A new study shows that eating a diet rich in staples of a Mediterranean diet — fish, olive oil, nuts, vegetables, and whole grains — may help reduce the risk of developing a type of breast cancer that cannot be treated with hormone therapy.
The study, conducted for the World Cancer Research Fund and published Monday in the International Journal of Cancer, found that the Mediterranean diet might greatly reduce the chances of women getting post-menopausal ER-negative cancer. Piet van den Brandt of Maastricht University in the Netherlands, the study's lead researcher, said this "usually has a worse prognosis than other types of breast cancer," and the research "can help to shine a light on how dietary patterns can affect our cancer risk."
The study followed 62,573 women between 55 and 69 who tracked their diets over two decades, starting in 1986. Over the course of the study, 3,354 women were found to have breast cancer, with 1,033 cases not analyzed because of family histories of breast cancer or incomplete diet data. The researchers concluded, after analyzing individual components of the subjects' diets, that nut intake was most strongly inversely associated with ER-negative breast cancer, The Guardian reports, followed by fruit and fish. They suggested that if everyone ate the highest defined Mediterranean diet — low in red meat, sugar, and white rice and bread — close to 33 percent of ER-negative breast cancer cases and 2.3 percent of all breast cancer cases could be avoided. Catherine Garcia