For women, breast cancer is the most frequently diagnosed malignant tumor and is the leading cause of death among women. Since 2008, breast cancer incidence worldwide has increased by more than 20 percent and mortality from breast cancer has increased by 14 percent.
Historically breast cancer rates have been lower in Northern or Central European countries where the Mediterranean diet (MedDiet) is commonly consumed. The MedDiet is characterized by an abundance of plant foods, fish, and the consumption of extra virgin olive oil (EVOO). Numerous prospective cohort studies have evaluated the association between the MedDiet and breast cancer risk, but results have often been limited and conflicting. Until recently (Sept 2015) there has never been a randomized control trial to help establish more solid evidence.