Content uploaded by Virendra V. Panpatil
Author content
All content in this area was uploaded by Virendra V. Panpatil on Feb 24, 2023
Content may be subject to copyright.
467
J Food Sci Technol, 2008, 45(6), 467–473
Stevia (Stevia rebaudiana) is a small
shrub native to subtropical and tropical
South America and Central America
(North to Mexico, Paraguay and Brazil).
Native Indians of the Guarani Tribe ap-
pear to have used the leaves of this herb
as a sweetener since pre-Columbian times.
It is also called as sweet leaf or sugar leaf
and is a genus of about 150 species of
herbs and shrubs. It grows well in the
sandy soil of elevated land and may grow
to a height of 80 cm when it is fully
mature. Stevia does produce seeds, but
only a small percentage of them germi-
nate. Planting cloned stevia is a much
more effective method of reproduction. In
1887, a South American natural scientist
named Antonio Bertoni first discovered
it. First Bertoni nominated this plant as
Eupatorium rebaudianum, but later shifted
it to the genus Stevia. Bertoni named the
“new” variety of the stevia genus in honor
of a Paraguayan chemist named Rebaudi,
who became the first to extract the plant’s
sweet constituent.
Different glycosides extracted from
the stevia (Rebaudi 1900, Korbert 1915,
Pomaret and Lavieille 1931) were named
steviosides, rebaudiosides and dulcoside.
Besides the intensely sweet glycosides,
stevia leaf contains proteins, fiber, Fe, P,
Ca, K, Na, Mg, Zn, rutin (a flavonoid),
vitamin A, vitamin C and oil, which con-
tains 53 other constituents. Processed
forms of stevia are 250-300 times sweeter
than sugar. Stevia leaf is about 5 cm long
and 2 cm wide and leaves arrangement is
crosswise, facing each other. Environmen-
tal factors like soil, irrigation methods,
sunlight, air purity, cleanliness, farming
Assessment of stevia (Stevia rebaudiana)-natural sweetener: A review
Virendra V Panpatil*, Kalpagam Polasa
Food and Drug Toxicology Research Centre, National Institute of Nutrition, Hyderabad-500 604, India
*E-mail:virendra.nin@gmail.com
Stevia (Stevia rebaudiana) is the sweetener of the future. Steviosides and rebaudiosides are the sweetest form of
stevia. Stevioside is commonly used as a non-caloric sugar substitute in Japan, Korea, Brazil, China and Paraguay. Pure
stevia extract does not affect blood glucose level and may be used freely by diabetics. Stevia also has important role
in medical research for treating diabetes, obesity, high blood pressure, tooth cavity and skin problems. The safety of
stevia extracts has been confirmed by various toxicity, mutagenicity and other studies. Although more recent studies
appear to establish the safety of stevia, government agencies have expressed concerns over toxicity, citing lack of sufficient
conclusive research.
Keywords: Stevia rebaudiana, Stevioside, Steviol, Toxicity, Sweetener
practices, processing and storage affect
stevia quality. Quality of stevia should be
compared on the basis of aroma, taste,
appearance and sweetness. In a 62-year-
old sample from stevia leaf herbarium,
the intense sweetness of stevia was con-
served, indicating the stability of stevioside
to dr ying, preserv ation and st orage
(Soejarto et al 1982, Hanson and De
Oliveira 1993).
Stevioside
Stevia leaves contain a complex
mixture of sweet diterpene glycosides,
includi ng stev ios ide , ste violbioside,
rebaudiosides (A, B, C, D, E, F) and
dulcoside A (Kennelly 2002, Starrat et al
2002). Stevioside is isolated and purified
from Stevia rebaudiana Bertoni leaves
after multiple and selective extractions
followed by recrystallisation, resulting in
a stevios ide puri ty >95% a nd with
rebaudioside A as the main impurity (≤2).
Refined steviosides and rebaudiosides are
the sweetest forms of stevia. Stevioside
constitutes 5-15% of the dried leaves of
stevia (Lima Filho and Malavolta 1997).
The biochemical pathway for the forma-
tion of steviol is partly known (Kim et al
1996) and a simple and efficient method
for the extraction of steviol glycosides
has been described (Liu et al 1997). The
chem ica l stru ctu re of steviosid es
(Nanayakkara et al 1987, Suttajit et al
1993), rebaudioside A, steviol (metabo-
lite of stevioside) is shown in Fig. 1. The
EC50 of stevioside is 650 mg/kg, steviol
is more active with EC50 of 150 mg/kg.
Steviol loses its deterrent activity after
acetylation or glycosylation of the C-13
tertiary hydroxy group or methylation of
the C-19 carboxylic acid substituent, but
the activity of steviol is not greatly af-
fected by modification of either the C-16
exomethylene group or its stereochemis-
try (Nanayakkara et al 1987).
Benefits of stevia (not approved or
confirmed by FDA).
No calories, will not affect blood
sugar levels like common sugar, 100%
natural, 250 to 300 times sweeter than
sugar, heat stable up to 200°C, non-fer-
mentable, flavour enhancer, prevents cavi-
ties, recommended for diabetics, non-toxic,
leaves can be used in their natural state,
Fig. 1. Structure of stevioside, rebaudioside A and steviol
468
huge sweetening power and only small
quantities are need to be used, leaves as
well as the pure stevioside extract can be
cooked, no bitterness and non-addictive
sweetener for children.
