Green Potatoes: Harmless or Poisonous?

Medically Reviewed on 7/28/2022
Green Potatoes: Harmless or Poisonous
Learn about whether eating green potatoes is safe or harmful to your health and what you can do to prevent greening

If your potatoes have turned green, you may be unsure whether to keep them or throw them out. 

Learn what causes potatoes to turn green, how they can affect your health, and what you can do to prevent greening.

What causes potatoes to turn green?

When potatoes are exposed to direct sunlight, they naturally start to turn green.

This greening is due to chlorophyll biosynthesis, a process that enables plants to turn sunlight, carbon dioxide, and water into sugars and oxygen, and the simultaneous production of a potentially harmful and toxic neurotoxin called solanine.

A high level of solanine causes potatoes to taste bitter, and its consumption can even lead to health dangers such as digestive issues and neurological problems.

Are green potatoes safe to eat?

According to the USDA, potatoes with a high concentration of solanine can be harmful if eaten in large quantities.

Solanine can damage cell membranes and interfere with enzymes responsible for breaking down neurotransmitters in the brain. 

Excess consumption of solanine can lead to symptoms such as:

How much solanine is dangerous?

It is difficult to determine exactly how much solanine in green potatoes will cause negative health effects.

Based on case reports and a few toxicology studies, the toxic levels of solanine are about 0.01 ounce for a 200-pound person.

Studies estimate that ingesting 0.9 mg per pound of body weight is enough to cause symptoms. However, 0.6 mg of solanine could be enough to make children or low-weight adults ill.

How can I prevent my potatoes from turning green?

Careful handling and proper storage can prevent potatoes from turning green.

  • Buying: Before buying potatoes from the store, make sure they do not have any green spots.
  • Storing: To prevent potatoes from turning green or sprouting too soon, store them away from direct sunlight in a cool pantry or a cabinet. Make sure to keep the potatoes away from heat and avoid keeping them next to ripening produce.

Can peeling or heating potatoes reduce toxin levels?

Since the highest concentration of solanine is in the potato skin and sprouts, it is possible to remove the skin and reduce the number of toxins. 

Always use caution if small areas of greening are found on potatoes. Removing the green portions by simply cutting them out will eliminate most of the toxins. Because solanine is produced in higher concentrations around the eyes and sprouts of potatoes, they should be removed as well.

Boiling, frying, baking, or other cooking methods do not destroy solanine. Therefore, it is best to simply discard potatoes with large areas that have turned green.

Are potatoes good for you?

Potatoes are inexpensive, versatile, and nutritious. A medium-sized potato (5.3 ounces) contains the following nutrients:

  • Calories: 110 calories 
  • Potassium: 18% of the daily recommended value 
  • Vitamin C: 45% of the daily recommended value 
  • Fiber8% of the daily recommended value 
  • Vitamin B6: 10% of the daily recommended value 
  • Iron: 6% of the daily recommended value


According to the USDA, there is no difference between a “portion” and a “serving.” See Answer

Health Solutions From Our Sponsors

Medically Reviewed on 7/28/2022
Image Source: iStock image

Are green potatoes dangerous?

Green Potatoes: The Problem.

What to Know About Green Potatoes.