two recent warning studies on stevia toxicity on rats and bacteria, AP
Nunes et al, 2007 April, 2006 Dec, links to 18 positive abstracts from
2000 February to 2004 January: Murray 2007.05.03
http://groups.yahoo.com/group/aspartameNM/message/1419

At the end of this post, I link to my 5 previous reviews in 2005
August that give 18 full abstacts in PubMed on stevia toxicity from
2000 February to 2004 January, which do not find that stevia is
practically toxic to humans in ordinary use -- and give an opposite
positive abstract using the Comet assay in 2002 December, and then
share the conclusion from the full text of another study on
mutagenicity, T Terai et al 2002 July.


These two recent studies by a reputable mainstream academic research
team in Brazil, who publish similar toxicity studies on other
chemicals, used rats and bacteria to find negative effects, which
justify additional careful studies, to decide if the approval of
stevia should be reversed in Japan, South Korea, China, Brazil, and
Paraguay, or the maximum lifetime safe dose be set at a lower level.

The other recent studies on stevia in PubMed since 2004 January
include no negative safety studies and many about possible positive
therapeutic effects. I'm not going to try to master this expanding
and complex field, but just provide some useful orientation. Every
citizen has to find their own strategy for making practical decisions
about risk, and assessing information sources.

In mutual service, Rich Murray


Food Chem Toxicol. 2007 Apr; 45(4): 662-6. Epub 2006 Oct 27.
Analysis of genotoxic potentiality of stevioside by comet assay.

* Nunes AP,
* Ferreira-Machado SC,
* Nunes RM,
* Dantas FJ,
* De Mattos JC,
* Caldeira-de-Araujo A.

Departamento de Biofisica e Biometria, Universidade do Estado do
Rio de Janeiro, Instituto de Biologia Roberto Alcantara Gomes, Av 28
de Setembro, 87, 20551-030 Rio de Janeiro, RJ, Brazil.

Stevioside is a natural non-caloric sweetener extracted from
Stevia rebaudiana (Bertoni) leaves.

It has been widely used in many countries, including Japan, Korea,
China, Brazil and Paraguay,
either as a substitute for sucrose in beverages and foods or as a
household sweetener.

The aim of this work was to study its genotoxic potentiality in
eukaryotic cells.

Wistar rats were treated with stevioside solution (4mg/mL) through
oral administration (ad libitum) and the DNA-induced damage was
evaluated using the single cell gel electrophoresis (comet assay).

The results showed that treatment with stevioside generates lesions in
peripheral blood, liver, brain and spleen cells in different levels,
the largest effect being in liver.

Therefore, these undesired effects must be better understood, once the
data present here point to possible stevioside mutagenic properties.
PMID: 17187912



Mol Cell Biochem. 2006 Dec; 293(1-2):187-92. Epub 2006 Jun 28.
Biological effects of stevioside on the survival of Escherichia
coli strains and plasmid DNA.

* Nunes AP,
* De Mattos JC,
* Ferreira-Machado SC,
* Nunes RM,
* Asad NR,
* Dantas FJ,
* Bezerra RJ,
* Caldeira-de-Araujo A.

Departamento de Biofisica e Biometria, Universidade do Estado do
Rio de Janeiro, Instituto de Biologia Roberto Alcantara Gomes, Avenida
28 de Setembro #87, Rio de Janeiro, RJ 20551-030, Brazil.

Stevioside is widely used daily in many countries as a non-caloric
sugar substitute.

Its sweetening power is higher than that of sucrose by approximately
250-300 times, being extensively employed as a household sweetener, or
added to beverages and food products.

The purpose of this study was to ascertain stevioside genotoxic and
cytotoxic potentiality in different biological systems, as its use
continues to increase.

Agarose gel electrophoresis and bacterial transformation were employed
to observe the occurrence of DNA lesions.

In addition to these assays, Escherichia coli strains were incubated
with stevioside so that their survival fractions could be obtained.

Results show absence of genotoxic activity through electrophoresis and
bacterial transformation assays and drop of survival fraction of E.
coli strains deficient in rec A and nth genes, suggesting that
stevioside
(i) is cytotoxic;
(ii) could need metabolization to present deleterious effects on
cells;
(iii) is capable of generating lesions in DNA and pathways as base
excision repair, recombination and SOS system would be important to
recover these lesions.
PMID: 16804638


This positive study also used the Comet assay to assess genotoxicity:

J Toxicol Sci. 2002 Dec; 27 Suppl 1: 1-8.
[Genotoxicity studies of stevia extract and steviol by the comet
assay]
[Article in Japanese]
Sekihashi K, Saitoh H, Sasaki Y. yfsasaki-c@...
Safety Research Institute for Chemical Compounds Co., Ltd., 363-24
Shin-ei,
Kiyota-ku, Sapporo 004-0839, Japan.

