Stevia is a perennial shrub belonging to the Aster family which is indigenous to the northern regions of South America. It grows up to a meter tall and has 2-3 cm long leaves. It is still found growing wild in the highlands of the Amambay and Iguacu districts (a border area between Brazil and Paraguay), however it is now commercially grown in many parts of Brazil, Paraguay, Uruguay, Central America, Israel, Thailand and China. For hundreds of years, indigenous peoples in Brazil and Paraguay have used the leaves of Stevia as a sweetener. The Guarani Indians of Paraguay call it Kaa jheé and have used it to sweeten their Yerba Mate tea for centuries.⁽¹⁾ They have also used it to sweeten other medicinal teas and foods as well as use it medicinally as a cardiotonic, for obesity, hypertension, heartburn, and to help lower uric acid levels.⁽²⁾

Europeans first learned about Stevia in the Sixteenth Century when Spanish Conquistadors sent word to Spain that the natives of South America had used the plant to sweeten herbal tea since ancient times. Western interest in Stevia began around the turn of the twentieth Century when researchers in Brazil started hearing about a plant with leaves so sweet that just one leaf would sweeten a whole gourd full of bitter Mate tea. It was first studied by Paraguayan botanist, Moises S. Bertoni in 1899 who wrote some of the earliest articles on Stevia in the early 1900's. The constituents responsible for Stevia's sweetness were documented in 1931 when 8 novel phytochemicals called glycosides were discovered and named.⁽³⁾ Of these eight glycosides, one called Stevioside is considered the "sweetest" being tested at approximately 300 times sweeter than saccharose.⁽⁴⁾ Stevioside, making up to 6% to 18% of the constituents of Stevia leaves, is also the most prevalent glycoside present in the leaves.^{(4, 5)} Stevioside is considered 300 times sweeter than sucrose at 0.4% sucrose concentration, 150 times sweeter at 4% sucrose and 100 times sweeter at 10% sucrose concentration.⁽⁵⁾ Because of the great interest in Stevia and Stevioside being a natural sweetener, there have been many studies on it, including toxicological studies. Stevioside has been found to be nontoxic in acute toxicity studies with rats, rabbits, guinea pigs and fowl being excreted without structural modification.⁽⁵⁾ It has also been shown not to be mutagenic, genotoxic nor did it produce effects on fertility.⁽⁵⁾

For nearly 20 years, Japanese and Brazilian consumers by the millions have used Stevia extracts as a safe, natural, non-caloric sweetener where it is approved as a food additive. Japan is the largest consumer of Stevia leaves and extracts in the world where it is used to sweeten everything from soy sauce, pickles, and confections to soft drinks. Even multi-national giants like Coca Cola and Beatrice Foods use Stevia extracts to sweeten foods (as a replacement for Nutra Sweet and saccharin) for sale in Japan, Brazil and other countries where it is approved as a food additive. Not so in the United States however, where Stevia is specifically prohibited to be used as a sweetener or as a food additive. Why? Noncaloric sweeteners are a big business in the U.S. and the national sweetener giants have been successful in lobbying the FDA to prevent this all natural, inexpensive and non-patentable sweetener from being used to replace their patented, synthetic, more expensive sweetener products. Today, Stevia products and Steviosol extracts may only be sold in the U.S. as foods and food supplements, not as food additives. In fact, in 1991, the FDA had even banned all imports of Stevia into the country⁽⁶⁾ and this political move with it's obvious monetary ties to the sweetener industries like Nutra Sweet, who stood to lose a lot, created a huge public outcry in the natural products industry. The import ban was lifted in 1995 after much lobbying led by the American Herbal Products Association, which allowed Stevia to be sold as a dietary supplement under new legislation passed called the Dietary Supplement Health and Education Act of 1994. The FDA, in one of their more politically incorrect debacles of this century, has ruled that Stevia is presumed safe as a dietary supplement, but is considered unsafe as a food additive today - continuing to protect profit margins of the sweetener giants like Nutra Sweet. In the words of Rob McCaleb, president of the Herb Research Foundation and a newly appointed member of the President's Commission on Dietary Supplements, "The FDA may have painted itself into a corner on this one. Its policy simply makes no sense."⁽⁷⁾

In addition to being a sweetener, in Brazilian herbal medicine Stevia is considered hypoglycemic, hypotensive, diuretic and tonic used in cases of diabetes, hypertension and high blood pressure, as well as a cardiotonic.^(8-11) American practitioners are using Stevia in much the same manner.⁽¹²⁾ Several clinical studies validate these uses. A crude extract of Stevia demonstrated hypotensive activity in a 1996 clinical study with rats showing that "at dosages higher than used for sweetening purposes, [Stevia Extract] is a vasodilator agent in normo- and hypertensive animals."⁽¹³⁾ Several earlier studies on both Stevia extracts as well as isolated glycosides demonstrated this hypotensive action as well as a diuretic action.^{(14, 15)} The same Brazilian scientist recorded Stevioside's ability to lower systemic blood pressure in rats in 1991.⁽¹⁶⁾ Another Brazilian research group demonstrated that water extracts of Stevia leaves had a hypoglycemic effect and increased glucose tolerance in humans reporting that it: "significantly decreased plasma glucose levels during the test and after overnight fasting in all volunteers."⁽¹⁷⁾ Another team of scientists tested the hypoglycemic effects of the individual glycosides in Stevia and attributed its effect on glucose production to the glycosides, Steviol, isosteviol and glucosilsteviol.⁽¹⁸⁾ The main sweetening glycoside, Stevioside, did not produce this effect.⁽¹⁸⁾ It effects and uses as a cardiotonic to normalize blood pressure levels, regulate heartbeat, and for other cardiopulmonary indications were first reported in rat studies in 1978.^{(19, 20)}
 