Comparison between stevia and other
artificial sweeteners
A study conducted by the Depart-
ment of Food and Nutrition, FCF-UNESP
in Araraquara, Brazil, compared the rela-
tive sweetness of stevia to that of aspar-
tame, a cyclamate/saccharin combination
and 10% sucrose concentration. The re-
sults were interesting. An equivalent dose
of stevia, aspartame, cyclamate/saccharin
combination and 10% sucrose concentra-
tion all had practically the same potency
(Cardello et al 1999). Stevia has lower
calorie and glycemic index compared to
common sugar. Stevia has good source of
protein, ash and crude fiber which are
essential for good health (Savita et al
2004).
Health concerns
Human body does not metabolize the
raw or processed form of sweet glyco-
sides. They are excreted through the nor-
mal elimination channels. Human body
does not obtain any calories from stevia.
If stevia extracts are in their pure unadul-
terated form they do not adversely affect
blood glucose levels and may be used
freely by diabetics.
Diabetes: Stevia leaves have been
used as herbal teas by diabetic patients in
Asian countries. No side effects have been
observed in these patients after many years
of continued consumption (Suttajit et al
1993). Furthermore, studies have shown
that stevia extract can actually improve
blood sugar levels (Curi et al 1986).
Stevioside helps in insulin secretion; it
acts directly on pancreatic beta cells to
secret insulin (Jeppesen et al 2000).
Stevioside had no effect on gluconeogen-
esis or oxygen uptake in isolated Wistar
rat renal cortical tubules at concentrations
up to 3 mmol/l, equivalent to 2.4 mg/ml.
Lack of activity was due to the inability
of stevioside to penetrate the cell mem-
brane (Yamamoto et al 1985).
Blood pressure: Three days of oral
stevioside administration (750 mg/day)
affected neither the systolic or diastolic
blood pressure nor the fasting plasma
glucose and insulin concentrations of
healthy volunteers (Geuns et al 2007).
One-time high dose of stevioside to rats
resulted in reduction of blood pressure as
well as an increased elimination of Na
(Melis and Sainati 1991). A slight di-
uretic effect also occurred. The effect was
additive when stevia was combined with
verapamil (a medicine used to lower blood
pressure in humans who have high blood
pressure).
Melis (1995) administered extracts
of stevia to rats for 20, 40, and 60 days.
After 20 days, there were no changes in
the stevia treated rats compared to the
control group. But, after 40 or 60 days of
administering the extract, there was a
lowering of blood pressure; a diuretic
effect was noted along with loss of so-
dium. The amount of blood going to the
kidneys increased. Similar results were
observed in human study. When normal
human volunteers between the ages of 20
- 40 years were given tea prepared with
stevia leaves, a lowering of blood pres-
sure occurred (Boeckh 1981).
Teeth without cavities: There are
several bacteria present in our oral cavity,
particularly Streptococci mutans, which
ferment various sugars to produce acids.
These in turn damage the tooth enamel
and form pockets or cavities. Stevioside
and rebaudioside A, the two primary sweet
constituents of the stevia plant were tested
in a group of 60 rat pups (Das et al 1992).
Rats were divided in 4 groups that is one
control and 3 experimental (Stevioside,
rebaudioside A and sugar) groups. There
was no change in food and water intake
and weight gain between the experimental
and control group. However, the sugar
fed group had significantly more cavities
than the rest of the groups. It was con-
cluded that neither steviosid e nor
rebaudioside A is cariogenic (cavity caus-
ing) under the experimental conditions. It
shows that the chemicals within the stevia
plant that impart sweetness are not fer-
mentable, and thus does not cause tooth
cavities.
Biological effects
Absorption, distribution and excre-
tion: After oral application of radio-la-
beled stevioside, 1.5% of the radioactiv-
ity was excreted in the urine of intact rats,
whereas in rats with a ligated bile duct
96% of the radio-activity was excreted in
the urine. This indicates enterohepatic
circulation of stevioside and/or its me-
tabolites with an elimination half-life of
24 h. Aft er oral a dmi nis tra tio n of
stevioside to the rat, a major part seems
to be degraded by the gut flora to steviol
(Nakayama et al 1986). In another study,
labeled 131I-stevioside was injected intra-
venously to male Wistar rats. Plasma level
of radiolabel decreased fast. It shows rapid
distribution in the body. The highest con-
centrations of radiolabel were found at 10
and 120 min after injection in the liver
(45 and 5% of the injected dose, respec-
tively) and the small intestine (18 and
66%). At 120 min after injection, the
radiolabel eliminated in the bile repre-
sented 52% of the original dose. After 24
h of injection, the radiolabel eliminated
35% of the original dose in both faeces
and urine (Cardoso et al 1996). It was
concluded that this study was of limited
value since introduction of a large 131I
atom into stevioside might significantly
affect its absorption, distribution, metabo-
lism, and excretion in bile or urine.
The renal excretion of stevioside and
its effect on the renal excretion of several
other substances were studied in groups
of 10 male Wistar rats (Melis 1992).
Stevioside was administered intravenously
at doses of 4, 8, 12, or 16 mg/kg body
weight (bw/h) for 30 min. It was observed
that there was no major change in inulin
clearance, but there was a considerable
increase in para-aminohippuric acid clear-
ance, fractional sodium excretion, urinary
flow as percent of glomerular filtration
rate, and glucose clearance when com-
pared with controls at doses greater than
4 mg/kg bw/h. Stevioside clearance was
greater than inulin clearance and smaller
than para-amino-hippuric acid clearance
at all doses tested. It was concluded that
stevioside was secreted by the renal tubu-
lar epithelium and induces diuresis and
natriuresis and a decrease in renal tubular
reabsorption of glucose.
