Study Finds Mediterranean Diet May Lower Breast Cancer Risk

Right this minute, plenty of researchers are searching for connections between dietary patterns and chronic illnesses. It's important to remember that these studies are just one piece of the puzzle, not a definitive tie between cause and effect. 

However, knowledge is power and valid scientific findings certainly deserve airtime—particularly when the practices they highlight are relatively easy and cost-effective to implement.

A case-controlled study conducted in Iran and published on Frontiers in Nutrition found a significant inverse association between the Mediterranean diet and breast cancer.

In this research, individuals with the highest tertile of the Mediterranean diet score compared with those in the lowest tertile were 57% less likely to have breast cancer1. This relationship was most significant among postmenopausal women.

Previous studies on the association between diet and breast cancer are mostly from Western populations where data from Middle East countries was not often included, hence why this study specifically set out to gather data on Iranian women, as the prevalence of breast cancer in Middle East countries is high2, yet the analytic data available is quite low. 

The classic Mediterranean diet focuses on eating real, whole foods and is modeled after countries lining the Mediterranean Sea. It centers fruits, vegetables, whole grains, beans, legumes, nuts, seeds, olive oil, herbs, and spices and limits processed foods, red meat, and added sugars.

For this study, researchers enrolled 350 women with new cases of breast cancer (including stages I-IV) and 700 women to represent a control group with equal socioeconomic and age status.

A nutritionist then evaluated dietary intake using a 106-item Willett-format semi-quantitative dish-based food frequency questionnaire (SQ-FFQ), which was specifically created and validated for the Iranian population to create scores based on how closely participants follow the Mediterranean diet.

They computed scores of the Mediterranean diet based on nine diet components, including servings of fish, fruits, vegetables, legumes, nuts; ratio of monounsaturated fatty acids (MUFAs) to saturated fatty acids (SFAs); and negative components, including grains, dairy, meats (including poultry and red meat) and processed meat. They then added those scores together to get the total Mediterranean diet value. 

More studies are needed to confirm these findings across different populations and dive deeper into what, exactly, makes this diet potentially cancer-protective.

A study found that individuals who closely follow a Mediterranean diet were 57% less likely to have breast cancer. Researchers suspect the diet's anti-inflammatory, estrogen-supportive, and antioxidant properties could be driving this impact.