Footnotes:

1. Oddone, Blas. 1991. Personal information collected from local Shamans in Paraguay.
2. Lewis, Walter, H. 1992, Econ Bot., 46(3), 336
3. Bridel, M., et.al., 1931. J. Pharm Chim 14: 99
4. Samuelsson, Gunnar. 1992. Drugs of Natural Origin, Swedish Pharmaceutical Press: Stockholm, Sweden.
5. Lung. A. and Foster, S. 1996. Encyclopedia of Common Natural Ingredients, Wiley & Sons: New York, NY. (33)
6. FDA Import Alert No 45-06 (May 17, 1991)
7. Blumenthal, Mark, 1996. "Perspectives on FDA's New Stevia Policy, After four years, the agency lifts its ban - but only partially" Whole Foods Magazine, February 1996.
8. Bernardes, Antonio, 1984 A Pocketbook of Brazilian Herbs, A Shogun Editora e Arta Ltda: Rio de Janeiro, Brazil. (3)
9. Cruz, G.L. 1995. Dicionario Das Plantas Uteis Do Brasil, 5^th ed., Bertrand: Rio de Janeiro, Brazil (9)
10. de Almeida, E.R., 1993. Plantas Medicinais Brasileiras, Conhecimentos Populares E Cientificos. Hemus Editora Ltda.: Sau Paulo, Brazil.(74)
11. Sousa, M.P, Matos, M.E., et al., 1991. Constituintes Quimicos Ativos de Planta Medicinais Brasileiras.Laboratorio de Produtos Naturais: Fortaleza, Brasil. (90)
12. Schwontkowski, Dr. Donna, 1993. HERBS OF THE AMAZON, Traditional and Common Uses, Science Student BrainTrust Publishing, Utah. (8)
13. Melis, MS. 1996. A crude extract of Stevia rebaudiana increase the renal plasma flow of normal and hypertensive rats. Braz J Med Biol Res May 29(5): 669-675
14. Melis MS. Chronic administration of aqueous extract of Stevia rebaudiana in rats: renal effects. JEthnopharmacol, 1995 Jul 28
15. Melis, MS. 1992. Stevioside effect on renal function of normal and hypertensive rats. J Ethnopharmacol, Jun 1992
16. Melis MS, et al., 1991. Effect of calcium and verapamil on renal function of rats during treatment with stevioside. J Ethnopharmacol, Jul 1991
17. Curi R, et al. 1986. Effect of Stevia rebaudiana on glucose tolerance in normal adult humans. Braz J Med Biol Res
18. Yamamoto NS, et al. Effect of steviol and its structural analogues on glucose production and oxygen uptake in rat renal tubules. Experientia, 1985 Jan 15
19. Boeckh, E.M.A., et al. 1978. Avaliacao clinica do efeito cronico do edulcorante natural Stevia rebaudiana Bertoni sobre o teste de tolerancia a glicose, parametros clinicos e eletrocardiograficos em individuos normais. V Simposio de Plantas Medicinais do Brasil, p.208 September 4-6, 1978, Sao Paulo-SP, Brazil.
20. Humbolt G., et al., 1978 Steviosideo: efeitos cardio-circulatorios em ratos V Simposio de Plantas Medicinais do Brasil, p.208 September 4-6, 1978, Sao Paulo-SP, Brazil.

REFERENCED QUOTES ON STEVIA

2. "Stevia has been used by South American Indians as a sweetening agent. It is helpful for weight loss programs because it can satisfy sugar cravings and is low in calories. It is supportive to the pancreas and has been used in treatment of diabetes, hypertension and infections."

3. "ACTIONS: Sweetening agent, Satisfies sweet cravings, Adjunct for diabetes and hypertension treatment. TRADITIONAL USE: Long used by the Guarani Indian tribe to sweeten many foods. Recognized for its incredible sweetening power, helpful when used as auxiliary to weight loss programs because it is low in calories. Stevia, a well know sweetener to Brazil, is believed to produce positive results in the treatment of diabetes and hypertension. Has been used in the treatment of diabetes, hypertension and infections. MERIDIAN INDICATIONS: Benefits digestion, Increases Stomach Yang. EAV POINTS: Pancreas, Circulation, Triple Warmer"

8. "Stevia is a small bush which grows near Brazil's southern border, on the frontier with Paraguay, It contains Stevisoid, a natural sweetener. It is 300 times as sweet as sugar, yet is not absorbed by the body and contains hardly any calories. Brazilian uses and folklore: Stevia has long been used by the Guarani Indian tribe to sweeten other herbal teas and foods. The plant was first studied scientifically in 1899 by Paraguayan botanist Moises S. Bertoni, who recognized the plants incredible sweetening power. He suggested that Stevisoid might substitute saccarhine as a sweetening agent being completely non-toxic. In Rio de Janeiro studies on Stevia are continuing and it is considered to be the sweetener of the future. Stevia is grown in the interior of Sao Paulo. In the city of Birigui the plant is so popular that the tea made from it is sold at almost all bars and restaurants. Milkshakes, juices and coffee are sweetened with Stevia. The inhabitants in this little town speak of the wonders of Stevia and the positive results it has given in cases of diabetes, hypertension and infections. Stevia is considered to be a great help in weight loss programs because it is very low in calories and its sweetness is so concentrated. Chewing a few leaves of Stevia will satisfy anyone's sweet tooth, and the shredded leaves are an excellent substitute for sugar in cooking. Uses: Natural herbal sweetener; useful in treating the symptoms of diabetes, high blood pressure, infections."  

Raintree Nutrition offers Stevia by the ounce and the pound and is an ingredient in several Amazon Support Formulas. Both are available by mailorder through The Rainforest Market