Of the administered labeledstevioside
orally, 1.5% of the radioactivity was
excreted in the urine of intact rats, whereas
in rats with a ligated bile duct 96% of the
radio-activity was excreted in the urine.
This indicates enterohepatic circulation of
stevioside and/or its metabolites with an
elimination half-life of 24 h. After admin-
J Food Sci Technol, 2008, 45(6), 467–473
469
istration of stevioside to the rat, a major
part was degraded by the gut flora to
steviol. In vitro studies using the rat in-
testinal microflora have shown that the
degradation, within 2 days of stevioside
and rebaudioside A to steviol are approxi-
mate ly 100 a nd 6 5%, res pec tiv ely .
Stevioside was not absorbed, but steviol
was readily absorbed and later excreted in
the bile as conjugates, which subsequently
were excreted in the faeces (Wingard et
al 1980, Nakayama et al 1986). Degrada-
tion of stevioside was recently shown to
occur by various digestive enzymes from
the gastrointestinal tract of different ani-
mal species. The microflora of the human
faeces metabolized stevioside to both
steviol and steviol-epoxide. Thus, steviol
and its epoxide may be formed and sub-
sequently absorbed (Koyama et al 2003).
Effects on enzymes: Stevioside given
to female RCR/Ha mice did not stimulate
activity of glutathione S-transferase in liver
or intestinal mucosa (Pezzuto et al 1986).
Stevioside (0.8 mg/ml) inhibited oxida-
tive phosphorylation and the activity of
ATPase by 50%, succinate oxidase by 8%
inhibition, and succinate dehydrogenase
by 10% and no inhibition was observed
in NADH-oxidase or L-glutamate dehy-
drogenase activity. The authors stated that
stevioside acts as a weak uncoupler of
oxidative phosphorylation (Kelmer-Bracht
et al 1985). The stevioside administered
to hamster at 0.8 and 4 mg/ml, and intes-
tinal glucose absorption was examined in
hamster jejunum. Glucose absorption was
not inhibited (Toskulkao et al 1995a, b);
12 µg/ml of stevioside did not signifi-
cantly alter the arginine-induced secretion
of insulin or glucagon in the pancreas of
male Wistar rats (Usami et al 1980).
Toxicology
Acute toxicity: Acute toxicity studies
of the stevioside are summarized in Table
1. In these studies, no lethality was seen
within 14 days after oral administration,
and no clinical signs of toxicity or mor-
phological or histopathological changes
were found.
After intravenous administration of
stevioside to pentobarbital-anaesthetized
dogs at a dose of 32.5 µmol/l/kg bw
(equivalent to 26 µg/kg bw), no signifi-
cant changes were seen in any parameters
of whole blood, plasma, or renal function
and there was no significant alteration of
the renal ultra structure. It was concluded
that stevioside is totally devoid of acute
extra renal effects (such as hypoxemia,
which could contribute to nephrotoxicity)
and direct renal effects during the 6 h
period following intravenous administra-
tion (Krejci and Koechel 1992). After
intr aperiton eal injec tio n of purified
stevioside to mice and rats at a dose of
2.99 g/kg bw, no toxic effect was de-
tected. The high dosages needed for the
experiments did not permit to reach the
real LD50 (Mitsuhashi 1976).
Subacute toxicity: A subacute toxic-
ity study was carried out on rats using an
aqueous extract of stevia containing about
50% w/w stevioside. Rats were divided
into control, 0.25 and 0.5 g of stevioside.
Animals were fed the experimental diets
for 56 days. There were no abnormalities
in stevia fed groups. But researchers could
find a significant decrease in serum lactic
dehy dro gen ase leve ls. (Asaki a nd
Yokoyama 1975).
Subchronic toxicity: A subchronic
oral toxicity study of stevioside was car-
ried out in F344 rats at dose levels of 0,
0.31, 0.62, 1.25, 2.5 and 5% in diet. The
rats were randomly distributed into 6
groups, each consisting of 10 males and
10 females. Between the control and
treated groups, there were no differences
in body weight gain during the adminis-
tration period and in food consumption in
the later period of the study. During bio-
chemical and histopathological investiga-
tion, researchers found increased level of
LDH and single cell necrosis in the liver
in all male treated groups. But these were
not considered as specific changes, be-
cause of the lack of any clear dose re-
sponse, the relatively low severity and the
limitation to males. Other parameters that
were found to demonstrate significant
differences on hematological and bio-
chemical investigations were of minor
toxicological significance. From these
results, a concentration of 5% in diet was
concluded to be a suitable maximum tol-
erable dose of stevioside for 2 years
carcinogenicity study in rats (Aze et al
1991).
Long term toxicity and carcinoge-
nicity: Stevia extracts were tested for 2
years, on 500 male and female F344 rats.
Rats received stevia extract at 1% of their
feed. It was concluded that no significant
dose-related changes were found in the
growth, general appearance, hematologi-
cal and blood biochemical findings, organ
weights, and macroscopic or microscopic
observations. The results obtained are
supportive of the safety of stevia extracts,
stevioside and rebaudioside A (Yamada
et al 1985).
A carcinogenicity study was per-
formed in F344 rats, using a stevioside
extract (95.6% purity). The doses were
155, 310, 625, 1250 and 2500 mg/kg bw/
day, each group consisted of 50 males
and 50 females. It was concluded that
stevioside was not carcinogenic in F344
rats under these experimental conditions.
