Coffee provides protections from a type of breast cancer: Study

By Dr. Ananya Mandal, MDMay 12 2011

Recent research from Sweden has shown that drinking coffee may help curb the risk of developing a certain type of breast cancer.

For the study they compared coffee consumption in postmenopausal women with breast cancer and women of the same age without cancer, they found those who drank five or more cups of java a day showed a 0.43 times lower risk of estrogen-receptor negative cancers. Around one in four women diagnosed with breast cancer will have estrogen-receptor negative breast cancer, which is often resilient to drug treatment and requires intensive chemotherapy.

For the study, experts from the Karolinska Institute in Stockholm analyzed data from almost 6,000 women who were past the menopause. Those women who drank five or more cups a day had a 57 per cent reduced risk of breast cancer compared with those who drank less than one cup a day.

Writing in the journal Breast Cancer Research, the scientists concluded, “A high daily intake of coffee was found to be associated with a statistically significant decrease in estrogen-receptor negative breast cancer among post-menopausal women.” The authors also found a small reduced risk for all types of breast cancer, although this link was not significant when factors such as age and weight were taken into account.

Previous studies have suggested coffee cuts the risk of other cancers, including those targeting the prostate and liver. However, experts are divided on the benefits of coffee and some studies have shown it could even promote cancer. Research has suggested coffee may in fact cause cells to proliferate or prevent them from being repaired.

The Karolinska Institute experts believed that coffee could contain compounds that affect different types of breast cancer in different ways. It is possible that the drink fuels estrogen-receptor positive breast cancers but reduces the risk of estrogen-receptor negative breast cancer, they said. This would match the finding that drinking coffee could reduce the risk of breast cancer overall, although the experts said further studies were needed.

Research Professor Per Hall said, “We were surprised. But the result was clear. When we looked more closely the more aggressive form of cancer - the estrogen-receptor negative - was reduced by over half, meaning half as many women who drank lots of coffee were diagnosed with this cancer.” “We just don't know what might be behind this association. There are so many different compounds in coffee that it could be any one of them that could be having an effect,” he said.

Authors added that a problem was that the study rests on the women reliably recalling how much coffee they drink, and there is no record of what type of coffee they consumed - espressos, cappuccinos or decaf. Until more work is done, Professor Hall says he would not advise women to up their coffee consumption, especially since too much coffee can have side effects.

Yinka Ebo of Cancer Research UK, added, “This study does not provide firm evidence that drinking lots of coffee can help reduce the risk of breast cancer as it relied on people with cancer remembering how much coffee they drank years ago. Previous research on coffee consumption and breast cancer risk has produced mixed results, and the authors of this new study acknowledge that further work will be needed to confirm the findings.” He said there was good evidence, however, that women, who are physically active, consume little or no alcohol and keep a healthy weight after the menopause are at lower risk of breast cancer.

In a separate U.S. study it was also noted that parsley and some fruits and nuts contain a compound which could prevent breast cancer cells multiplying. Researchers from the Missouri University found that rats with breast cancer given apigenin, which is found in parsley, celery, apples, oranges and nuts, “developed fewer tumors and experienced significant delays in tumor formation” compared with rats with breast cancer that were not.