A member of the “Solanaceae” family, the humble potato, solanum tuberosum, is a dietary staple of many nations. Other foods included in this family are eggplants, peppers, and tomatoes. The tuberous potato was a food staple in Ireland as early as the Eighteenth Century. For this reason, the it is sometimes called the Irish Potato to distinguish it from the Sweet Potato.
Solanine was first isolated in 1820 from the European Black Nightshade, solanum nigrum. It is one of the poisonous glycoalkaloids found in Solanaceae. Solanine is found in elevated levels in potatoes that have been exposed to sunlight and turned green, whether during growth, or after harvesting. The green color is not due to solanine content, but to chlorophyll. Nevertheless, the presence of chlorophyll is indicative of solanine. Curiously, damaged potatoes may also be high in solanine, and should not be consumed.
Symptoms of Solanine Poisoning
Solanine inhibits the action of neurotransmitters.¹ Symptoms of solanine poisoning may actually be delayed until six or more hours after consuming. What are those symptoms? They may include nausea, abdominal pain, vomiting, and diarrhea. Also fever, confusion, and drowsiness.² In still more serious cases of solanine poisoning, cardiac arrhythmia and respiratory failure can lead to death.
Who Is at Risk?
Although everyone is at risk if they consume an unhealthy amount of green potatoes or other source-foods containing high levels of solanine, and pregnant mothers need to be careful for the sake of their developing babies.
Other Foods Containing Solanine
Green tomatoes are relatively high in solanine, and it has been recommended that no more than 150 grams a day of cooked green tomatoes be consumed by a healthy adult. As noted, eggplant and peppers are also members of Solanaceae, however there are a few other foods containing modest amounts of solanine, including okra, blueberries, huckleberries, and artichokes.
Purdue University; Department of Horticulture and Landscape Architecture; “Potatoes – Notes”
Texas A&M University; Texas AgriLife Extension Service; “World’s No. 1 Vegetable”
The New Zealand Medical Journal; “Contaminant berries in frozen vegetables”
FDA Poisonous Plant Database; “Solanine poisoning from potatoes”
Inchem.org; “Solanine and chaconine”
CSIRO; “Greening of potatoes”
¹ Solanine inhibits butyrylcholinesterase and acetylcholinesterase.
² Conner H, Fountain J. Plants that poison: A New Zealand guide. Lincoln, New Zealand: Manaaki Whenua Press; 2009.