Stevia’s leaves provide natural sweet compounds and have traditionally been used in diabetes-related herbal practice.
The plant is Stevia rebaudiana, a small perennial native to parts of Paraguay and Brazil. Guaraní people called it ka’a he’ẽ, meaning “sweet herb,” and used its leaves for centuries to sweeten yerba mate and other preparations. The sweetness comes from steviol glycosides, chiefly stevioside and rebaudioside compounds.
Purified steviol glycosides can be hundreds of times sweeter than sucrose and contribute little or no energy because humans do not metabolize them like ordinary sugar. That makes stevia a common sugar substitute in reduced-calorie foods and drinks. In diabetes discussions, it is important to distinguish a low-calorie sweetener from a proven treatment: stevia may help replace sugar, but it is not a cure for diabetes.
Gymnema is a frequent mix-up because its leaves are also studied for blood-sugar management. Gymnema, however, is not the plant normally meant by the natural sweetener “stevia.”