Here's what the World's Healthiest Foods says about eggplant:   

   "Eggplants belong to the nightshade family of vegetables, which also includes tomatoes, bell peppers and potatoes. They grow in a manner much like tomatoes, hanging from the vines of a plant that grows several feet in height. While the different varieties do range slightly in taste and texture, one can generally describe the eggplant as having a pleasantly bitter taste and spongy texture.

   Researchers at the US Agricultural Service have found that eggplants are rich sources of phenolic compounds that function as antioxidants. Plants form such compounds to protect themselves against oxidative stress from exposure to the elements, as well as from infection by bacteria and fungi. The good news concerning eggplant is that the predominant phenolic compound is chlorogenic acid, which is one of the most potent free radical scavengers found in plant tissues. Benefits attributed to chlorogenic acid include antimutagenic (anti-cancer), antimicrobial, anti-LDL (bad cholesterol) and antiviral activities."

   Here's a link to a list of recipes for using eggplant in everything from sandwiches to lasagne.