Here's something that's easy to stomach: Drinking light to moderate amounts of wine is not associated with a greater risk of gastric cancer in women, according to a Swedish study. While light to moderate alcohol consumption was associated with a greater risk of gastric cancer, when the types of alcoholic beverages were examined separately, women who drank wine in particular showed a reduced risk—around a third lower than that of nondrinkers.
Light to moderate alcohol consumption was associated with an increase of up to 33 percent in the risk of gastric cancer, according to the research, published in the Jan. 15, 2007 issue of the International Journal of Cancer. The study noted that previous research on the association between gastric cancer and alcohol consumption yielded "inconsistent results," with some studies finding a link between alcohol and gastric cancer and others not; the authors felt that their further research was necessary because alcohol is consumed in many forms worldwide and stomach cancer is the second most common form of cancer deaths globally.
The study was led by Susanna Larsson at the Karolinska Institute in Sweden, in association with Harvard Medical School. The researchers pulled data on 66,651 women from the Swedish Mammography Cohort, which ran from 1987 to 1990. In that study, 36,664 women completely filled out questionnaires on their smoking habits, body mass and diet. That included reporting what types of alcohol they drank and how much, as well as what they ate and how frequently they consumed fruits, vegetables, processed meats and coffee. (The National Institutes of Health names salted, cured and smoked foods as potential risk factors for stomach cancer.)
Because the mammography study didn't track gastric cancer, the scientists identified cases among the study participants by reviewing the National Swedish Cancer Registry, which documents nearly 100 percent of cancer cases in Sweden. By cross-referencing the subjects' drinking habits with their rates of gastric cancer, the researchers were able to compute a risk factor.
Of all the groups, wine drinkers had the second lowest rates of gastric cancer. Compared with nondrinkers, the women had a 35 percent lower risk if they drank less than half a glass of wine per week and a 29 percent lower risk if they consumed more than half a glass per week. (Because the women who preferred specific alcoholic beverages drank very little, the researchers defined the consumption categories at lower levels than one typically sees in studies on alcohol and health.)
The only women who showed a lower risk of cancer than wine drinkers were those who consumed light amounts of light beer--beer with less than 2 percent alcohol. The women who drank one to two servings of light beer per week were 36 percent less likely to get stomach cancer than nondrinkers. However, the women who drank more than two beers per week had a risk similar to that of nondrinkers.
Hard-liquor drinkers showed an increased gastric cancer risk of 19 percent when they drank under half a serving per week and 49 percent increase with more than half a serving per week. But the scientists downplayed these results, saying they were insignificant because the number of women who drank spirits exclusively was small, but also because that risk was low when compared to that of women who drank strong beer (defined as more than 4.5 percent alcohol).
The women who drank a serving of strong beer more than once a week showed a 250 percent increase in the risk of stomach cancer, while even women who had only a half-serving per week had a risk 124 percent greater than nondrinkers.
The scientists said the likely explanation for these results is the presence of a known carcinogen found in some types of alcoholic beverages. Beer, for one, contains the nitrate NDMA, "which is a potent carcinogen in animals," according to the authors. Several studies have linked NDMA to cancer, and while a 1983 study found the compound's levels to be elevated in strong beers, changes in the manufacturing process since then have reduced NDMA levels significantly. Whiskey and processed meats also contain significant levels of the compound, they added. Wine, on the other hand, does not contain NDMA.
The results of the study echo Danish research that found wine drinkers to be at a lower risk of gastric cancer than beer and spirits drinkers.