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Study: Alcohol, But Not Smoking, Increases Breast Cancer Risk (dateline February 5, 2003)


Alcohol increases the risk of breast cancer, but smoking does not affect a woman’s chances of developing the disease, according to a recent analysis. Researchers used data from 53 studies of 150,000 women from around the world to reach their conclusions. This report confirms previous findings that alcohol consumption seems to be a preventable risk factor for breast cancer. While smoking was not found to increase breast cancer risk, tobacco has been linked to several other serious diseases, including lung cancer and heart disease.

To conduct their analysis, Valerie Beral of the Radcliffe Infirmary in Oxford, England and her colleagues collected and studied 80% of relevant worldwide information on alcohol, tobacco use, and breast cancer. They determined the average daily alcohol consumption and smoking habits of the women, taking into account several other characteristics such age, whether the women had children, age at first childbirth, etc.

The results of the analysis showed that consuming approximately eight grams of alcohol daily (equivalent to one drink) increases a woman’s overall risk of breast cancer by 6%. The risk further increases when a larger amount of alcohol is consumed. For example, consuming 10 grams of alcohol per day increases breast cancer risk by 7.1, according to the researchers. Smoking, on the other hand, was not found to affect the risk of developing breast cancer in this study. Some previous studies have found a link between tobacco use and breast cancer risk.

Based on these data, Beral and her colleagues believe that 4% of breast cancer cases in developing countries are due to alcohol consumption. In developing countries, the consumption of alcohol is much lower and is not likely to have a significant affect on breast cancer incidence. Though smoking was not found to increase the risk of breast cancer, established data have found smoking to be a cause of the development and death from several other diseases.

This latest study confirms several previously studied reports that daily alcohol consumption increases breast cancer risk. Other studies include a 1999 article in The Journal of the American Medical Association, where researchers analyzed data from 322,647 women (including 4,335 women who had breast cancer) in Canada, The Netherlands, Sweden, and the United States. Women who consumed two to five alcoholic beverages each day. These women were found to have a 41% increased risk of developing invasive breast cancer compared to women who did not drink.

In another study published in a May 2001 issue of the Journal of the National Cancer Institute, researchers also found that moderate alcohol intake increases the risk of breast cancer. In that study, researchers followed over 50 women for eight-week periods and found that the women who consumed alcohol during that time had higher levels of hormones that have been linked to breast cancer.

Nevertheless, alcohol is only one small risk factor for breast cancer. Other risk factors include:

Approximately 80% of women who develop breast cancer have no known risk factors for the disease.

Additional Resources and References

  • The report, "Alcohol, Tobacco and Breast Cancer - Collaborative Reanalysis of Individual Data from 53 Epidemiological Studies, including 58,515 Women with Breast Cancer and 95,067 Women without the Disease," is published in the November 18, 2002 issue of the British Journal of Cancer, http://www.bjcancer.com/
  • To learn more about risk factors for breast cancer, please visit http://www.imaginis.com/breasthealth/bc_risks.asp