Are Green Potatoes and Tomato Leaves Deadly Poisonous?

By Emily Stackhouse [Public domain], via Wikimedia Commons

By Emily Stackhouse [Public domain], via Wikimedia Commons

Potatoes And Tomatoes And Deadly Nightshade

Two recent reports (1) that potato plants boost the chemical defenses in their leaves when their tubers are under attack (see Ref. 1 below) and (2) Why Tomato Leaves Smell “Grassy”? (see Ref. 2 below) reminded me of how fascinating the biochemistry is in solanaceous plants and, also, of a question I sometimes got when I was a botany professor.

Is it safe to eat green potatoes?

This question, I presume, was prompted by articles such as “Horrific Tales of Potatoes That Caused Mass Sickness and Even Death”.

Potatoes and tomatoes are the most well-known members of the plant family Solanaceae, a.k.a., the nightshade family.

Perhaps the most notorious member of this family, “deadly nightshade” (Atropa belladonna), is very toxic, even deadly.

(By the way, a really good book about this and other poisonous plants is Wicked Plants: The Weed That Killed Lincoln’s Mother and Other Botanical Atrocities, which was featured in a previous post.)

So, is it any wonder that people would expect the foliage of potatoes and tomatoes to also be very toxic?

And, indeed, both tomato leaves and potato tubers that have turned green due to exposure to light contain relatively small amounts of toxic compounds called alkaloids.

But according the “Curious Cook”, a.k.a., Harold McGee, the author of several books on the science of cooking (shown below), we may not have to worry too much about this.

Please see the links below for why:

Harold McGee on eating tomato leaves.

Harold McGee on green potatoes.

Though I wouldn’t eat a bunch of green potatoes, I may try a few tomato leaves in my next batch of pasta sauce.

Thanks Curious Cook!

Books by Harold McGee:

The classic that every cook should own: On Food and Cooking and, more recently, The Curious Cook.


1. Kumar, P., E. V. Ortiz, E. Garrido, K. Poveda, and G. Jander (2016) “Potato tuber herbivory increases resistance to aboveground lepidopteran herbivores.” Oecologia, doi: (Abstract)

2. Kunishima, M. et al. (2016) “Identification of (Z)-3:(E)-2-hexenal isomerases essential to the production of the leaf aldehyde in plants.” Journal of Biological Chemistry, doi: 10.1074/jbc.M116.726687 (Abstract)

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