Are Potato Leaves Poisonous?

  • By: SFUAA
  • Date: April 15, 2022
  • Time to read: 5 min.

If you’re like me, and you hate throwing out something that could be useful for food, you may have find yourself staring at your potato shoots and wondering if they’re safe to eat.

Sadly, it’s best to compost them or throw them out.

Potato leaves are poisonous if consumed. In fact, they contain a glycoalkoid called solanine that is toxic to humans and animals if ingested.

Sweet potato leaves are edible but can have a bitter taste, so it’s best to cook them first before eating. You should avoid consuming leaves from other species of potatoes such as white potatoes and purple potatoes because they contain solanine which can cause allergic reactions or gastrointestinal distress in humans.

Let’s talk a bit more about which parts of potatoes are and aren’t safe to eat.

Potato Plant | Photo 5227266 / Potato Leaf © Ganna Liutych |

The part of the potato that’s poisonous is the leaves and stems.

Potatoes are safe to eat, but it’s a good idea to avoid eating the leaves, stems and sprouts. The leaves and stems contain high concentrations of glycoalkaloids, naturally occurring compounds that can have toxic effects on humans and animals.

Glycoalkaloids are toxic to nerve cells. Solanine is one type of glycoalkaloid found in potato plants. It can cause symptoms ranging from gastrointestinal pain to paralysis if ingested in large quantities. Symptoms of solanine poisoning include difficulty breathing and a drop in blood pressure.

It’s also important to note that, according to Cornell University, cooking potatoes (and by extension their leaves, since we’re talking about the same poison) doesn’t get rid of the toxins that make them harmful.

The whole potato is toxic if it has sprouted.

Potatoes are also toxic if they’ve started sprouting, meaning they are now producing glycoalkaloids, which can be toxic to humans. If you see a potato has sprouted or has been exposed to sunlight, it’s best to toss it out.

The concentration of glycoalkaloids is much higher in potatoes that have sprouted than normal potatoes, meaning they may no longer be safe to eat, depending on the extent of the sprouting.

A report published on the National Institute of Environmental Health Sciences in the US states that a dose as small as 200mg can be a “minimum lethal dose” of glycoalkaloid for a 150lb adult. (That would be around 3-6mg/kg.)

Smaller doses can still cause poisonings in humans, however: it can cause acute gastroenteritis with symptoms like diarrhea, nausea, vomiting and stomach cramps. (The range for this would be 2-5mg/kg according to the report.)

However, potatoes may still be safe to eat if they’re cooked properly and eaten when they are still fresh and the sprouting on the potato is minimal.

You just need to remove the sprouts as well as the eyes of the potato around the sprout.

If you’re eating a potato that has unsafe amounts of solanine in it, you will notice the following:

  • Potatoes with an elevated amount of glycoalkaloids will have a bitter taste.
  • Potatoes with an extremely high amount will make your mouth and throat burn.

If you notice either of these, you should avoid eating the potato.

You shouldn’t eat potatoes if they’ve turned green.

If a potato has turned green, it means the chlorophyll levels have increased.

While chlorophyll is not toxic in itself, it is a sign that the potato has produced solanine, which is toxic. If a potato has turned green, or if you find a sprout on your potatoes, this means the levels of solanine have increased, making the potato no longer edible.

Potatoes naturally produce small amounts of solanine as part of their defense against pests and diseases, but when exposed to certain environmental conditions (namely light), they can produce more solanine than usual.

Green skinned potatoes also tend to be more bitter than usual because of their higher level of solanine and therefore are not as desirable for consumption – even in amounts below what would normally make you sick.

It’s not a huge deal in small amounts, however. For example, if you eat a green potato chip, you’re not likely to get significantly sick off of it – speaking from personal experience. They just may not taste as good.

Sweet Potato Leaves Are Safe to Eat

sweet potato vine
Sweet Potato Vine | Source: My Garden

There are a few things you should understand about sweet potato greens before deciding whether or not to eat them. For starters, sweet potatoes and Irish potatoes (also known as white potatoes) are different plants. The leaves from a true potato plant are poisonous; the leaves on the sweet potato vine are safe to eat.

Sweet potato leaves can be eaten raw or cooked. If you eat them raw, they will likely be bitter, so it’s better to cook them first. The flavor of cooked sweet potato greens is like that of spinach and Swiss chard—slightly sweet with an earthy undertone.

There are various ways to prepare these edible leaves including sautéing, boiling, or even steaming them to remove any bitterness. They can be eaten raw in a salad if you don’t mind the slightly bitter flavor, as it isn’t a sign that they’re harmful.

If you grow your own sweet potatoes, then consider yourself lucky if the vines produce enough leaves to harvest!

Takeaways: Potato Leaves Should be Aoided

In this article, we’ve cover some of the basics of why you should avoid eating potato leaves – and that if you are interested in eating some shoots why you should go for sweet potato greens instead.

Potato plant leaves are poisonous and should be avoided. Consuming large amounts could cause diarrhea, vomiting, or heart arrhythmia. In extreme cases, they may even cause airborne allergies that lead to skin reactions and respiratory issues.

Green potatoes contain solanine – a toxic substance – and can taste bitter. If you notice that your potatoes have started to sprout green shoots or turn green themselves, it is probably best to throw them away. You may have heard that these green potatoes are toxic — and you’re right!

The main poisonous chemical compound in potatoes is solanine; it gives the potato a bitter taste, so chances are good that you won’t eat enough for it to harm you. Still, as a rule of thumb: avoid eating potatoes with green spots or sprouts coming out of them.

Once they’ve gone through this transition phase from food staple to to growing plant, the potato will go from being edible to being toxic. Considering potatoes are relatively cheap (compared to hospital stays, anyway), it’s best not to take any chances.

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