STEVIA REPORT-HEALTH BENEFITS, WARNING, AND USES

STEVIA FACTS

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]

STEVIA HEALTH BENEFITS ON HIGH BLOOD
PRESSURE - RESEARCH STUDIES

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 HEALTH BENEFITS ON GLUCOSE
TOLERANCE
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]

DOES STEVIA HAVE ANTI-CANCER OR ANTI-TUMOR ACTIVITIES?
Stevia may have anti-cancer activities, 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]

DOES STEVIA HAVE ANTI-MICROBIAL ACTIVITIES? Stevia may have
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]

HOW DOES STEVIA ABSORBED AND METABOLISED?
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]

DOSAGE AND SIDE EFFECTS OF STEVIA
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]

Note: With regard to stevia use in foods, stevia is not an approved food
additive nor affirmed as GRAS in the United States. Available
toxicological information on stevia is inadequate to demonstrate its
safety as a food additive or to affirm its status as GRAS. However, with
regard to its use in dietary supplements, dietary ingredients, including
stevia, are not subject to food additive regulations. [AUTOMATIC
DETENTION OF STEVIA LEAVES, EXTRACT OF STEVIA LEAVES, AND
FOOD CONTAINING STEVIA, IA 45-06, FDA DOCUMENT]

HOWEVER OVERDOSE OF STEVIA IS SERIOUS, MAY LEAD TO
HEADACHE AND MORE: SIDE EFFECTS IN DETAILS

THIS ARTICLE IS FOR YOUR REFERENCE ONLY. YOU SHOULD CONSULT YOUR DOCTOR
FOR ANY QUESTIONS. ALL RIGHTS RESERVED 2006 ZHION

References
[1] Leung AY, Foster S. Encyclopedia of Common Natural Ingredients Used in Foods, Drugs, and
Cosmetics, 2d ed. New York: John Wiley & Sons, 1996, 478Â–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;19:771Â–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, 478Â–80. [5] Blumenthal M. FDA rejects AHPA stevia petition.
Whole Foods 1994:Apr;61Â–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
and side effects
Zhion@zhion.com updated on November, 2008