However, almost all male rats including
controls developed interstitial cell tumors
in the testis. It was suggested that a chronic
oral toxicity and carcinogenicity study
should be performed in another rat spe-
cies than F344 (Xili et al 1992).
So researchers performed a 2 years
study in Wistar rats, using a stevioside
powder of 85% purity. Stevioside was
given in the diet at 100, 300 and 600 mg/
kg bw/day. Body weight, food consump-
tion, general appearance, and mortality
were similar in treated and control groups.
The mean life span of treated rats was not
significantly different from that of the
controls. No changes were observed in
hematological, urinary or clinical bio-
chemical. The incidence and severity of
Table 1. Acute toxicity of stevioside given orally to rodents
Species Sex LD50, g/kg bw Purity, % Reference
Mouse M and F >15 96 Toskulkao et al (1997)
Mouse M >2 96 Medon et al (1982)
Rat M and F >15 96 Toskulkao et al (1997)
Hamster M and F >15 96 Toskulkao et al (1997)
Mouse M and F >17 20 Asaki and Yokoyama (1975)
Mouse M and F >15 93.5 Asaki and Yokoyama (1975)
J Food Sci Technol, 2008, 45(6), 467–473
470
non-neoplastic and neoplastic changes
were unrelated to the concentration of
stevioside in the diet. The NOEL was
1.2%, equivalent to 600 mg/kg bw/day.
Xili (1992) suggested that the acceptable
daily intake of stevioside for humans was
7.9 mg/kg bw/day.
Stevioside (purity, 95.6%) was added
to diet at 0, 2.5 and 5% levels. Study was
conducted in 50 male and 50 female
Fischer 344/DuCrj rats for 104 weeks. All
surviving rats were sacrificed at 108th
week. When the organs and tissues of the
rats were microscopically examined, there
was almost no difference between treated
and control group. Also there was de-
creased incidence of breast tumors in
treated females, and the males showed a
lesser incidence of kidney damage. It was
concluded that stevioside was not carci-
nogenic in rats under the experimental
conditions. In histopathological examina-
tion, there was no significantly altered
development of neoplastic or non-neo-
plastic changes, except for a decreased
incidence of mammary adenomas in fe-
males and a reduced severity of chronic
nephropathy in males. It was concluded
that stevioside was not carcinogenic un-
der the experimental conditions (Toyoda
et al 1995, 1997).
The effect of stevioside on uri-
nary bladder carcinogenesis was carried
out in F344 male rats; 0.01% of the ni-
trosamine was administered through drink-
ing-water for 4 weeks and then 5%
stevioside was given through diet for 32
weeks. All surviving rats were sacrificed
after 36 weeks and examined histologi-
cally. Treatment with 5% stevioside did
not affect the incidence or extent of pap-
illary or nodular hyperplasia in nitro-
samine-treated rats. No preneoplastic or
neoplastic lesions of the urinary bladder
were obser ved in rat s tr eated wit h
stevioside only. It was concluded that
stevioside does not promote bladder car-
cinogenesis (Hagiwara et al 1984, Ito et
al 1984).
Genotoxicity: In a genotoxicity study
Wistar rats were treated with 4 mg/ml
stevioside for 45 days (7 weeks). DNA
damage was analyzed by Comet assay
every week, and it was found that there
was no significant difference between
control and treated groups until 4th week.
But from 5th week significant increase in
DNA damage in control as well treated
group was seen. It was suggested that this
may be due to stress or statistical differ-
ences between both the groups. After 45
days, animals were sacrificed and liver,
brain and spleen were collected for analy-
sis. There was significant increase in DNA
damage in treated groups. In addition,
more DNA damage was observed in
spleen. It was suggested for additional
studies for a better understanding of the
molecular stevioside action in metabolism
(Nunes et al 2007). An in vitro and in
vivo study of stevia extract showed nega-
tive response, stevia extract and steviol
did not show DNA-damaging activity in
cultured cells and mouse organs (Sekihashi
et al 2002). Genotoxicity studies of the
stevioside by reverse mutation, forward
mutation, gene mutation and chromosomal
aberration are summarized in Table 2,
which shows that the results were found
to be negative.
Reproductive toxicity
Hamster: A study conducted on ham-
ster to see the effect of daily ingestion of
stevioside and its effects on two subse-
quent generations showed no significant
difference in the average growth of the
first generation of hamsters in the groups
receiving 500, 1000 and 2500 mg/kg bw
of stevioside. Even the third generation of
hamsters, at 120 days of age, showed no
significant differences in body weight of
all experimental groups. In all three gen-
erations mating performance was equal to
the controls, irrespective of the dose of
stevioside they received. Stevioside at 2.5
g/kg bw affected neither the growth nor
reproduction in hamsters (Yodyingyuad
and Bunyawong 1991).
Rat: Group of 11 male Wistar rats
were given stevioside (purity, 96%) in the
diet at 0, 150, 750, and 3000 mg/kg bw/
day for 60 days before and during mating,
and groups of 11 female Wistar rats re-
ceived the same diet for 14 days before
mating and for 7 days during gestation. At
high dose slight decrease in body-weight
gain was observed. There was no treat-
ment-related effect on mating performance
or fertility, and no deformities were seen
in the fetuses. Stevioside had no adverse
effect on fertility or on the development
of fetuses (Mori et al 1981). They also
noted a slight but not statistically signifi-
cant increase in the number of dead or
resorbed fetuses at the highest dose. But
in another study 5 g dry stevia in 100 ml
water was given orally to inbred, adult
female rats for 18 days. Females were
mated with untreated male rats during the
last 6 days. Fertility was reduced to 21%
of control rats and remained reduced
(47%) even after 50-60 days recovery
period (Mazzei-Planas and Kuc 1968).
