Tomatoes Were Once Believed to Be Poisonous in Europe

When tomatoes were brought to Europe from the Americas in the 16th century, wealthy Europeans initially avoided eating them. They ate from pewter plates, and the acid in tomatoes leached lead from the plates — causing lead poisoning. The poor, who ate from wooden plates, had no such problem, so the "tomato is poisonous" belief persisted among the upper class for over a century.

Source: The Tomato in America — Andrew F. Smith