“We think this may be connected with how the coffee is prepared and what bean has been used,” the study’s author Jingmei Li, said in a statement.
In the study the Swedish scientists compared the lifestyles of women with breast cancer to those of the same age without cancer. Data was also gathered on their regular coffee consumption.
Breast cancer can be sub-divided into hormone responsive (ER positive) and non-hormone-responsive (ER negative) subgroups.
The scientists found that the regular coffee drinkers among the group were less likely to develop the ER-negative breast cancer than those that rarely or never drank coffee.
Other factors also played in such as age at the beginning of menopause, fitness level and lifestyle, education and family history of breast cancer.
“But coffee remained even after we had excluded all the other factors that could make a difference,” professor Per Hall told the Göteborgs-Posten (GP) newspaper.
According to Jingmei Li, the research does not conclude what it is about coffee that has the beneficial effect on the health of the women in the study.
“However, it isn’t likely to be the presence of phytoestrogens in coffee, since we saw no reduction in ER-positive types of cancer, which is hormone responsive,” she said.
The link is good news for the Nordic countries as they are world leaders in coffee consumption.
According to World Resource Institute statistics from 2008, the Finns lead the group drinking the equivalent of 12 kilogrammes per capita per annum.
Sweden comes in sixth with an average of 8.2 kilogrammes consumed a year.
The study consisted of 2,800 women with breast cancer and 3,000 women who were healthy.
The results of the study are published in the medical journal Breast Cancer Research.