When I make a salad, I drizzle olive oil onto it and toss in a handful of toasted walnuts. Could this simple, tasty habit help me stay mentally sharp in the coming years? Maybe so. A new study in this week’s JAMA Internal Medicine suggests that eating a Mediterranean-style diet enhanced with extra-virgin olive oil or nuts is good for your mind as well as your heart. These findings, which come from a long-term clinical trial of different diets, are the first ever to show possible brain-related benefits of one eating pattern over another. The participants were part of a large Spanish trial known as PREDIMED, short for Prevención con Dieta Mediterránea (which means “prevention with Mediterranean diet”). The plant-