They're a great source of vitamin C, vitamin K, vitamin B6, thiamine, niacin, magnesium, manganese, phosphorus, copper, fiber, folic acid, potassium, and more.
Sometimes people are too reliant on too much oil for cooking them. When we are getting them ready for "eggplant" Parmesan, or vegetable lasagna, we slice into rounds, oil lightly, and cook in the oven on baking sheets before using.