Solanine Poisoning: What Poisoning Does Green Potatoes Cause?

December 16, 2025 •

4 min read

According to the National Capital Poison Center, green potatoes are not safe to eat and can cause adverse health effects due to the formation of a toxic compound. This greening is a natural process that signals the presence of elevated levels of toxic glycoalkaloids, primarily solanine, which can lead to poisoning if consumed in sufficient quantities.

Quick Summary

Green potatoes pose a health risk by producing toxic glycoalkaloids, mainly solanine, when exposed to light. Symptoms include gastrointestinal and neurological issues, though severe cases are rare. Peeling and trimming green areas can reduce the toxin, but proper storage is key to prevention.

Key Points

Solanine Toxin: Green potatoes cause solanine poisoning, a toxic reaction from glycoalkaloids produced by the plant when exposed to light.
Visible Warning: The green color is not the poison, but a signal that solanine production has been triggered; the highest concentration is near the green skin and in sprouts.
Poisoning Symptoms: Symptoms of solanine poisoning include gastrointestinal issues like nausea, vomiting, and diarrhea, and more rarely, neurological problems like headache and confusion.
Proper Trimming: For slight greening, peeling the potato and generously trimming away the green parts and any sprouts is often sufficient to make it safe.
Storage is Key: Prevent greening and solanine build-up by storing potatoes in a cool, dark, and dry place, away from light exposure.
Discard if Bitter: If a potato, even after trimming, has a bitter taste or is extensively green, it contains high levels of solanine and should be thrown out.
Higher Risk for Children: Infants and young children are more vulnerable to solanine poisoning due to their lower body weight, so exercise extra caution with their food.
Cooking is Not Enough: Boiling, baking, or frying does not effectively destroy solanine, so proper preparation and trimming are essential for safety.

Understanding Solanine and Its Connection to Green Potatoes

When a potato is exposed to light during storage, it naturally begins to produce chlorophyll, the harmless green pigment essential for photosynthesis. However, this light exposure simultaneously triggers the production of solanine, a colorless, bitter-tasting neurotoxin that is the plant's defense mechanism against pests. The green color is a visible cue that indicates higher solanine levels may be present, particularly in the skin and just beneath it. This is why properly storing potatoes in a cool, dark place is crucial to prevent both greening and the build-up of this harmful compound.

Symptoms of Solanine Poisoning

Symptoms of solanine poisoning can vary depending on the amount ingested, with most effects being gastrointestinal. These effects are often delayed, appearing anywhere from 2 to 10 hours after consumption. In more severe cases, neurological complications can arise, although this is rare and typically associated with very large ingestions.

Gastrointestinal Symptoms

Nausea and vomiting
Diarrhea
Abdominal pain or stomach cramps
Burning sensation in the throat

Neurological Symptoms

Headache
Dizziness
Fever
Confusion or delirium
Hallucinations
Weakness or paralysis
Dilated pupils
Slowed pulse and breathing

Safely Managing Green Potatoes

While discovering a green-tinged potato is concerning, it doesn't always require discarding the entire vegetable. For minor greening, peeling and trimming are often sufficient. However, if the green extends throughout the potato or if it tastes bitter, it is best to throw it away.

Proper Preparation and Handling

Inspect thoroughly: Before cooking, check potatoes for any green spots, soft patches, or sprouts. These areas contain the highest concentration of solanine.
Peel and trim: If the greening is localized and shallow, peel the potato generously. Cut away any sprouts and a deeper layer of the flesh beneath the green skin.
Taste test: Cooked potatoes with high solanine levels will have a distinctly bitter taste. If you detect this, do not continue eating and discard the potato immediately.
Do not use for children: Young children are more susceptible to solanine poisoning due to their smaller body mass. If you find greening, it is safest not to use the potato for meals intended for them.

Comparison of Green vs. Non-Green Potatoes

To highlight the key differences and risks, consider the following comparison of potatoes with and without greening.


