May 11, 2011 | 2 minute read

Stories on coffee and cancer have been around a long time. First, starting in the early 1980s, researchers began investigating if coffee increased our risk of pancreatic cancer. Now, after a lot of research, evidence suggests that coffee does not increase risk for the majority of cancers with some studies suggesting it offers protection.

The latest study on coffee and cancer points toward the protection side. The Swedish study suggests that drinking plenty of coffee every day may lower the risk of ER-negative breast cancer, a form of breast cancer difficult to treat.

The study was published online in the current issue of Breast Cancer Research.

In the study, researchers looked at the coffee habits of approximately 6,000 people. About half the participants had postmenopausal breast cancer. Among breast cancer overall, coffee consumption did not appear to affect cancer risk. But when separated by tumor type, participants who reported they drank five or more cups of coffee daily had a 57 percent lower risk of ER-negative breast cancer compared to those who drank one cup or less of daily coffee.

But as the authors point out, far more research is needed before scientists can make any firm conclusion on coffee and breast cancer risk. And in this study there were several limitations. For example, study researchers could only find out what hormonal form of tumor people had for about two-thirds of the participants.

In looking at all the evidence, AICR’s 2007 report judged coffee unlikely to have any effect on the risk of pancreatic or kidney cancer – the two cancers for which there was enough evidence to make a conclusion.

But with over half the adults in the United States drinking coffee daily, more coffee-cancer research is sure to come.

For other cancer-coffee research, here’s a story on how one AICR-supported neuroscientist is investigating if caffeine may fight metastasis to the brain.