Now, I’ve eaten my fair share of potatoes, but I had never heard of this warning until I started watching anime. Most recently, I heard the “potatoes are poisonous” spiel while watching episode 3 of Maoyuu Maou Yuusha. In this episode, Maou requests for help from the church to spread education about agriculture – in particular potato farming.
Since potatoes are unknown in the world of Maoyuu Maou Yuusha, Maou explains that potatoes are a wonderful crop that can grow very quickly, are protected from birds since they grow underground, and are nutritious as well as cheap to produce. Of course, she adds, this miracle plant is not without its drawbacks: specifically, potatoes are poisonous (if stored incorrectly)!
And, at that pronouncement, Onna Kishi promptly chokes on a mouthful of delicious potatoes….
So is this anime food maxim fact or fiction? Are potatoes really poisonous?
Surprisingly enough, it’s a FACT!
Potatoes do indeed contain a compound known solanine, which is a glycoalkaloid that is also found in other plants such as the deadly nightshade and henbane. This toxin affects the nervous system, and may cause weakness, confusion, headaches, diarrhea, and cramps. In severe cases, coma and death may occur.
In potatoes, solanine is a defence mechanism against predators, and is mainly concentrated in the leaves, stems, sprouts and fruit of the plant. This toxin is naturally present in potatoes, but at very low levels. However, increased concentration can develop in potatoes if subjected to light, or very warm or cold temperatures. Physical damage and age can also increase the amount of solanine.
Sunlight can cause chlorophyll production, which causes the visible greening beneath the potato skin. This green hue can be used as an indicator for the presence of higher amounts of solanine. Greening and solanine accumulation can occur independently of each other, so this is not always a true indication of its toxicity.
However, not to worry, because unless you’re deliberately going out of your way to find and eat green potatoes or potato leaves, sprouts, or fruit, you shouldn’t be at risk for dying by potato any time soon. Indeed, no reported cases of potato-source solanine poisoning have occurred in the U.S. in the last 50 years. In addition, commercial potatoes are bred to be low in solanine, so an adult would have to eat 4.5 pounds of un-green potatoes all at once before feeling any symptoms (amount varies depending on a person’s weight).
That said, still take care to properly store your spuds, cut out any sprouts before cooking, and discard any green potatoes. (But, no need to be super paranoid!)
For more information about potato toxicity: