Containing only 1/8 calorie per teaspoon, this artificial sweetener is said to be 300 times sweeter than sugar. Saccharin was discovered by accident in the late 1800s by scientists at Johns Hopkins University. Though it's widely used to sweeten a multitude of commercial foods and beverages — as well as in the home — some find that it has a decidedly bitter aftertaste. This unpleasant effect is particularly noticeable when a food sweetened with saccharin is heated. Saccharin is available in both powdered and liquid forms in supermarkets. It has been the center of controversy during the last few decades because of its reported possible carcinogenic effects. Because the issue is still being researched, the FDA requires that saccharin products carry a warning label to that effect. See also acesulfame-K; alitame; aspartame, sucralose.