The Mediterranean (MED) diet—rich in olive oil, fruits, vegetables, legumes, nuts and seeds—is a recommended way to reduce the risk of heart disease, type 2 diabetes and other adverse health outcomes. But exactly how and why the MED diet lowers risk for type 2 diabetes has remained unclear. In a study conducted by investigators from Brigham and Women’s Hospital, researchers examined outcomes for more than 25,000 participants in the Women’s Health Study, a longitudinal cohort study that followed female health professionals for more than 20 years. In a paper published in JAMA Network Open, the investigators report that women who adhered to a more MED-like diet had a 30 percent lower rate of type 2 diabetes than women who did not. The team examined several biomarkers to look for biological explanations for these results, finding key mechanisms including insulin resistance, body mass index, lipoprotein metabolism and inflammation.