Toxicity
Potatoes are a member of the nightshade family, along with tomatoes, eggplants, peppers and tobacco. All members of this family are known for protecting themselves with toxic alkaloids, and potatoes are no exception. They produce two alkaloids, solanine and chaconine, that are dangerous to humans. Ordinarily, a potato contains only small amounts of both. However, sprouted or green potatoes can have unusually high quantities of solanine. Solanine causes diarrhea, nausea, cramping, headaches and in extreme cases organ failure and death. Green potatoes should not be eaten, either raw or cooked.