explanation was our finding that similarly reduced risks of cancer were observed for those who drank modest levels of white wine."
Pandeya added that she would like to conduct more studies. "Further studies under a fully controlled environment are required to understand how different types of beverages have different effect on this cancer," she said.