Potatoes might be one of the most versatile, inexpensive, filling, and nutritious foods on earth. But while you might not think twice about just cutting up a potato and cooking it, there’s actually one important thing you should be paying attention to first: the color. Specifically, the color green.
The presence of chlorophyll in a potato means that a glycoalkaloid poison named solanine is also present. A defense against insects, this nerve toxin (which is in the nightshade family) can result in headaches, vomiting, diarrhea, and even paralysis if ingested in very high amounts. So never eat any potato leaves, stems, or sprouts, and it’s probably wise to avoid eating any potatoes that have a greenish tint.[related]
But we’re not trying to fearmonger here. If you eat that odd green potato chip or end up mashing up a slightly greenish potato into your Thanksgiving side dish, nobody’s going to get sick. According to Snopes, a healthy adult would need to eat more than 4 pounds of green potatoes in one sitting in order to have any neurological side effects. Children, however, due to their smaller size, are more susceptible.
So be on the lookout for any green in your potato, which can come from excessive light, cold, or heat. You’re not going to die if you eat it, but you will be ingesting trace amounts of a nerve toxin.