By Lisa Rapaport (Reuters Health) - People with diabetes may have better brain function if they follow a Mediterranean diet rich in fruits, vegetables, legumes, whole grains, fish and healthy fats, a U.S. study suggests. Mediterranean diets have long been linked to better heart and brain health as well as a lower risk of developing diabetes. But research to date hasn't offered a clear picture of whether any cognitive benefits of eating this way might differ for people with and without diabetes, said lead study author Josiemer Mattei of the Harvard T.H. Chan School of Public Health in Boston...