Are Sprouted Potatoes Safe to Eat?
The Bottom Line
You're better off tossing potatoes that have turned green or grown sprouts. Eating them puts you at risk for potential toxicity from solanine and chaconine, two natural toxins found in green or sprouted potatoes.
The Full Story
Many of us have been guilty of buying a huge bag of potatoes, using a few, and leaving the rest sitting in the bag for a month before we remember they're still there. Now the month-old potatoes are green and have little sprouts growing out of them. Why are they green? Are the sprouts poisonous? Can you still eat them?
Potatoes contain two kinds of glycoalkaloids, both natural toxins, called solanine and chaconine. Exposure to light greatly increases the formation of chlorophyll and glycoalkaloids. Chlorophyll is responsible for the green color of many plants and is not toxic. However, the green of chlorophyll is a marker that can let you know that there could be an excess of glycoalkaloids.
The entire potato plant contains glycoalkaloids, but the highest concentration is found in the leaves, flowers, "eyes," green skin, and sprouts. The lowest concentration is found in the white body of the potato. Toxicity is increased by physical injury to the plant, low storage temperature, and storage in bright light. Cooking potatoes by baking, boiling, frying, and microwaving does not eliminate glycoalkaloids. However, removing the skin before cooking can reduce the glycoalkaloid content in a raw potato.
Both solanine and chaconine cause toxicity through cell disruption leading to gastrointestinal symptoms such as vomiting, abdominal pain, and diarrhea. Some people may also experience headache, flushing, confusion, and fever. There have been a few cases of death from eating toxic potatoes. The onset of symptoms is typically within a few hours but can be as delayed as long as a day.
The majority of patients with mild symptoms can remain at home. If symptoms are severe and persistent or if you are unable to hold down fluids, medical attention might be needed.
Glycoalkaloid toxicity from potatoes can be minimized by only buying potatoes as you need them, storing them in a cool and dry place, and peeling them before eating them. Do not store potatoes and onions together as gasses from onions can speed up potato sprouting. The advice for avoiding any type of foodborne illness applies to potatoes: when in doubt, throw them out.
If you suspect someone is having symptoms from eating a bad potato, get help from Poison Control online at poison.org or call 1-800-222-1222.
Diana M. Pei, PharmD
Certified Specialist in Poison Information
Poisoned?
Call 1-800-222-1222 or
Prevention Tips
- Buy potatoes shortly before you need them.
- Inspect potatoes, looking for sprouts and green peels.
- Store potatoes in a cool, dark place.
- Remove potato skins before eating.
- If in doubt, throw it out!
This Really Happened
Case 1. A husband and wife had green potatoes for breakfast. Three hours later, the wife had diarrhea and nausea while the husband remained fine. She was able to stay at home and stay hydrated. Eight hours after breakfast the wife started to feel better.
Case 2. A 42-year-old man arrived at an emergency room after eating potatoes with sprouts on them. He had nausea, vomiting, and dizziness. He was given intravenous fluids, anti-vomiting medication, and an anti-anxiety medication. He was admitted to the hospital for further monitoring and care. He was discharged after 3 days.
For More Information
References
Poisoned?
Call 1-800-222-1222 or
Prevention Tips
- Buy potatoes shortly before you need them.
- Inspect potatoes, looking for sprouts and green peels.
- Store potatoes in a cool, dark place.
- Remove potato skins before eating.
- If in doubt, throw it out!
This Really Happened
Case 1. A husband and wife had green potatoes for breakfast. Three hours later, the wife had diarrhea and nausea while the husband remained fine. She was able to stay at home and stay hydrated. Eight hours after breakfast the wife started to feel better.
Case 2. A 42-year-old man arrived at an emergency room after eating potatoes with sprouts on them. He had nausea, vomiting, and dizziness. He was given intravenous fluids, anti-vomiting medication, and an anti-anxiety medication. He was admitted to the hospital for further monitoring and care. He was discharged after 3 days.