The genotoxicity of steviol, a metabolite of stevia extract, was
evaluated
for its genotoxic potential using the comet assay.

In an in vitro study, steviol at 62.5, 125, 250, and 500 micrograms/ml
did
not damage the nuclear DNA of TK6 and WTK1 cells in the presence and
absence
of S9 mix.

In vivo studies of steviol were conducted by two independent
organizations.
Mice were sacrificed 3 and 24 hr after one oral administration of
steviol at
250, 500, 1000, and 2000 mg/kg.

DNA damage in multiple mouse organs was measured by the comet assay as
modified by us.

After oral treatment, stomach, colon, liver, kidney and testis DNA
were not
damaged.

The in vivo genotoxicity of stevia extract was also evaluated for its
genotoxic potential using the comet assay.

Mice were sacrificed 3 and 24 hr after oral administration of stevia
extract
at 250, 500, 1000, and 2000 mg/kg.

Stomach, colon and liver DNA were not damaged.

As all studies showed negative responses, stevia extract and steviol
are
concluded to not have DNA-damaging activity in cultured cells and
mouse
organs. PMID: 12533916




" In this report, we have roughly estimated the influence of
the mutagenicity of steviol, used as low calorie sweetener in
our daily life, in comparison to that of AF2, which was previously
used as an authorized food preservative. In the case of
a cup of coffee, with the assumption of the common size of
commercial individually packed sugar in Japan as ranging
from three to five grams, the average amount of sugar can be
assumed as four grams per cup. To provide similar sweetness,
only 16 mg of stevia is necessary as the sugar substitute
for the same cup of coffee. According to the specific mutagenic
values of our experimental data, as shown in Table 1,
only 0.6 mg stevia is necessary to indicate the similar
strength in mutagenicity under the absence of S9 mixture as
that given by 16 mg of stevia. Using values for AF2, whose
levels were permitted up to 2 mg for preserving 100 g of fish
sausage products from 1965 to 1974 in Japan, the mutagenic
activity given by 2 mg of AF2 is calculated to be equivalent
to 48 g of stevia, which translates to 3000 cups of coffee.

>From this simulation, the genetic toxicity of stevia can be regarded
as negligible and safe, as long as we limit its use in
ordinary amount for our daily life. Although further studies,
such as the effect of heating on the activity of stevia, or the
metabolic fate of its lactone derivatives in our body are necessary,
the present paper suggests that there are no serious
genotoxic problem with the daily usage of this low-calorie
sweetener. "

Chem Pharm Bull (Tokyo). 2002 Jul; 50(7): 1007-10.
Mutagenicity of steviol and its oxidative derivatives in
Salmonella typhimurium TM677.

* Terai T,
* Ren H,
* Mori G,
* Yamaguchi Y,
* Hayashi T.

Department of Applied Chemistry, Osaka Institute of Technology,
Japan. terai@...

Stevioside is natural non-caloric sweetner isolated from Stevia
rebaudiana BERTONI, which has been used as a non-caloric sugar
substitute in Japan.

Pezzuto et al. demonstrated that steviol shows a dose-dependent
positive response in forward mutation assay using Salmonella
typhimurium TM677 in the presence of metabolic activation system
(Aroclor induced rat liver S9 fraction).

Our studies were carried out to identify the genuine mutagenic active
substance from among the eight steviol derivatives.

Steviol indicate almost similar levels of mutagenicity under the
presence of S9 mixture, as reported by Pezzuto et al.

15-Oxo-steviol was found to be mutagenic at the one tenth the level of
steviol itself under the presence of S9 mixture.

