Two new studies warning that wine consumption increases a woman's risk of breast cancer are prompting a lot of concern among female wine drinkers. Multiple studies now point to alcohol consumption as a breast-cancer risk factor, but other studies have found that wine, particularly red wine, may have cancer-fighting properties. The controversy has spurred more research.
A recent Oxford University study found that even light to moderate amounts of alcohol can increase the risk of certain cancers, particularly breast cancer, but that moderate wine consumption could decrease the risk of other cancers. For those hoping that red wine has cancer-fighting properties, a new study from the Fred Hutchinson Cancer Research Center, published in the March issue of Cancer Epidemiology, Biomarkers and Prevention, didn't inspire confidence.
The researchers found that women who consumed 14 alcoholic drinks or more per week faced a 24 percent increase in breast cancer on average, regardless of the type of drink, compared with nondrinkers. The team interviewed 6,327 women with breast cancer and 7,558 women without the disease about their drinking habits and other breast-cancer risk factors, such as family history or postmenopausal hormone supplements. The study participants, ages 20 to 69, were from Wisconsin, Massachusetts and New Hampshire.
"We were interested in teasing out red wine's effects on breast-cancer risk. There is reason to suspect that red wine might have beneficial effects based on previous studies of heart disease and prostate cancer," said lead author Polly Newcomb, in a statement.
"We found no difference between red or white wine in relation to breast-cancer risk. Neither appears to have any benefits," said Newcomb. "If a woman drinks, she should do so in moderation—no more than one drink a day. And if a woman chooses red wine, she should do so because she likes the taste, not because she thinks it may reduce her risk of breast cancer." Newcomb did not respond to an interview request from Wine Spectator.
The study does have some limitations. The authors admit that they could not measure drinking habits effectively. "We did not have data on drinking patterns, i.e. moderate versus binge drinking," the text read. The study hopes to address this gap in future research. Critics of the recent studies of wine as a breast-cancer risk point to the fact that most of the studies measure glasses of wine consumed per week, failing to take into account whether women are drinking one to two glasses a night, or drinking it all in one or two nights during weekends.
Another recent study looked at women with a history of breast cancer. Scheduled to be published in the April 15 issue of the American Journal of Epidemiology, the research found that alcohol consumption, be it one drink a day or more, is associated with a 20 percent to 30 percent increase in the risk of breast-cancer recurrence.
Researchers from Mount Sinai Hospital in Toronto examined health registries in the United States and Denmark to identify women with breast cancer. The scientists looked at the rates of breast cancer among more than 2,000 women who were cancer-free and developed the disease, and those who experienced a recurrence after treatment. The researchers only looked at very general categories of alcohol consumption—nondrinkers, those who consumed less than one drink a day and those who consumed one drink or more per day—but they found that rates of breast cancer and breast-cancer recurrence were higher among both groups of drinkers than among nondrinkers.
Lead author Julia Knight, a senior investigator at the Prosserman Centre for Health Research at Mount Sinai, admits that future research will need to take a better look at alcohol-drinking patterns not measured by this study, such as binge drinking versus daily drinking. "In our study, most women did not report drinking very much, most less than one drink per day, but I think that a limitation is that we did not collect information about changes in drinking," said Knight.
"We could not really look at whether it made a difference if they had reduced the amount of alcohol they drank when they were diagnosed with breast cancer, though few women gave it up altogether," she said. "I think that this is an area that needs further study."
"The bottom line is that alcohol does increase the risk of breast cancer, but not by a huge amount. Some women may prefer to avoid it altogether, but the occasional drink, less than once a week, is unlikely to have much of an effect on breast-cancer risk," she said. "I would be concerned about women drinking more than a drink a day. For in-between amounts, it really depends on what a woman is comfortable with. I really think that as with many things, moderation is the key."