Stevia originally came from the rain forests of Brazil and Paraguay, But, now we can also find Stevia in South East Asia.
Stevia is believed to benefit people suffered from  high blood pressure and help control glucose levels. Consequently, it
has been used as a non-sugar sweetener for food and drinks and as remedy for diabetes [1]

Active Ingredients of Stevia
Stevia leave contains various glycosides including stevoside. Stevoside is a natural sweetener. It is a a diterpenic
carboxylic alcohol with three glucose molecules [12]

Stevoside is about 100-200 times sweeter than sugar. Some doctors may use it to reduce blood pressure and help
patients suffered from diabetes [2,3].

The sterol fraction of Stevia rebaudiana Bertoni contains, essentially, the following sterols: stigmasterol (45,8%), beta-
sitosterol (39,4%) and campesterol (13,1%). [7]


Physiological and pharmacological experiments have suggested that stevioside from the leaves of Stevia rebaudiana acts
as a typical systemic vasodilator.

CELL CULTURE Researchers found that stevioside (from Stevia rebaudiana leaves) mediated vasorelexation effect
through Ca(2+) influx inhibition. [11]

RATS Melis MS. demonstrated that stevioside (from Stevia rebaudiana leaves) provoked hypotension (blood pressure
lowering effect), diuresis and natriuresis in both the normal and hypertensive rats.  Normal rats presented an increase in
renal plasma flow (RPF) and glomerular filtration rate (GFR) constant following stevioside administration. The last effect
is in part due to vasodilation of both the afferent and efferent arterioles. [8]

Chan P et al demonstrated the blood pressure lowering effect of stevioside (from Stevia rebaudiana leaves) on both
systolic and diastolic blood pressure of rats. It is in a dose-proportional fashion. They found no significant changes in
serum dopamine, norepinephrine and epinephrine levels 60 min after intravenous injection of stevioside 100 mg/kg in
anesthetized rats. [10]

Drinking of 0.1% stevioside (from Stevia rebaudiana) solution in mature spontaneously hypertensive rats could have
antihypertensive (blood pressure lowering) effect and also prevented hypertension (high blood pressure) in immature
spontaneously hypertensive rats. [12]
Stevioside (from Stevia rebaudiana leaves) caused vasorelaxation via an inhibition of Ca(2+) influx into the blood vessel
in a study of normal rats. [11]

DOG Stevioside (from the leaves of Stevia rebaudiana) also showed significant hypotensive effects in renal hypertensive
dogs, in a dose-dependent manner and its hypotensive (blood pressure lowering effect) mechanism may be probably
due to inhibition of the Ca(2+) influx. [13]

HUMAN Chan P et al demonstrated the antihypertensive (blood pressure lowering) effect of stevioside (from Stevia
rebaudiana leaves) in a 3-month, multi-center, randomized, double-blinded, placebo-controlled study. [9]

A 2-year study of 168 patients suffered from hypertension (aged 20-75) demonstrated that oral stevioside (from Stevia
rebaudiana Bertoni) decreased systolic and diastolic blood pressure without significant adverse effects [14]

Stevia extracts may benefit people at risk of diabetes, as they may help to control blood glucose levels. However, users
must be careful, if they are also on anti-diabetic medications. In 1986, Curi R et al, Universidade de Maringa, Brasil,
demonstrated that aqueous extracts of Stevia rebaudiana leaves could increase glucose tolerance in a study of 16
healthy human subjects. [15]

About 14 years later, Jeppesen PB and co-workers at Aarhus University Hospital, Denmark demonstrated that stevioside
and steviol (from stevia) stimulated insulin secretion via a direct action on beta cells. The results suggested that the
stevia may be beneficial to people suffered from type 2 diabetes mellitus. [16] In 2002, Jeppesen PB et al reported that
stevioside (from stevia) had antihyperglycaemic, insulinotropic, and glucagonostatic activities from a study of type 2
diabetic rat. [17] In 2004, Jeppesen PB et al finally studied the anti-hyperglycaemic properties of stevioside (from stevia)
in human subjects. They recruited 12 patients suffered from Type 2 diabetes and successfully demonstrated that
stevioside reduces postprandial blood glucose levels in the patients. [18]

On the other hand, Chen TH and co-workers found that stevioside (from stevia) was able to regulate blood glucose levels
by enhancing not only insulin secretion, but also insulin utilization in insulin-deficient rats; the latter was due to decreased
phosphoenol pyruvate carboxykinase gene expression in rat liver by stevioside's action of slowing down
gluconeogenesis. [19]

Stevia may benefit people at risk of certain cancers, but the evidence is very limited. Yasukawa K and his co-workers
isolated four steviol (ent-kaurene-type diterpenoid) glycosides, stevioside, rebaudiosides A and C, and dulcoside A) from
Stevia rebaudiana BERTONI and they found a strong inhibitory effect of these steviols on 12-O-tetradecanoylphorbol-13-
acetate (TPA)-induced inflammation in mice. [20]

Stevia may have benefits of anti-microbial activities, the scientific evidence is very limited. Amaro-Luis et al isolated
ombuoside from aerial parts of Stevia triflora and prepared derivatives of it- octa-acetylombuoside, ombuine and
retusine. They found these compounds were against a few types of gram positive bacteria. [21]

Rats received a single oral administration of either steviol or stevia mixture; a peak steviol plasma concentration
appeared 15 min after its oral administration. However, after oral administration of stevia mixture, the steviol
concentration in plasma increased steadily over 8 h, [22]

Stevia probably is safe without significant adverse or toxic effects [4,6,9]. Stevia accounts for about 40% of the sweetener
market in Japan and is widely used in South America.[5] However, I received piles of complaints from readers on
side effects.

