It's commonly believed that the leaves on a tomato plant are poisonous, so we often discard or avoid them. But is that really true, or simply an exaggerated tale that's managed to stick around? Are we wasting a perfectly edible part of this plant?
Tomato Leaves and Their Poisonous Rap
Wariness about tomato leaves stems, in large part, from the plant's status as part of the nightshade family. While this family plays host to a variety of toxic, "deadly" plants, the tomato is not one of them, despite containing the alkaloids tomatine and solanine.
As with many other plants and vegetables, it's all about that quantity that's consumed. There are plenty of foods that, when eaten in high quantities, can prove harmful. For tomato leaves, this would require eating at least a pound and a half — an exceptionally large amount.
→ Read more: A Short History of the Ostensibly Deadly Nightshade
Tomato leaves have a very pungent scent, which can certainly be off-putting to some, although not an indicator that they're harmful. Additionally, we don't see or hear about tomato leaves very often. Tomato foliage isn't commercially sold, nor is it seen in recipes, but that omission hardly means they're poisonous.
Where's the Evidence?
Is there actually any hard evidence to back this claim up? Not according to Harold McGee in his Curious Cook column for The New York Times, who cites there's simply little evidence to support the belief that tomato leaves are poisonous.
I talked to Craig LeHoullier, author of the book Epic Tomatoes, and like Harold McGee, he agrees that much of what we hear about tomato leaves is anecdotal. He suggests that part of the skittishness around tomato leaves stems from the oft-repeated presence of solanine, the alkaloid also found in potatoes. "Perhaps the twitchiness about consuming tomato foliage will pass away with time, and maybe what happens next is dried tomato foliage in a jar next to the turmeric, or in fresh grocery packets alongside thyme."
Immature, green tomatoes also contain both solanine and tomatine, although the levels decrease as the tomato matures. Even so, we happily batter and fry up these unripe green tomatoes without question. Former Chez Panisse chef Paul Bertolli even includes the leaves in his tomato sauce to add some punch to the flavor. While the leaves might not have the sweet, ripe taste of a summer beefsteak tomato, they do, in fact, have a tomato flavor.
Have you ever cooked with tomato leaves? How did you use them?