Table 2. Genotoxicity of stevioside
Assay Test object Concentration Results Reference
Reverse mutation S. typhimurium TA98, TA100 50 mg/plate1Negative Klongpanichpak et al (1997)
Reverse mutation S. typhimurium TA98, TA100 50 mg/plate1Negative2Suttajit et al (1993)
Reverse mutation S. typhimurium TA97, TA98, TA100, 5 mg/plate3Negative Matsui et al (1996)
Forward mutation S. typhimurium TM677 10 mg/plate1Negative Matsui et al (1996)
Forward mutation S. typhimurium TM677 10 mg/plate1Negative Pezzuto et al (1985)
Forward mutation S. typhimurium TM677 Not specified1Negative Medon et al (1982)
Gene mutation B. subtilis H17 rec+, M45 rec-10 mg/disc1Negative Matsui et al (1996)
Chromosomal aberration Chinese hamster lung fibroblasts 8 mg/ml3; 12 mg/ml4Negative Matsui et al (1996)
Chromosomal aberration Human lymphocytes 10 mg/ml Negative Suttajit et al (1993)
Chromosomal aberration Chinese hamster lung fibroblasts 12 mg/ml3Negative Ishidate et al (1984)
1With and without metabolic activation, 2A positive response towards TA98 was seen without metabolic activation at 50 mg/ml, but not at
lower concentrations up to 20 mg/ml, 3Without metabolic activation, 4With metabolic activation
J Food Sci Technol, 2008, 45(6), 467–473
471
Teratogenicity study: Teratogenicity
of stevioside (purity, 95.6%) was exam-
ined in rats. Stevioside dissolved in dis-
tilled water was given to pregnant Wistar
rats by gavage once a day from days 6 to
15 of gestation at doses of 0, 250, 500
and 1000 mg/kg/day. The rats were sac-
rificed on 20th day of pregnancy and their
fetuses were examined for malformation.
Stevioside caused no increased incidences
of fetal malformation, and no toxic signs
in the pregnant rats and the fetuses. It was
concluded that stevioside has no teratoge-
nicity in rats when given by gavage
(Takanaka et al 1991, Usami et al 1995).
Special studies
a. Detection test made by Japan Food
Sanitation Corporation in 1992: Ar-
senic, lead, cadmium, tin, or patho-
genic bacteria were not detected.
b. Patch test made by the Association of
Japan Hair Science in 1990: All nega-
tive. The fin chambers with stevia
extract liquid applied were pasted tight
on the elbow skin of 42 examinees for
48 h.
c. Live bacteria test made by Kitazato
University Hygiene Science Center in
1991: All negative
d. Detection test on prohibited drugs
made by Laboratory of Japan Racing
Chemistry Foundation in 1991: All
negative
Government actions
Food and Drug Administration of the
United States labeled stevia as an “unsafe
food additive” and restricted its import.
The stated reason of FDA was “toxico-
logical information on stevia is inadequate
to demonstrate its safety.” The Scientific
Committee on Food for the European
Commission concluded that “there are no
satisfactory data to support the safe use of
stevia leaves.” The Committee also re-
stat ed “it s earlier opinio n that th e
stevioside is not acceptable as a sweet-
ener on the presently available data.” The
Joint FAO/WHO Expert Committee on
Food Additives ( JEC FA) rev iew ed
stevioside in 1998, but could not quantify
an Acceptable Daily Intake (ADI) be-
cause of inadequate data on the compo-
sition and safety of stevioside. The 63rd
meeting of the Joint FAO/WHO Expert
Committee (2005) on Food Additives
(JECFA) reviewed stevioside. The Com-
mittee concluded that stevioside and
rebaudioside A are not genotoxic in in
vitro or in vivo and genotoxicity of steviol
and some of its oxidative derivatives in
vitro is not expressed in vivo. The NOEL
for stevioside was 970 mg/kg bw/day in
a long-term study evaluated by the com-
mittee at its 51st meeting. The committee
noted that stevioside has shown some
evidence of pharmacological effects in
patients with hypertension or with type-2
diabetes at doses of 12.5–25 mg/kg bw/
day [equivalent to 5–10 mg/kg bw/day
expressed as steviol (a metabolite of
stevioside)].
The evidence available at present is
inadequate to assess whether these phar-
macological effects would also occur at
lower levels of dietary exposure, which
could lead to adverse effects in some
individuals (e.g. those with hypotension
or diabetes). The Committee therefore
decided to allocate a temporary ADI,
pending submission of further data on the
pharmacological effects of steviol glyco-
sides in humans. A temporary ADI of 0–
2 mg/kg bw was established for steviol
glycosides, expressed as steviol, on the
basis of the NOEL for stevioside of 970
mg/kg bw/day (or 383 mg/kg bw/day,
expressed as steviol). The committee noted
that this temporary ADI only applies to
products complying with the specifica-
tions. The committee required additional
information to be provided by 2007, on
the pharmacological effects of steviol
glycosides in humans. These studies should
involve repeated exposure to dietary and
therapeutic doses, in normotensive and
hypotensive individuals and in insulin-
dependent and insulin-independent dia-
betics. A toxicological monograph was
prepared, incorporating summaries of the
key toxicological data on the evaluation
of stevioside conducted by the committee
at its 51st meeting. New tentative specifi-
cations were prepared, accompanied by a
chemical and technical assessment. In
order to be able to remove the tentative
designation from the specifications, fur-
ther information for commercially avail-
able products was required by 2007 (WHO
2005).
