Nightshade plants are a family of plants that includes both edible and inedible species. The Solanaceae family, also known as the nightshades, includes plants such as tomatoes, eggplants, potatoes, peppers, and tobacco. Some species of nightshade are poisonous, such as the bittersweet and woody nightshade, which contain the toxic compound solanine. However, many nightshade plants are safe and nutritious to eat, and they contain antioxidants, vitamins, and minerals that are beneficial to health. Some preliminary research suggests that nightshade vegetables may not be the best for people with certain inflammatory and autoimmune conditions like arthritis or inflammatory bowel disease, but there is no hard evidence that they are bad for your health. Overall, for most people, there is little reason to avoid nightshade plants, and they can be a healthy addition to a balanced diet.