Over time, eating a Mediterranean-style diet that emphasizes fish, vegetables and particularly olive oil, may lower women's risk of breast cancer compared to following a low-fat diet, suggests a new study from Spain.
In the five-year trial that randomly assigned women to different kinds of diets, those instructed to eat a Mediterranean-style diet with four tablespoons of extra virgin olive oil per day had about half as many breast cancer diagnoses as those on a low-fat diet.
"With an overall healthy diet plus extra virgin olive oil there is a reduction in the hard endpoint of breast cancer," said senior author Dr. Miguel A. Martinez-Gonzalez of the University of Navarra in Pamplona and CIBEROBN in Madrid.
"We have now evidence to support that olive oil is causally related to reduction in risk of breast cancer," he said.
The fact that the findings are based on a randomized trial, the gold-standard of research, "immediately impressed" the journal editors, writes Dr. Mitchell H. Katz, deputy editor of JAMA Internal Medicine, in an editor's note accompanying the study.