How tomatoes, once thought to be toxic, became a globally beloved food

It's the base of a fast food staple and typically slathered on pasta, but the humble tomato wasn't always so popular.

When it was introduced to Italy by Spanish conquistadors nearly five centuries ago, few wanted to touch it. Some even considered it poisonous. 

Now, it's among the most widely eaten foods in the world, despite its bad rap.

"The supermarket tomato routinely finishes dead last in food satisfaction surveys. It's even become the avatar for tasteless, corporate food," said William Alexander, author of Ten Tomatoes that Changed the World, in an interview on CBC Radio's The Sunday Magazine.

The crimson fruit — better known as a vegetable following an 1893 U.S. Supreme Court ruling — is used in dishes around the world and has single handedly defined the cuisine of Italy. And tomato sauce played a crucial role in making pizza a globally loved dish.

But Alexander likens the produce to late comedian Rodney Dangerfield.

"It gets no respect," he said, with a laugh.

Ignored for centuries

Much like the vines they grow on, the tomato's history is full of twists and turns.

As Alexander explains it, tomatoes were originally brought to Italy from the Americas by Spanish colonists sometime around 1530, and they weren't well received.

"We actually have a record of the day that a basket of this strange new fruit arrives at the Pisa palace of no less than Cosimo de Medici, who you'd think would be just a great person to get these," the author said.

Medici, part of the wealthy Italian banking family, founded the botanical gardens in Florence and had already been growing maize, a crop from the new world.

But people in the room turned up their noses. "They were not served for dinner that night, they were not served for dinner the next night, and they were not served for dinner for 300 years," said Alexander.

From pig lard to marinara

There are a few theories about why the tomatoes didn't catch on.

First, Alexander says, there was nothing like the tomato in Italian cooking at the time. 

Secondly, botanists correctly identified tomatoes as a nightshade. Some species in the nightshade family, a group of flowering plants, are highly toxic. But given people in the region were already eating eggplant and peppers — also nightshades — Alexander is skeptical of that theory.

The theory he most favours? The work of Galen of Pergamon, a second-century Greek physician who promoted the belief that certain foods influenced the four "humors," had once again gained prominence around the same time. While Galen wouldn't have known about tomatoes, proponents of humoral medicine believed them to be wet and cold, and inherently unhealthy.

As for the beloved combination of pasta and marinara sauce, Alexander says pigs may be to thank.

For a long time, pasta — which originated in Naples — was a street food eaten by hand. Traditionally, it was covered in pig's lard, but it's believed that cooks started topping it with tomato sauce because the preferred swine species for making prosciutto, also known as Parma ham, was changing.

"In the middle 1800s, the black pigs that had been used for Parma ham started to get replaced by three other types of pigs that grew faster [and] made better ham, but the lard was not as good," said Alexander.

"So one theory is that people eating pasta in the streets started to look for a different topping to put on the pasta."

Thomas Jefferson's tomatoes

By the 1800s, tomatoes were also beginning to gain popularity in North America. According to legend, New Jersey farmer Col. Robert Gibbon Johnson is largely responsible.

"The story goes that tomatoes were considered inedible until he stood on the courthouse steps … in 1820, I think it was, and ate an entire bucket of the things," said Alexander.

However, it's believed that former U.S. president Thomas Jefferson had been growing and serving his own tomatoes since at least the turn of the 19th century.

The fruits were also already enjoyed in the southern U.S., likely brought to the country by enslaved cooks who had prepared with them in the Caribbean. 

But despite Johnson's alleged efforts, people in the north didn't get into the trend until doctors of the time began touting the tomato as a health food. Some entrepreneurs even sold tomatoes in pill form, Alexander said.

"This one doctor gave a talk to his medical students that got published in like 200 newspapers talking about all their health properties. And this was the time when the United States was becoming very health-conscious, mainly because cholera was coming," he said. 

Love for tomatoes continues

Alexander says that the future looks bright for tomatoes — especially as more people look to grow their own.

"If there was any kind of a faintest silver lining to COVID, it's that many people started growing their own fruits [and] vegetables — and tomatoes were number one," he said.

When asked to name his favourite tomato, Alexander pointed to the purple Cherokee, an heirloom beefsteak variety.

Picked fresh from the garden and served still warm from the sun, he says it's best enjoyed on bread.

"Slice it, cook up some bacon, get out the mayonnaise and make the world's best sandwich: a BLT," he said.

"You cannot beat it."

Written by Jason Vermes. Produced by Sarah-Joyce Battersby and Andrea Hoang.