1. It’s not just a sweetener. The plant genus Stevia includes more than 200 species of herbs and shrubs native to South America and mexico. Yet only two species, Stevia rebaudiana and Stevia phlebophylla, produce steviol glycosides in their leaves. These glycosides are the source of the plant’s sweet compounds.
2. But as a sweetener, it’s nothing new. Stevia rebaudiana has been used for more than 1,500 years by various indigenous peoples in South America both to treat diabetes, obesity and hypertension and to provide a sweetening effect for food and drink. Commercial use of stevia took off when sweeteners such as cyclamate and saccharin were identified as possible carcinogens. Japan became the first country to introduce commercial use of stevia in the early 1970s and still consumes more of it than any other nation. Stevia has been available for several decades in natural food stores but in recent years has increased greatly in popularity as a sweetener for processed foods. Today, stevia can be found in many u.S. supermarkets under a variety of brand names, such as Truvia and PureVia.
3. Why use stevia instead of sugar or other sweeteners? Stevia is significantly sweeter than table sugar, and comparable in sweetness to products such as aspartame, saccharin and sucralose, but it is metabolized differently. Stevia is perceived as sweet but does not cause a rise in blood glucose like sugar, making it a promising food for diabetics. It is a natural rather than an artificial sweetener.
4. How is stevia processed within the body? The glycosides in stevia are primarily known as rebaudioside (or rebiana) and stevioside. They have some bitterness associated with them and can be blended with other compounds to minimize this effect. Once consumed, the glycosides break down into steviol, which is simply excreted; and glucose, which is used by intestinal bacteria and does not go into the bloodstream. So eating foods sweetened with stevia means a sweet taste without added calories.
5. Can I grow stevia in Wisconsin? Stevia plants are not adapted to cold conditions but may be grown as annual plants in temperate regions (including in Wisconsin). However, growing plants from seed as an annual crop generally does not result in satisfactory results. Stem cuttings from mature stevia plants may be rooted and used to propagate stevia for growth in spring and summer.

Irwin Goldman is a professor and chair of the Department of Horticulture.

This article was posted in Five Things, Front List, Spring 2015 and tagged Grow Spring 2015, Horticulture, Irwin Goldman, Stevia.