Eggplant is a member of the nightshade family, a group of vegetables that also includes tomatoes, potatoes and bell peppers. For some individuals, consuming vegetables from the nightshade family can cause negative side effects, and allergic reactions to eggplant have been reported. Still, eggplant ranks high in terms of both overall nutritional value and taste, and most food scientists agree that eggplant can be a healthy part of most diets.
According to India's Central Food Research Institute, eggplant can cause allergic reactions. Severe reactions can include throat swelling and nausea, although more common reactions include itchiness and rash. Eggplant allergies do not tend to be as common or as severe as allergies to other members of the nightshade family, such as tomatoes or bell peppers. Still, parents should monitor their children when serving eggplant. Common antihistamines can treat most eggplant allergies.
In 1993, the New England Journal of Medicine reported that eggplant has the highest concentration of nicotine, the addictive stimulant found in tobacco, of any commonly consumed vegetable. According to the New York Times, however, eggplant contains nicotinic acid, which has a similar molecular structure to nicotine, but is not the same thing as nicotine, and does not have nicotine's addictive or stimulating properties.The Times further states that the nicotinic acid in eggplant makes it an excellent source of niacin, an essential vitaimin for blood and brain function.
According to the University of Illinois Agriculture Extension, eggplant is a reasonably good source of folate, potassium, and fiber. Folate is essential to blood health, while potassium aids brain function, and fiber helps the digestive tract run smoothly. Eggplant served with its skin is a better source of nutrients than peeled eggplant. Eggplant skins can develop a bitter taste as the eggplant grows and ages; this is why many chefs recommend fresh, young eggplant for the best combination of nutrition and taste.