Conclusion
People are using stevia from last 1500
years in Paraguay and 30 years in Japan,
but so far no complaint has been reported.
It is safe for human consumption and has
several benefits. Stevioside is used as
non-caloric substitute. Persons having
diabetes, obesity, high blood pressure,
tooth cavity and skin problems can use
stevia. Stevioside has very low acute tox-
icity. Ac ute toxi city stu dies of t he
stevioside showed no lethality within 14
days and no clinical signs of toxicity or
morphol ogi cal or hist opa tho log ica l
changes were found. In a subacute toxic-
ity study on rats, no abnormalities were
found, except a significant decrease in
serum lactic dehydrogenase levels.
In a subchronic oral toxicity study of
stevioside in F344 rats, increased level of
LDH and single cell necrosis in the liver
in all male treated groups were noticed.
Stevioside is not carcinogenic in rats under
the experimental conditions. In vitro and
in vivo genotoxicity studies of stevia
extract showed negative responses, stevia
extract and steviol do not have DNA-
damaging activity in cultured cells and
mouse organs. A reproductive toxicity
study conducted on hamster showed no
significant difference in the average growth
of the first generation and third genera-
tion of hamsters. In all three generations
mating performance was equal to the
controls. But in rat, slight decreased body-
weight gain was observed in high dose.
There was no effect on mating perfor-
mance or fertility, and no deformities were
seen in the fetuses. But in females fertility
was reduced. Teratogenicity of stevioside
in rats, showed no increased incidences of
fetal malformation, and no toxic signs in
the pregnant rats and the fetuses.
Although not all of stevia’s potential
side effects may have been identified, its
main known side effect is an itchy rash
that individuals who are allergic get from
handling the plants. Stevia should be
avoided by pregnant and breast-feeding
women due to a lack of information about
its possible effects on developing babies
and infants. Individuals with kidney con-
ditions should also avoid taking stevia
because some laboratory animals have
suffered kidney damage when they were
given high doses.
The government agencies like
USFDA and WHO are not satisfied with
the submitted documentation and have
J Food Sci Technol, 2008, 45(6), 467–473
472
concern about possible toxicity and hence
still it is not acceptable as a sweetener
based on the presently available data.
References
Asaki H, Yokoyama Y 1975. Dried-leaf ex-
tr ac ts of stev ia t oxi col ogica l tes ts .
Shokukin Kogyo 18:34-43
Aze Y, Toyoda K, Imaida K, Hayashi S,
Imazawa T, Hayashi Y, Takahashi M 1991.
Subchronic oral toxicity study of stevioside
in F344 rats. Bull Nat Inst Hyg Sci 109:48-
54
Boeckh EM 1981. Stevia rebaudiana Bertoni:
Cardio-circulatory effects of total water
ex trac t in norm a l pers o ns and of
stevioside in rats and frogs. First Brazil-
ian Seminar on Stevia rebaudiana. Inst
Technol Aliment, Campinas, Brazil, p
11.1-11.2
Cardello HM, Da Silva MA, Damasio MH
1999. Measurement of relative sweetness
of stevia extract, aspartame and cycla-
mate/saccharin blend as compared to su-
crose at different concentrations. Plant
Food Hum Nutr 54:119-130
Cardoso VN, Barbosa MF, Muramoto E,
Mesquita CH, Almeida MA 1996. Phar-
macokinetic studies of 131I-stevioside and
its metabolites. Nucl Med Biol 23:97-100
Curi R, Alvarez M, Bazotte RB, Botion LM,
Godoy JL, Bracht A 1986. Effect of Stevia
rebaudiana on glucose tolerance in nor-
mal adult humans. Brazil J Med Biol Res
19:771-774
Das S, Das AK, Murphy RA, Punwani IC,
Nasution MP, Kinghorn AD 1992. Evalu-
ation of the cariogenic potential of the
intense natural sweeteners stevioside and
rebaudioside A. Caries Res 26:363-366
Geuns JMC, Buyse J, Vankeirsbilck A, Temme
EH 2007. Metabolism of stevioside by
healthy subjects. Exp Biol Med 232:164-
173
Hagiwara A, Fukushima S, Kitaori M, Shibata
M, Ito N 1984. Effects of three sweeten-
ers on rat urinary bladder carcinogenesis
initiated by N-butyl-N-(4-hydroxybutyl)
nitrosamine. Gann 75:763-768
Hanson JR, De Oliveira BH 1993. Stevioside
and related sweet diterpenoid glycosides.
Nat Prod Rep 10:301-309
Ishidate M, Sofuni T, Yoshikawa K, Hayashi
M, Nohmi T, Sawada M, Matsuoka A
1984. Primary mutagenicity screening of
food additives currently used in Japan.
Food Chem Toxicol 22:623-636
Ito N, Fukushima S, Shirai T, Hagiwara A,
Imaida K 1984. Drugs, food additives and
natural products as promoters in rat uri-
nary bladder carcinogenesis. In: Models,
mechanisms and etiology of tumour pro-
motion. Börzsönyi M, Day NE, Lapis K,
Yamasaki H (eds), IARC Scientific Pub-
lications Nr 56, International Agency for
Research on Cancer, Lyon, p 399-407
Jepp esen PB, Gregersen S, Poulsen CR,
Hermansen K 2000. Stevioside acts di-
rectly on pancreatic beta cells to secrete
insulin: actions independent of cyclic
adenosine monophosphate and adenosine
triphosphate-sensitive K+-channel activity.
