Guacamole has been popular since the height of the Aztec empire. In fact, the Aztecs likely made their guacamole much the way we do today: mashing avocados with salt, a bit of onion, chili pepper and tomatoes. Avocados (sometimes called alligator pears because of their textured skin) are high in monounsaturated fat (the good fat) and are a wonderful source of lutein, the antioxidant that some studies suggest may help to protect vision among other health benefits.