Stevia - The Natural Alternative to Artificial Zero Calorie Sweeteners

Stevia plant material, extract, and its isolates, stevioside and rebaudioside A, are accepted natural health products and food additives in many parts of the world (6), and have been used by the Guarani Paraguayan Indians, Mestizos and others as a sweetener for bitter drinks for centuries (5). Stevia is a genus of approximately 150 herbs and shrubs, and is well known for its sweet leaves. The plant leaves contain the glycoside stevioside, which has no calories and is 300 times sweeter than sugar.

Stevia extract and stevioside seem to decrease blood pressure, according to human and animal studies. In a two-year study of patients with mild hypertension, oral stevioside significantly decreased diastolic and systolic blood pressure. Several other studies have found similar effects on blood pressure (3).

Enjoy the sweetness without the calories

Stevia extracts have been used for the treatment of type 2 diabetes in countries including Japan and Brazil. Researchers at the C, Aarhus University Hospital in Denmark studied the acute effects of stevioside in type 2 diabetic patients. They hypothesized that supplementation with stevioside to a test meal causes a reduction in blood glucose. They found that stevioside reduces postprandial blood glucose levels in type 2 diabetic patients, indicating that it shows promise in the treatment of type 2 diabetes. (4). Another earlier study examined the effect of aqueous extracts of Stevia rebaudiana leaves on a glucose tolerance test in 16 normal volunteers. The extract significantly decreased plasma glucose levels in all volunteers (2).

The U.S. Food and Drug Administration has labelled stevia an “unsafe food additive”. Stevia can be marketed legally as a dietary ingredient in dietary supplements, but manufacturers are prohibited from labelling it as a sweetener or flavoring agent. A document on the FDA website states, “available toxicological information on stevia is inadequate to demonstrate its safety as a food additive or to affirm its status as GRAS” (7).

In 2006, the World Health Organization evaluated recent human and animal studies of stevioside and steviols, and concluded “stevioside and rebaudioside A are not genotoxic in-vitro or in-vivo…” They also did not find any evidence that stevia is carcinogenic, and noted that there is some evidence supporting stevioside’s uses for hypertension and type 2 diabetes. However, more research needs to be completed to determine the therapeutic doses (1).

Stevia has been approved as a dietary supplement in Canada, Australia, New Zealand, Japan, and South American countries, but is banned for use in food in the European Union, Singapore, and Hong Kong.
Coca-Cola and Cargill have developed rebania, a patent-pending, calorie free sweetener derived from stevia, which they plan to have approved in the United States by 2009, and will also market it to 12 other countries that have approved stevia as a food additive (8).

References

1. Benford et al. (2006). Safety Evaluation of Certain Food Additives: Steviol Glycosides. WHO Food Additives Series; 54:140.
2. Curi R, Alvarez M, Bazotte RB, et al, 'Effect of Stevia rebaudiana on glucose tolerance in normal adult humans', Braz J Med Biol Res 1986;19(6):771-4.
3. Hsieh et al. (2003). Efficacy and tolerability of oral stevioside in patients with mild hypertention: a two-year randomized, placebo-controlled study. Clin Ther; (25(1): 2797-808.
4. Gregersen et al. (2004). Antihyperglycemic effects of stevioside in type 2 diabetic subjects. Metabolism; 53(1):73-76.
5. Phytotherapies.org (2000). Monograph: Stevia rebaudiana.
   Available from http://www.phytotherapies.org/monograph_detail.cfm?id=115
6. Natural Health Products Directorate. (2006). Guidelines for Use of Stevia in Natural Health Products. NHPD Monthly Communique; 2(1):2-5.
7. U.S Food and Drug Adminstration (1996; 2005). “Automatic detention of stevia leaves, extract of stevia leaves, and food containing stevia”. Available online from http://www.fda.gov/ora/fiars/ora_import_ia4506.html [Cited Aug.31, 2007].
8. Wikipedia.com. Article on Stevia. Available online from http://en.wikipedia.org/wiki/Stevia#_note-WHO [Cited Aug.31, 2007].