Metabolism 49:208–214
Kelmer-Bracht AM, Alvarez M, Bracht A
1985. Effects of Stevia rebaudiana natu-
ral products on rat liver mitochondria.
Biochem Pharmacol 34:873-882
Kennelly EJ 2002. Sweet and non-sweet con-
stituents of Stevia rebaudiana (Bertoni)
Bertoni. In: Stevia, the genus Stevia.
Kinghorn AD (ed)., Medicinal and Aro-
matic Plants-Industrial Profiles. Taylor and
Francis, London. 19:68–85
Kim KK, Sawa Y, Shibata H 1996. Hy-
dro xy lation of ent-k au renoic acid to
steviol in Stevia rebaudiana Bertoni.
Purification and partial characterization
of the enzyme. Arch Biochem Biophys
332:223-230
Klongpanichpak S, Toskulkao C, Temcharoen
P, Apibal S, Glinsukon T 1997. Lack of
mutagenicity of stevioside and steviol in
Salmonella typhimurium TA 98 a nd
TA100. J Med Assoc Thailand 80:121–
128
Korbert R 1915. Ober Zwei Subschmeekend
Dorgen. Ber d Deutsch Pharm Ges 28:420-
443
Koyama E, Kitazawa K, Ohori Y, Izawa O,
Kakegawa K, Fujino A, Ui M 2003. In
vitro metabolism of the glycosidic sweet-
eners, stevia mixture and enzymatically
modified stevia in human intestinal mi-
croflora. Food Chem Toxicol 41:359–
374
Krejci ME, Koechel DA 1992. Acute effects
of carboxyatractyloside and stevioside,
inhibitors of mitochondrial ADP/ATP
translocation, on renal function and ultra-
structure in pentobarbital-anesthetized
dogs. Toxicology 72:299-313
Lima Filho OF de , Malavolta E 1997. Sinto
mas e desordens nutricionais em Estevia
Stevia rebaudiana (Bert.) Bertoni. Sci
Agric 54:53-61
Liu J, Ong CP, Li SFY 1997. Subcritical fluid
extraction of stevia sweeteners from Stevia
rebaudiana. J Chromatogr Sci 35:446-
450
Matsui M, Matsui K, Kawasaki Y, Oda Y,
Noguchi T, Kitagawa Y, Sawada M,
Hay ashi M, Noh mi T, Yoshi hi ra K,
Ishidate M, Sofuni T 1996. Evaluation of
the genotoxicity of stevioside and steviol
using six in vitro and one in vivo
mutagenicity assays. Mutagenesis 11:573-
579
Mazzei-Planas G, Kuc J 1968. Contraceptive
properties of Stevia rebaudiana. Science
162:1007
Medon PJ, Pezzuto JM, Hovanec-Brown JM,
Nanayakkara NP, Soejarto DD, Kamath
SK, Kinghorn AD 1982. Safety assess-
ment of some Stevia rebaudiana sweet
principles. Fed Proc 41:1568-1582
Melis MS 1992. Renal excretion of stevioside
in rats. J Nat Prod 55:688-690
Melis MS 1995. Chronic administration of
aqueous extract of Stevia rebaudiana in
rats: Renal effects. J Ethnopharmacol
47:129-134
Melis MS, Sainati AR 1991. Effect of cal-
cium and verapamil on renal function of
rats during treatment with stevioside. J
Ethnopharmacol 33:257–262
Mitsuhashi H 1976. Safety of stevioside. In:
Report on safety of stevia, Tama Bio-
chemical Co. Ltd, Tokyo. p 1-20
Mori N, Sakanoue M, Takeuchi M, Shimpo
K, Tanabe T 1981. Effect of stevioside on
fertility in rats. J Food Hyg Soc Japan
22:409-414
Nakayama K, Kasahara D, Yamamoto F 1986.
Absorption, distribution, metabolism and
excretion of stevioside in rats. J Food Hyg
Soc Japan 27:1-8
Nanayakkara NP, Klocke JA, Compadre CM,
Hussain RA, Pezzuto JM, Kinghorn AD
1987. Characterization and feeding deter-
rent effects on the aphid, Schizaphis
graminum, of some derivatives of the sweet
compounds, stevioside and rebaudioside
A. J Nat Prod 50:434-441
Nunes APM, Ferreira-Machado SC, Nunes
RM, Dantas FJS, De Mattos JCP, Caldeira-
de-Arujo A 2007. Analysis of genotoxic
potentiality of stevioside by Comet assay.
Food Chem Toxicol 45:662-666
Pezzuto JM, Compadre CM, Swanson SM,
Nanaya kkara D, K inghorn AD 1985.
Metabolically activated steviol, the agly-
cone of stevioside, is mutagenic. Proc
Natl Acad Sci USA p 2478-2482
Pezzuto JM, Nanayakkara NP, Compadre CM,
Swanson SM, Kinghorn AD, Guenthner
TM, Sparnins VL, Lam LK 1986. Char-
acteri zatio n of bacte rial mutagenicity
mediated by 13-hydroxy-ent-kaurenoic
acid (steviol) and several structurally-re-
lated derivatives and evaluation of poten-
tial to induce glutathione S-transferase in
mice. Mutation Res 169:93-103
Pomaret MM, Lavieille R 1931. Le priciple
a saveur sucree du kaa-hee-e (Stevia
re ba u di ana Bert oni ). IV . Qual que s
proprietes physiologiques du stevioside.
