The Mediterranean diet is loaded with fruits, veggies, whole grains, healthy fats, beans, and fish. These foods have natural chemicals that help keep your inflammation in check. A Mediterranean diet also relies on olive oil, another healthy fat, to take the place of full-fat dairy products like butter. That's good if you have rheumatoid arthritis, because olive oil can also lower levels of the chemicals that cause inflammation. The fruits and vegetables in the diet are full of antioxidants that also help curb inflammation.