Drinking wine is associated with a lower risk of developing lung cancer, according to a meta-analysis published in the November issue of Cancer Epidemiological Markers & Prevention. Those who consume more than one serving of beer or spirits in any amount, however, were found to have an elevated risk.
According to the American Cancer Society, lung cancer is the leading cause of the world's cancer-related deaths. While smoking has been identified as the greatest risk factor, a significant number of lung-cancer cases are unrelated to tobacco use. "A possible link between alcohol consumption and risk of lung cancer has long been speculated," wrote Chun Chao, research associate at the department of research and evaluation at Kaiser Permanente, Southern California, and author of the analysis.
Chao compiled data from 10 studies in the United States and Canada, as well as the Czech Republic, Spain and Uruguay, which tracked alcohol consumption and excluded tobacco smokers from the participant base. In the pool of 453,751 nonsmoking participants, 4,119 lung cancer cases arose during observation, which for some of the studies ranged up to 10 years.
Chao organized the data according to the type of beverage preferred and how much alcohol was typically consumed per day. She created two categories for the amount of alcohol consumed: up to 13 grams of alcohol per day, or more than 13 grams of alcohol per day. Chao determined that around 13 grams (18ml) of alcohol correlates to one drink: 150ml of wine, 330ml of beer or 40ml of liquor.
When Chao compared instances of lung cancer against the frequency and type of beverage consumed, the results showed that wine drinkers had a lower risk of lung cancer compared to nondrinkers, regardless of their level of consumption. They also showed a lower risk than those who drank other types of alcohol. Drinking less than one glass of wine per day correlated to a 23 percent lower risk of developing lung cancer, and drinking one or more glasses per day was equal to a 22 percent lower risk when compared to nondrinkers.
Those who drank less than one beer per day were the only other category that showed a lower risk of developing lung cancer, with 22 percent lower chance compared to nondrinkers. Drinking one beer or more per day, however, was associated with a 25 percent greater risk of lung cancer, while drinking spirits in any amount was associated with a 40 percent greater risk. The results were only statistically significant in men, however, not women.
Chao cautioned that her findings do not necessarily show a direct cause-and-effect relationship between alcohol consumption and lung cancer. However, she speculated that drinking wine did not correlate to an added risk of lung cancer for two main reasons. The first is that wine does not contain certain carcinogens, such as nitrosamines, cancer-linked compounds sometimes found in brewed beverages and products preserved with nitrites. Second, antioxidant chemicals, which are believed to have anti-cancer properties, are found in greater abundance in wine and may offset any added risk that comes with ingesting the alcohol itself.
Chao said, however, that the results cannot be translated to the general population because the study is not clinical. "The associations I reported cannot be interpreted as causal at this moment, [and] we need more evidence for causal inference," Chao said. "We also need more studies to understand the effect of heavy drinking on lung cancer risk."