It seems strange to think, that drinking coffee can reduce the risk of breast cancer.  Believe it or not, it is true, and proven in a Swedish clinical study that was published in BioMed Central’s open access journal:  Breast Cancer Research.

The research team was made up of eight researchers in Sweden, based at the Karolinska Institute in Uppsala.  The bottom line finding was that women who drank coffee, were at a lower risk of developing estrogen-receptor (ER)-negative breast cancer.

The Swedish research team compared the lifestyles and coffee intake of women who had breast cancer and women of the same age without breast cancer.  What they found was that women who were big consumers of coffee had a significantly lower occurrence of breast cancer than the other group of women, who seldom indulged in tcohe dark, bitter brew.

As with most things in life, there was more to it than just coffee.  The research team also found a number of other things that seemed to impact breast cancer rates, for example:  weight; level of activity; age of menopause; extent of exercise; education; and family history of breast cancer.

Knowing this, researchers were able to re-analyze their data, taking into consideration these confounding factors.  After this re-assessment, they found that the defensive impact of coffee was limited only to women who were prone to the ER negative variety of breast cancer.

To put things into perspective, the team of researchers, acknowledging that there is often conflicting information regarding the beneficial effects of coffee, compared the results obtained in their research, to a similar German study.  Their comparison showed that while the studies both generated data trending in the same direction, the German results were less compelling.   The Swedish investigators suggested that this difference could be due to a variety of causes to include:  differences in patient attributes; the type of coffee bean used; and the way in which the coffee was prepared.

Further to that, the investigators suggested that the protective effect was not likely due to the phytoestrogens found in coffee.  They base this supposition on the fact that there was no reduction in the incidence of ER-positive breast cancer in their study (phytoestrogens have been previously shown to reduce the incidence of both ER negative and ER positive breast cancer).

All that to say, there is strong evidence that coffee consumption can reduce the risk of certain types of breast cancer. What is not clear is:  how much coffee is needed for protection; how it works; and the specific chemicals involved.  It is evident that not every cup of coffee is the same, and a variety of brewing methods exist.  Therefore, further research must be completed to solve this mystery.  However, the research team is confident that they will discover the answers to the remaining questions.


BioMed Central (2011, May 11). Coffee reduces breast cancer risk, study suggests.

Li J, Seibold P, Chang-Claude J, et al. Coffee consumption modifies risk of estrogen-receptor negative breast cancer. Breast Cancer Res. 2011 May 14;13(3):R49. doi: 10.1186/bcr2879.