Feature	Green Potato	Non-Green Potato
Chlorophyll	Present; gives green color.	Minimal or absent.
Solanine Content	Elevated levels, especially near the skin and sprouts.	Naturally low levels, safe for consumption.
Taste	Often bitter due to increased solanine.	Mild, earthy taste.
Storage Conditions	Exposed to light.	Stored in a cool, dark environment.
Health Risk	Potential for solanine poisoning if ingested in sufficient quantity.	Minimal risk associated with solanine.
Safety Action	Peel, trim, or discard. Do not eat if extensively green or bitter.	Generally safe to prepare and eat as normal.

Preventing Green Potatoes Through Proper Storage

Preventing the formation of solanine is straightforward with the right storage techniques. By limiting exposure to light and managing temperature, you can significantly prolong the shelf life of your potatoes and keep them safe for consumption.

Store in darkness: Always keep potatoes in a dark place, such as a pantry, cupboard, or basement. Light is the primary catalyst for both chlorophyll and solanine production.
Choose the right container: Use a paper bag, basket, or cardboard box that allows for good air circulation. Avoid storing potatoes in plastic bags, as they trap moisture, which promotes spoilage.
Find a cool spot: The ideal storage temperature for potatoes is between 45 and 50 degrees Fahrenheit (7 to 10 degrees Celsius). This is cooler than typical room temperature but warmer than a refrigerator, which can cause potatoes to sweeten and potentially increase solanine levels.
Avoid high heat: Keep potatoes away from heat-producing appliances like refrigerators or stoves, as warm temperatures can also encourage greening and sprouting.
Don't wash until ready: Do not wash potatoes before storing them. The dirt provides a small amount of protection from light exposure.

Conclusion

Green potatoes primarily cause solanine poisoning, a foodborne illness resulting from a natural toxin produced in the potato when it's exposed to light. While the green color itself (chlorophyll) is harmless, it serves as a clear warning sign that a potato may contain dangerously high levels of solanine. For minor greening, proper peeling and trimming can make a potato safe to eat, but it's crucial to discard any spud that is extensively green or tastes bitter. By practicing proper storage—keeping potatoes in a cool, dark, and well-ventilated area—you can effectively prevent the formation of solanine and ensure your potatoes remain safe and delicious. If you or someone you know suspects solanine poisoning, seek medical attention immediately.

First Aid for Solanine Poisoning

For mild symptoms, at-home recovery is common. However, for more severe cases or if symptoms persist, it is crucial to seek immediate medical help. A poison control center can provide direct instructions, but immediate emergency medical services should be contacted for severe cases. Treatment is typically supportive and aims to manage the symptoms.

Frequently Asked Questions

Solanine poisoning is a foodborne illness caused by ingesting high levels of solanine, a toxic glycoalkaloid found in potatoes, particularly those that have turned green or sprouted.

Potatoes turn green when exposed to light, which triggers the production of chlorophyll. This greening process also signals an increase in the potato's solanine content, a natural neurotoxin.

No, cooking does not effectively destroy solanine. Trimming and peeling the potato to remove green areas is necessary to reduce the toxin, and if it tastes bitter, it should be discarded entirely.

Early symptoms often include gastrointestinal distress such as nausea, vomiting, stomach cramps, and diarrhea, which may appear 2 to 10 hours after consumption.

To prevent greening, store potatoes in a cool, dark, and well-ventilated area, such as a pantry or basement. Avoid storing them in light or near heat-producing appliances.

For a small, superficial green spot, you can peel the potato and generously cut away the green section and surrounding flesh. If the potato is extensively green or tastes bitter, discard it to be safe.

Toxic doses of solanine can vary, but even small quantities in children can be problematic. A general rule is to avoid potatoes that are extensively green or taste bitter, as this indicates high solanine levels.

Yes, due to their smaller body mass, children are more susceptible to the effects of solanine poisoning. It is best to avoid serving them any potato with noticeable greening.