Dan Fields is sharing Health Secrets of the Mediterranean Diet with us. It’s not just the olive oil that makes this eating plan so good for you. Scientists have known for decades that people who eat a traditional Mediterranean diet have lower rates of heart disease, and more-recent research has shown that such a diet can help protect against everything from cancer, diabetes, and obesity to Alzheimer’s and Parkinson’s diseases. Olive oil may be the best-known Mediterranean ingredient, but the diet also emphasizes fresh fruits and vegetables, whole grains, beans, nuts, and fish.