There's something strange happening on the produce stand these days. There's color where it didn't used to be.
Plant growers are reaching back into the past for ancient varieties.
"The original carrots were either yellow or purple," said Mary Ruth McDonald of the University of Guelph in Ontario.
The original potatoes were purple, too. They're still being grown in the Peruvian Andes, and now purple potatoes and carrots are being grown in Ontario.
It's all part of a special research project by McDonald, a plant scientist.
"You get the greater benefits when they're purple all the way through," McDonald said. "There's more and more information on the health benefits of the different pigments available in plants."
The color matters because what makes them purple also makes them powerful: a plant-based chemical that becomes an anti-oxidant in the human body.
Anti-oxidants can neutralize harmful molecules, and that means eating colorful vegetables could help prevent disease.
At the University of Guelph, researchers have started one of the first clinical trials to test vegetables the way they way they test drugs.
Ratina Veluppilla is diabetic and has high cholesterol. He's volunteered to eat purple carrots in the name of science.
"Try eating them approximately the same time every day," an instructor tells him.
The study results won't be known for a while, but in the meantime purple vegetables are showing up on produce stands across Canada.