Alcohol and Breast Cancer
Anyone who has been reading this blog regularly knows that this is a recurring topic. It keeps coming up because new articles continue to appear and because this is of real interest to me and, I assume, to many of you. It is always difficult to write about alcohol without sounding either like Carrie Nation (and do click on that link for a very sobering picture of Ms. Nation with her Bible and her hatchet) or a lush. Here is the truth, however, about me: I enjoy a glass of wine or a cocktail virtually every evening. I am quite certain, as I often tell women in my office, that my medical oncologist husband is not trying to kill me, and I have just decided that the enjoyment is worth the possible risk of increased recurrence chances. There are surely known benefits to general health of mild to moderate alcohol intake, and the lifestyle component is impossible to measure. For me, a good dinner is greatly improved with an accompanying glass of red. I am clear in my own mind that, if the cancer ever comes back, I am not going to berate myself about this and will not believe that the cabernet brought on the cancer. I suppose that I also believe, in some not-so-well-founded way, that my insistence on a healthy diet and daily exercise may counteract any negative alcohol effects. Please do not read this as a recommendation! Your habits are your choice.
But, if you share my sentiments, this is a piece of good news:
The complex association between moderate alcohol consumption and breast cancer
An excellent review article from two scientists at the National Institute on Alcohol Abuse and Alcoholism in the USA, to be published in Alcohol Clin Exp Res 2012, describes the epidemiologic and basic scientific evidence linking alcohol consumption to the risk of breast cancer.
The authors point out deficiencies in the epidemiologic data, especially that the pattern of drinking (regular moderate versus binge drinking) has generally not been taken into consideration, important given that binge drinking is associated with much higher blood alcohol concentrations and acetaldehyde accumulation. Further, epidemiologic studies usually provide data for only a short period of time, while the development of cancer may relate to exposures over many decades. The authors also comment upon the effect that underreporting of alcohol by study participants could exaggerate effects on cancer risk from light drinking. They discuss two hypotheses that could relate alcohol to breast cancer risk: alcohol as a breast tumour promoter, and alcohol as a weak cumulative breast carcinogen, and present evidence from epidemiology and basic science that would relate to each hypothesis.
Overall, Forum reviewers were enthusiastic about this review paper, considering that it clearly outlined some of the difficulties scientists have in determining the causes of cancer. They agreed with the authors' statements regarding the necessity to consider the overall net effects of moderate drinking, including reductions in the risk of cardiovascular disease and total mortality. They also agreed that future epidemiologic studies should focus on the pattern of drinking, i.e. little and often versus episodic and not just the average weekly amount of alcohol, and with their suggestions for future animal studies. One Forum reviewer cautioned that our understanding of the causes of breast cancer is still very incomplete, limiting our ability to provide wellfounded recommendations to the public regarding moderate drinking as it relates to breast cancer risk.
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