Alcohol Consumption and Breast Cancer Risk

Breast Cancer Exam
Breast cancer self exam.

Alcohol consumption can contribute to many different adverse health effects, but probably the most researched and documented is alcohol's effect on the risk of developing breast cancer.

There are dozens of research studies that have shown again and again that women who drink alcohol have a greater chance of developing breast cancer than those who do not drink, and neither the type of alcohol consumed nor even the frequency of drinking changes the risks involved.

Alcohol Is a Carcinogen

Since May 2000, alcohol has been listed as a known human carcinogen by the U.S. Department of Health and Human Services in its "9th Report on Carcinogens - Review of Substances for Listing/Delisting" and has been found to contribute to an increased risk of many different types of cancers.

But for women, breast cancer is the most common cancer with an estimated one in every nine females at risk to develop the disease at some point in their lifetime.

Daily Drinkers at Risk

Women at the greatest risk for breast cancer are those who have a family history of the disease. And for those women, drinking alcohol significantly increases that risk.

A Mayo Clinic study of 9,032 women found that women who had close relatives with breast cancer and were daily drinkers had double the risk of breast cancer compared to those who never drank. There is other research that indicates that drinking alcohol increases the risk of breast cancer even for those who do not have a family history.

Moderate Drinkers at Risk

Daily drinkers, however, are not the only group at risk. A Harvard Medical School study of 105,986 women found that even moderate drinkers had an increased risk of developing breast cancer.

Women who drank only 3 to 6 drinks a week had a 15% increased risk, according to the study, while women who drank an average of two drinks per day increased their risk by 51%.

The same study found that it did not matter if the women began drinking at an early age or waited until after age 40 — if they consumed alcohol, their risk increased.

The More Alcohol, the Greater Risk

There are some studies that have found that alcohol's effect on the risk of breast cancer is dose-dependent, meaning the more alcohol consumed, the greater the risk. Another study found that binge drinking — more than four drinks during one drinking session for women — increased the risk of breast cancer whether those sessions were frequent or not.​

A study conducted at the Radcliffe Infirmary in Oxford, England of 150,000 women involved in 53 previous studies worldwide concluded that drinking as little as one drink per day increases the risk of breast cancer.

The British study also found that alcohol affects breast cancer risk even when smoking tobacco is factored out. In fact, the study found that smoking increased the risk of lung cancer, but did not significantly increase the risk of developing breast cancer.

Type of Alcohol Not a Factor

Other studies have found that the type of alcohol consumed had no effect on the increased risk. Research has shown that beer drinkers, wine drinkers and whiskey drinkers all have the same increased chance of developing the disease.

Scientists are not sure exactly how alcohol consumption causes an increased risk for breast cancer, but some researchers suspect that it is because alcohol alters levels of the female hormone estrogen.

One study found that post-menopausal women who drink an average of one and a half drinks per day had a 30% greater risk of breast cancer, compared with those who did not drink at all. The study also found that women who had hormone replacement therapy for five years and drank one and a half drinks per day had double the risk.

Increased Risk for Breast Cancer Recurrence

For women who have already been diagnosed with breast cancer and who are cancer survivors, drinking alcohol is also a threat. A Life After Cancer Epidemiology study of 1,897 women found that drinking a few as three to four drinks a week can increase the risk of breast cancer recurrence.

A family history of breast cancer is not the only factor that plays a role in a woman's risk of developing breast cancer. Other risks include early puberty, late menopause, delaying childbirth until late in life, or not having children at all.

If you have any of those risk factors, and/or if you are postmenopausal, and/or if you do have a family history of breast cancer, you can significantly reduce your risk by reducing your alcohol consumption or not drinking at all.

If you try to quit drinking and find that you have difficulty in doing so, there is a world of help and support available to help you quit.


Bowlin, SJ, et al. "Breast cancer risk and alcohol consumption: results from a large case-control study." International Journal of Epidemiology October 1997.

Chen, WY, et al. "Moderate Alcohol Consumption During Adult Life, Drinking Patterns, and Breast Cancer Risk." The Journal of the American Medical Association 2 November 2011.

ECCO-the European CanCer Conference. "Wine, Women and... Spirits, Beer, and Breast Cancer Risk" 27 September 2007.

Kwan, M, et. al. "Alcohol Consumption and Breast Cancer Recurrence and Survival among Women with Early-Stage Breast Cancer," Thirty-Second Annual CTRC-AACR San Antonio Breast Cancer Symposium - Dec 10-13, 2009; San Antonio, TX.

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