In 1946, the Mexican muralist Diego Rivera invited Rina Lazo, one of his assistants, to have lunch at his home with him and his wife, the painter Frida Kahlo. Ms. Lazo was 23 and had been in Mexico for only a few months. She accepted.

That day, Kahlo served a traditional spicy Mexican meal — so spicy, in fact, that Ms. Lazo, who was from Guatemala, couldn’t enjoy it.

“Rina,” she later recalled Rivera saying, “if you do not learn how to eat spicy food, you will not be able to paint well.”

Ms. Lazo didn’t understand; what did food have to do with art?

Still, she saw Rivera as a mentor and took the comment to heart. It would be years before she would grasp what he meant, which she summed up in an essay in 2012 for the journal Crónicas, published by the National Autonomous University of Mexico:

“If you do not truly appreciate our food, our customs, our traditions, our culture, you will not be able to reflect in your painting what is most profound about the Mexican people.”