Friday, July 29, 2011
Red wine may protect against breast cancer for some women at increased risk
As we have discussed here before, the question of alcohol consumption and breast cancer is a volatile one, but a new study helps to shed some light on the subject. It becomes especially difficult for a subset of women with a genetic trait that places them at increased risk. Two genes, called BRCA1 and BRCA2, are mutations of genes that normally code for tumor suppression. When one of these mutations is present, the chances of developing breast cancer are substantially increased, and it is now routine to test for them when there is a family history of breast cancer. And given the consensus that alcohol consumption further increases the odds of developing breast cancer, it might make sense that the BRCA gene and drinking would be an especially dangerous mix. But when it comes to red wine, the story takes a different turn.
This new study, from the University of Ottawa in Montreal, looked at a large population of women with breast cancer, and tested them for BRCA. Additionally, drinking habits were determined by questionnaire. Interestingly, women with BRCA1 who were primarily red wine drinkers had about half of the expected incidence, and alcohol had no correlation at all. For BRCA2 positive women, alcohol was independently associated with breast cancer but red wine had no relationship.
So for BRCA-positive women, the effect of red wine really depends on which type; BRCA2 women should probably seriously consider avoiding alcohol of any type (unless they choose to have prophylactic mastectomy with reconstruction) while BRCA1 women might seriously consider cultivating a taste for cabernet. It’s a confused message, since the original purpose of the study was to clarify the magnitude of alcohol as a risk factor for BRCA-positive women, but the unexpected benefit for wine drinkers adds a layer of complexity. It’s not the first crack in the consensus about wine and breast cancer though, since populations where wine is regularly consumed there is a much lower incidence of breast cancer. The difficulty is statistically teasing out the true wine drinkers from the mixed and erratic drinking patterns in most populations.