Bull Soc Chem Biol 13:1248-1253
Rebaudi O 1900. Note about el Caa-eee. Rev
Quimi Farma Buenos Aires 1:2-3
J Food Sci Technol, 2008, 45(6), 467–473
473
Savita SM, Sheela K, Sunanda S, Shankar
AG, R am kri sha na P 2004 . S tev ia
rebaudiana – A functional component for
food industry. J Hum Ecol 15:261-264
Sekihashi K, S aitoh H, Sasaki Y 2002.
Genotoxicity studies of stevia extract and
steviol by the comet assay. J Toxicol Sci
1:1-8
Soejarto DD, Kinghorn AD, Farnsworth NR
1982. Potential sweetening agents of plant
origin. III. Organoleptic evaluation of
stevia leaf herbarium samples for sweet-
ness. J Nat Prod 45:590-599
Starrat AN, Kirby CW, Pocs R, Brandle JE
2002. Rebaudioside F, a diterpene glyco-
side from Stevia rebaudiana. Phytochem
59:367–370
Suttajit M, Vinitketkaumnuen U, Meevatee
U, Buddhasukh D 1993. Mutagenicity and
human chromosomal effect of stevioside,
a swe etener from Stevia rebaudiana
Bertoni. E nviron Health Perspectives
101:53-56
Takanaka T, Kawashima K, Usami M, Sakami
K 1991. A teratological study of stevioside
administered orally to rats. Unpublished
report from Department of Pharmacology,
Biological Safety Research Center, Na-
tional Institute of Hygienic Sciences, Ja-
pan. Submitted to WHO by Ministry of
Health and Welfare, Food Chemistry Di-
vision, Japan
Toskulkao C, Chaturat L, Temcharoen P,
Glinsukon T 19 97. Acute toxicity of
stevioside, a natural sweetener, and its
metabolite, steviol, in several animal spe-
cies. Drug Chem Toxicol 20:31-44
Toskulkao C, Sutheerawa tt an an on M,
Piyachaturawat P 1995a. Inhibitory effect
of steviol, a metabolite of stevioside, on
glucose absorption in everted hamster in-
testine in vitro. Toxicol Lett 80:153-159
Tosk ulk ao C, Sut hee rawat ana non M,
Wanichanon C, Saitongdee P, Suttajit M
1995b. Effects of stevioside and steviol
on intestinal glucose absorption in ham-
sters. J Nutr Sci Vitaminol 41:105-113
Toyo da K, K aw ani shi T, Un eya ma C,
Takahashi M 1995. Re-evaluation of the
safety of a food additive (reported in fis-
cal 1994). A chronic toxicity/carcinoge-
nicity study of stevioside (a substance
extracted from stevia), Final report. Un-
published report from Division of Pathol-
ogy, Biological Safety Research Center,
National Institute of Health Sciences,
Japan. Submitted to WHO by Ministry of
Health and Welfare, Food Chemistry Di-
vision, Japan
Toyoda K, Matsui H, Shoda T, Uneyama C,
Takada K, Takahashi M 1997. Assessment
of the carcinogenicity of stevioside in F344
rats. Food Chem Toxicol 35:597-603
Usami M, Sakemi K, Kawashima K, Tsuda
M, Ohno Y 1995. Teratogenicity study of
stevioside in rats. Bull Nat Inst Hyg Sci
113:31-35
Usami M, Seino Y, Takai J, Nakahara H,
Seino S, Ikeda M, Imura H 1980. Effect
of cyclamate sodium, saccharin sodium
and stevioside on arginine-induced insulin
and glucagon secretion in the isolated
perfused rat pancreas. Horm Metab Res
12:705-706
WHO 2005. 63rd report of Joint FAO/WHO
Expert Committee on Food Additives.
World Health Organization, Geneva. Tech-
nical Report Series: 928 p 34-39
Wingard RE, Brown JP, Enderlin FE, Dale
JA, Ha le RL, Se it z CT 19 80 . Intestina l
degradatio n and absorp ti on of the g ly -
co sidic sweet eners stevi oside and
rebaudio si de A. Exp er ie ntia 36 :519-
520
Xili L, Chengjiany B, Eryi X, Reiming S,
Yuengming W, Haodong S, Zhiyian H
1992. Chronic oral toxicity and carcino-
genicity study of stevioside in rats. Food
Chem Toxicol 30:957-965
Yamada A, Ohgaki S, Noda T, Shimizu M
1985. Chronic toxicity of dietary stevia
extracts. Shokuin Eiseigaku Zasshi 26:169-
183
Yamamoto NS, Kelmer-Bracht AM, Ishii EL,
Kemmelmeier FS, Alvarez M, Bracht A
1985. Effect of steviol and its structural
analogues on glucose production and
oxygen u pt ake in ra t renal t ub ul es.
Experientia 41:55-57
Yodyingyuad V, Bunyawong S 1991. Effect
of stevioside on growth and reproduction.
Hum Reprod 6:158-165
Received 20 July 2007; revised 09 May 2008; accepted 11 May 2008
J Food Sci Technol, 2008, 45(6), 467–473
ATTENTION
Dear AFST(I) Members,
As a part of our efforts to update the membership database, we request you to kindly
furnish your name, address and area of specialization along with your e-mail id. Please
e-mail it to any of our AFST(I) e-mail ids:
afsti@sancharnet.in afstimys@dataone.in afstimys@yahoo.com
Kindly treat this very urgent as e-mail is the important medium of communication for
speedy interaction and it also cutsdown postal charges.
URGENT
URGENT
