A daily glass (or two) of red wine may reduce the risk of lung cancer in men, particularly in smokers, according to research published in the October issue of Cancer Epidemiology, Biomarkers & Prevention.
Smokers suffer from an especially high risk of lung cancer. According to the American Cancer Society, 213,380 new cases of lung cancer were reported in the United States in 2007, with 160,390 deaths, making it a leading cause of cancer death in the country.
Previous research has suggested a possible link between alcohol consumption and lung cancer, but studies have yet to provide consistent evidence. In order to further explore the relationship, researchers from Kaiser Permanente's Department of Research and Evaluation in Pasadena, California, pulled data on 84,170 men, aged 45 to 69 years old, who took part in the California Men's Health Study from 2000 to 2003, which analyzed health patterns among members of a large, prepaid medical plan in the state.
The researchers selected the 84,170 subjects from a pool of nearly 850,000 men, based on their alcohol preferences and patterns of smoking. The Men's Health Study had conducted in-depth surveys on drinking habits, socioeconomic status, body mass index and history of chronic diseases. During that period, the study identified 210 cases of lung cancer.
The Kaiser scientists compared incidents of lung cancer to exposure to smoking, such as whether or not the person smoked or instead inhaled second hand smoke, as well as to their pattern of alcohol consumption.
They found that men who drank red wine regularly, both smokers and nonsmokers, had a lower chance of lung cancer. Moreover, the difference in risk between the two groups was large. The study found that nonsmoking men who drank a glass or two of red wine a day were 4 percent less likely to get lung cancer. Yet, for smokers who drank a glass or two of red wine a day, the researchers reported a 60 percent reduced lung cancer risk.
Despite the findings, the researchers stress that the best way to reduce lung cancer risk is to stop smoking. Even the smokers who drank wine faced a greater risk of lung cancer than nonsmokers. Additionally, for drinkers of beer, liquor or white wine, the results were not as positive. Moderate white wine drinkers who smoke showed a slightly lower risk of lung cancer than nondrinking smokers, whereas beer and liquor drinkers showed an equal or slightly greater risk.
The fact that red wine drinkers showed the lowest risk of lung cancer, the study theorizes, may be due to dietary factors (red wine drinkers on average ate the highest amount of fruit and vegetables), but is more likely due to differences in the chemical makeup of red wine compared to other alcoholic beverages.
"An antioxidant component in red wine may be protective of lung cancer, particularly among smokers," said Chun Chao, Ph.D., the co-author and a research scientist at Kaiser Permanente. "Red wine is known to contain high levels of antioxidants. There is a compound called resveratrol that is very rich in red wine because it is derived from the grape skin. This compound has shown significant health benefits in preclinical studies." The study went on to report that white wine has similar chemical compounds, but in lower amounts.
Resveratrol shows promise as an anti-cancer agent and is currently being tested as an anti-cancer drug. The compound may also make cancer cells more receptive to chemotherapy treatment.
The text of the study does sound a few warnings about the results. The scientists write that they didn't consider alcohol consumption at levels higher than five drinks per day, and that drinking this amount is an overall cancer risk. Furthermore, the group of red wine drinkers contained the fewest smokers, which may diminish the findings.
"The effect of moderate red wine intake on lung cancer risk still needs to be confirmed by other studies," Chao said. "Even if the reduced risk is confirmed, it is still not clear whether it is resveratrol alone or the combination of the various polyphenols in red wine." She also said there is currently no direct evidence that taking resveratrol as a dietary supplement in pill form would work to prevent lung cancer. "My first advice to men who smoke is to stop smoking. Even men who smoke and drink one or two glasses of red wine per day still face a greater risk of lung cancer than nonsmokers."