Mashed potatoes, baked potatoes, and French fries are not as harmless as they look.
The benign potato, often a favorite staple of family meals, is not just an innocent tuber. Potatoes are actually a member of the Nightshade family. Potatoes and their mild mannered counterparts contain chemical compounds called solanine and chaconine, both glycoalkaloids. Both occur naturally in potatoes as a defense mechanism, as they have pesticidal and anti-fungal properties.
Solanine is potentially poisonous to humans, and can cause gastrointestinal distress, diarrhea, vomiting, burning of the throat, dizziness, and even cardiac issues. In severe cases solanine has been known to cause hallucinations, paralysis, fever, and other severe symptoms.
Solanine develops in potatoes when they are exposed to light. As long as potatoes are stored in a cool, dry, dark place and not served when they appear green, they are perfectly safe to eat.