[1] Leung AY, Foster S. Encyclopedia of Common Natural Ingredients Used in Foods, Drugs, and Cosmetics, 2d ed. New York: John Wiley & Sons, 1996, 478–80.
[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;19:771–4. [3]
White JR Jr, Kramer J, Campbell RK, Bernstein R. Oral use of a topical preparation containing an extract of Stevia rebaudiana and the chrysanthemum flower in
the management of hyperglycemia. Diabetes Care 1994;17:940.[4] Leung AY, Foster S. Encyclopedia of Common Natural Ingredients Used in Foods, Drugs, and
Cosmetics, 2d ed. New York: John Wiley & Sons, 1996, 478–80. [5] Blumenthal M. FDA rejects AHPA stevia petition. Whole Foods 1994:Apr;61–4. [6] Geuns
JM. Stevioside. Phytochemistry. 2003 Nov;64(5):913-21. [7] D'Agostino M, De Simone F, Pizza C, Aquino R. Sterols in Stevia rebaudiana Bertoni. Boll Soc Ital
Biol Sper. 1984 Dec 30;60(12):2237-40.[8] Melis MS Stevioside effect on renal function of normal and hypertensive rats. J Ethnopharmacol. 1992 Jun;36(3):213-7.
[9] Chan P et al A double-blind placebo-controlled study of the effectiveness and tolerability of oral stevioside in human hypertension. Br J Clin Pharmacol. 2000
Sep;50(3):215-20.[10] Chan P et al, The effect of stevioside on blood pressure and plasma catecholamines in spontaneously hypertensive rats. Life Sci. 1998;63
(19):1679-84. [11] Lee CN et al Inhibitory effect of stevioside on calcium influx to produce antihypertension. Planta Med. 2001 Dec;67(9):796-9].[12] Hsu YH et al,
Antihypertensive effect of stevioside in different strains of hypertensive rats. Zhonghua Yi Xue Za Zhi (Taipei). 2002 Jan;65(1):1-6. [13]Liu JC et al Mechanism of
the antihypertensive effect of stevioside in anesthetized dogs. Pharmacology. 2003 Jan;67(1):14-20.[14] Hsieh MH et al Efficacy and tolerability of oral stevioside
in patients with mild essential hypertension: a two-year, randomized, placebo-controlled study. Clin Ther. 2003 Nov;25(11):2797-808.[15] Curi R et al, Effect of
Stevia rebaudiana on glucose tolerance in normal adult humans. Braz J Med Biol Res. 1986;19(6):771-4.[16] Jeppesen PB et al, Stevioside acts directly on
pancreatic beta cells to secrete insulin: actions independent of cyclic adenosine monophosphate and adenosine triphosphate-sensitive K+-channel activity.
Metabolism. 2000 Feb;49(2):208-14.[17] Jeppesen PB et al, Stevioside induces antihyperglycaemic, insulinotropic and glucagonostatic effects in vivo: studies in
the diabetic Goto-Kakizaki (GK) rats. Phytomedicine. 2002 Jan;9(1):9-14. 18] Gregersen S, Jeppesen PB, Holst JJ, Hermansen K. Antihyperglycemic effects of
stevioside in type 2 diabetic subjects. Metabolism. 2004 Jan;53(1):73-6.[19] Chen TH et al Mechanism of the hypoglycemic effect of stevioside, a glycoside of
Stevia rebaudiana. Planta Med. 2005 Feb;71(2):108-13.[20] Yasukawa K  et al Inhibitory effect of stevioside on tumor promotion by 12-O-tetradecanoylphorbol-13-
acetate in two-stage carcinogenesis in mouse skin. Pharm Bull. 2002 Nov;25(11):1488-90.[21] Amaro-Luis et al Isolation, identification and antimicrobial activity
of ombuoside from Stevia triflora. Ann Pharm Fr. 1997;55(6):262-8[22] Koyama E et al. Absorption and metabolism of glycosidic sweeteners of stevia mixture and
their aglycone, steviol, in rats and humans. Food Chem Toxicol. 2003 Jun;41(6):875-83.
[23] Sekihashi K et al Genotoxicity studies of stevia extract and steviol by the comet assay, J Toxicol Sci. 2002 Dec;27 Suppl 1:1-8.[24] Melis MS. Effects of
chronic administration of Stevia rebaudiana on fertility in rats. J Ethnopharmacol. 1999 Nov 1;67(2):157-61.
STEVIA health benefits                    
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