Stevia and sugar are two kinds of nutritional sweeteners found in sodas and other sweet beverages, baked goods, and many processed and packaged foods. While sugar, also known as sucrose or table sugar, comes from the sugar beet or sugar cane plant and has long been used as a sweetener, stevia is relatively new to the market. It is sold under several brand names, comes from the Stevia rebaudiana plant, and is hundreds of times sweeter than sugar. Both are marketed as natural sweeteners as both are made from plants, but the effects of stevia and sugar in the body may not be identical.
Sugar is used as a food additive or naturally occurring in food in many forms. Sucrose, dextrose, fructose, maltodextrin, and high-fructose corn syrup are only a few examples. Sucrose is a dissacharide, meaning that it is formed by two simple sugars: glucose and fructose. It is made from sugar beets or sugar cane. Sugar cane, grown in tropical climates, accounts for more than two-thirds of production. Stevia and sugar are often compared for the calories they add to food, as sugar supplies 4 calories (17 kilojoules) per gram, or 16 calories per teaspoon and 48 calories per tablespoon.
Like table sugar, stevia is used commercially as a food additive to sweeten foods like soda and baked goods. Stevia rebaudiana is only one of 240 plants in the stevia genus. It is also known as sweetleaf or sugarleaf. The sweetness comes from an extract from the leaf known as steviol glycoside or rebaudioside A that is up to 300 times sweeter than sucrose.
Though it has been in use in many countries for centuries — it is particularly popular in southeast Asia — it was only approved in its current form in the United States in 2008. It is largely banned in Europe due to concerns about potential toxins contained within. Extracted by drying the leaves and using crystallization to separate the rebaudioside A, stevia contributes no calories to foods or beverages.
A notable difference between stevia and sugar, aside from the fact that one contains calories and the other does not, is that stevia has been found not to cause the same spikes in blood glucose. Consuming table sugar causes a temporary rise in blood sugar levels, leading the body to release insulin to take up and store this sugar. Since stevia consumption has been shown to cause little to no rise in blood sugar, it has been recommended to those who are diabetic, insulin-sensitive, or on low-carbohydrate diets.