Are Green Tomatoes Poisonous?

Are green tomatoes poisonous? And if so, do I have to cut off the green stalks of red tomatoes too?

Like potatoes, tomatoes also belong to the nightshade family. These can contain Solanum glycoalkaloids in their green plant parts. These natural pollutants help the plant to defend itself against pests and pathogens. In tomatoes they are called α-tomatine and dehydrotomatine, in potatoes it is the better known α-solanine.

Although the tomato’s solanum alkaloids are less toxic than those in potatoes, eating large amounts could cause headaches, stomach pains, nausea, and vomiting. We therefore advise against eating unripe green tomatoes. Children in particular should not eat unripe tomatoes due to their low body weight.

The content of glycoalkaloids is relatively high in unripe, green tomatoes, but negligibly low in ripe tomatoes. In this case, the green stalks can be eaten without any problems. Unripe tomatoes can be left to ripen at room temperature for a few days before eating, until the green spots disappear.

For the production of green chutneys and the like, the fruits of special green tomato varieties can be used instead of unripe tomatoes. These remain green even when ripe, but no longer contain any appreciable amounts of α-tomatin and dehydrotomatin.