The popularity of artificial sweeteners took off during the '60s. Diet Pepsi was introduced in 1964, and Sweet'N Low gave everyday sugar a run for its money. (Patio diet soda — Pepsi's first attempt at a diet cola — was even a client of the fictional Mad Men ad house Sterling Cooper.) Around the same time, Diet Delight was a popular low-cal fruit cocktail, which relied on the artificial sweetener cyclamate. But in 1969, seven million cases were pulled from grocery shelves when cyclamate was shown to cause bladder cancer in lab rats. The sweetener is still used in 55 countries worldwide.