The notoriously-healthy Mediterranean diet – with a heaping helping of olive oil – has been associated with a decreased risk of breast cancer in a new study.
The Mediterranean diet consists of regularly consuming fish, nuts, legumes, fruits, vegetables, and plenty of olive oil. The eating pattern has been considered one of the healthiest for years. In 2013, a study published in the New England Journal of Medicine showed that the Mediterranean diet could protect against heart disease. A study published in JAMA Internal Medicine this past May showed it could stave off memory loss. And there are many more.
The new study looked at 4,282 women between the ages of 60 and 80. On average, participants were 68 years of age, and obese, with an average body mass index (BMI) of 30.4. A BMI of 30 is considered clinically obese.
“After a median follow-up of 4.8 years, we identified 35 confirmed incident cases of breast cancer,” study author Miguel Martínez-González, of the University of Navarra in Spain, and colleagues wrote.
The researchers discovered that women who followed a Mediterranean diet and who supplemented with 4 additional tablespoons of extra-virgin olive oil were 62% less likely to develop malignant breast cancer than those who consumed the study’s control diet. 
The findings of the study give great hope that eating a Mediterranean diet could truly be a solid preventative measure against breast cancer, as the participants were randomly assigned to different diets. The investigators say their findings also show the possibility that individuals who opt to eat healthy may also make other healthy choices that contribute to the lower risk.
The Mediterranean diet has been shown in the past to extend longevity, cut the risk of heart disease, and reduce the chances of heart attack and stroke by 30%. It may also contribute to better brain health and cut diabetes risk. 
One of JAMA’s editors, Mitchell Katz, wrote that it’s hard to know for sure which compound, or compounds, in the Mediterranean diet could be the most beneficial. But “it makes you wonder whether it’s something in the extra-virgin olive oil,” Katz said, considering the group of participants with the lowest rate of breast cancer consumed approximately 4 tablespoons of olive oil per day.
But the scientists say that their conclusions are based on 35 cases of breast cancer – a small enough number that the study is vulnerable to other factors, such as how often the women had mammograms. Clearly, women who don’t undergo mammogram are less likely to be diagnosed with breast cancer…at least not until it’s too late. And of course there is the conversation where mammograms more likely contribute to breast cancer. 
Still, the team says, any pre-existing differences between participants should have averaged out, considering the thoroughness of the process they used for randomly assigning the women. Plus, the Mediterranean diet has been proven to be beneficial to health in a multitude of other ways, which is encouraging overall.
 NBC News
Julie Fidler is a freelance writer, legal blogger, and the author of Adventures in Holy Matrimony: For Better or the Absolute Worst. She lives in Pennsylvania with her husband and two ridiculously spoiled cats. She occasionally pontificates on her blog.