A friend recently asked me about stevia, which is a naturally sweet plant native to Central and South America. In the United States, stevia has been marketed as a dietary supplement for years because, until recently, it did not have approval as for use as a food ingredient. However, a purified extract of stevia, rebaudioside A (trade name Rebiana), was approved by the U.S. Food and Drug Administration (FDA) in December 2008 as a general purpose sweetener for use in foods. Truvia is the consumer brand for a food sweetener made from Rebiana - being marketed by Cargill and Coca-Cola. PureVia is the consumer brand for Whole Earth Sweetener Company's Rebiana, which is a supplier to PepsiCo. Both Truvia and PureVia are available as sugar packets, similar to other non-nutritive sweeteners. Several low-calorie and calorie-reduced beverages have been launched under Sprite, Odwalla, SoBe and Tropicana brands.
The plant Stevia rebaudiana Bertoni is a member of the Compositae (astor or sunflower) family, which includes marigolds, dandelions, chrysanthemums, zinnias, artichokes, lettuce and endive. The sweetness in stevia comes from glycosides (technically a molecule comprised of a sugar attached to another component) that are natural constituents of the plant's leaves. In fact, stevia leaves contain at least ten different glycosides, the major ones being stevioside and rebaudioside A. Of note, the FDA food ingredient approval is for the purified extract of rebaudioside A; however, dietary supplement versions of stevia may contain other glycosides.
The regulatory history of stevia is an interesting tale. Steviol glycosides are used to sweeten a number of foods in China, Japan, and South America. Also, Stevia leaves are used to prepare sweetened tea in numerous countries. However, concerns about safety prompted the FDA to ban imports of stevia from 1991 to 1994, which ruled the herbal sweetener an "unsafe food additive." The Dietary Supplement Health and Education Act (DSHEA) of 1994 formed the impetus for the FDA to permit stevia to be marketed as a dietary supplement (not as a food additive). In 1999, the European Commission banned the use of stevia in foods marketed in the European Union. But the World Health Organization published an extensive literature review of stevioside and rebaudioside A in 2006 that concluded stevioside and rebaudioside A are not toxic or carcinogenic at levels consumed by humans. The report also noted that stevioside has shown some evidence of pharmacological effects in patients with hypertension or with type-2 diabetes but indicated more research is needed. And the potential therapeutic aspects may play into a future regulatory challenge. According to a March 16, 2009, Food Product Design article, "A Citizen’s Petition was filed with FDA in late 2008 to prevent the addition of steviol glycosides to foods because of the drug status alleged for the sweeteners. [The] FDA is also attempting to implement recent legislation that more broadly prohibits the addition of drugs to foods. FDA’s resolutions of these two matters could impact the future food uses of steviol glycosides."
In the mean time, the approval of Rebiana for use as a general purpose sweetener offers another non-nutritive sweetener option for U.S. consumers.