A study that examined the eating habits of 90,000 women over time found that there was an increased risk of breast cancer in those women who ate red meat. The risk of breast cancer was twice as high in the women who ate the most red meat compared to those who ate the least. This is a well-conducted study that comes out of the Harvard Nurses Health Study – a group of nurses who have volunteered to answer questions about their lifestyle over time that has given us insight into risk factors for various diseases.

The study also suggested something called a “dose response” association – meaning that the more red meat a woman consumed, the greater her risk of breast cancer. These findings are not unexpected – similar studies have shown an increased risk of breast cancer as well as colon and prostate cancer – in people who eat red meat compared to non-meat eaters. Red meat also increases the risk for heart disease (coronary artery disease).

Another line of evidence comes from Japan. In Japan, where red meat consumption is very low, and dietary portions are small and rich in fish, there are low rates of breast, colon and prostate cancer. When Japanese women move to the United States and adopt our diet, their rates of breast cancer approaches those of the US population. The same is true for Japanese men and prostate cancer, and both sexes and colon cancer.

The study shows an association – that the risk seemed to be doubled in those women consuming the most red meat compared to those consuming the least. An association is different from cause and effect, so I don’t think these findings are cause for alarm or excessive worry. We still don’t know what truly causes breast cancer in the overwhelming majority of women who develop it. But I would consider this study “food for thought.”




Kevin Knopf, M.D., M.P.H., Pacific Hematology/Oncology Associates, San Francisco, CA. Provided by VeriMed Healthcare Network.