Interestingly, specific mutagenicity of the lactone derivative under
the presence of S9 mixture was ten times lower than that of the
lactone derivative without the addition of S9 mixture.
PMID: 12130868

http://www.jstage.jst.go.jp/article/cpb/50/7/50_1007/_article/-char/en
free full text
http://www.jstage.jst.go.jp/article/cpb/50/7/1007/_pdf 68 KB

Tadamasa Terai 1),
Huifeng Ren 2),
Go Mori 1),
Yoshihito Yamaguchi 1) and
Tetsuhito Hayashi 2)
1) Department of Applied Chemistry, Osaka Institute of Technology
5-16-1 Omiya, Asahi-ku, Osaka 535-8585, Japan: and
2) Department of Food Science and Technology, Tokyo University of
Fisheries
4-5-7 Konan, Minato-ku, Tokyo 108-8477, Japan.
(Received March 19, 2002) (Accepted May 7, 2002)

References

1) Wood H. B., Allerton R., Diehl H. W., Fletcher H. G., J. Org.
Chem., 20, 875-883 (1955).

2) Akashi H., Yokoyama Y., Shokuhinkougyo, 10, 34-43 (1975).

3) Xili L., Chengjiany B., Eryi X., Fed. Chem. Toxicol., 30, 957-965
(1992).

4) Kato R., Gillette J. R., J. Pharmacol. Exp. Ther., 150, 285-291
(1965).

5) Wingard R. E., Jr., Brown J. P., Enderlin F. E., Dale J. A., Hale
R. L., Seitz C. T., Experientia, 36, 519-520 (1980).

6) Pezzuto J. M., Compadre C. M., Swanson S. M., Nanayakkara N. P. D.,
Kinghorn A. D., Proc. Natl. Acad. Sci. U.S.A., 82, 2478-2482 (1985).

7) Suttajit M., Vinitketkaumnuen U., Meevatee U., Buddhasukh D.,
Environ. Health Perspect., 101, 53-56 (1993).

8) Matsui M., Matsui K., Kawasaki Y., Oda Y., Noguchi T., Kitagawa Y.,
Sawada M., Hayashi M., Nohmi T., Yoshihira K., Ishidate M., Jr.,
Sofuni T., Mutagenesis, 11, 573-579 (1996).

9) Yoshioka I., Saijoh S., Warers J. A., Kitagawa I., Chem. Pharm.
Bull., 20, 2500-2502 (1972).

10) Terai T., Nippon Nogeikagaku Kaishi, 63, 1119-1121 (1989).

11) Skopek T., Liber H. L., Kaden D. A., Thilly W. G., Proc. Natl.
Acad. Sci. U.S.A., 75, 4465-4469 (1978).

12) Skopek T., Liber H. L., Krolewski J. J., Thilly W. G., Proc. Natl.
Acad. Sci. U.S.A., 75, 410-414 (1978).

13) Takagi Y., Goto S., Murata T., Matsushita H., Lewtas J., Taiki
Osen Gakkaishi (J. Jpn. Soc. Air Pollution), 23, 24-31 (1988).

14) Ren H., Hayashi T., Goto S., Ohkubo T., Endo H., Watanabe E.,
Nippon Suisan Gakkaishi (J. Jpn. Soc. Fish. Sci.), 63, 90-96 (1997).



http://groups.yahoo.com/group/aspartameNM/message/1201
here's three more stevia abstracts: lowers blood pressure, Lee CN 2001
Dec: antiviral, Takashashi K 2001 Jan: antihyperglycemic, Jeppesen
PB,
2000 Feb: Murray 2005.08.07

Planta Med. 2001 Dec; 67(9): 796-9.
Inhibitory effect of stevioside on calcium influx to produce
antihypertension.
Lee CN, Wong KL, Liu JC, Chen YJ, Cheng JT, Chan P.
Department of Medicine, Taipei Medical University-Wan Fang Hospital,
Wen Shan, Taipei, Taiwan.

Antiviral Res. 2001 Jan; 49(1): 15-24.
Analysis of anti-rotavirus activity of extract from Stevia rebaudiana.
Takahashi K, Matsuda M, Ohashi K, Taniguchi K, Nakagomi O, Abe Y,
Mori S, Sato N, Okutani K, Shigeta S.
Department of Microbiology, School of Medicine, Fukushima Medical
University, 1 Hikarigaoka, Fukushima-shi 960-1295, Japan.
k-t...@...

Metabolism. 2000 Feb; 49(2): 208-14.
Stevioside acts directly on pancreatic beta cells to secrete insulin:
actions independent of cyclic adenosine monophosphate and
adenosine triphosphate-sensitive K+-channel activity.
Jeppesen PB, Gregersen S, Poulsen CR, Hermansen K.
Department of Endocrinology and Metabolism, Aarhus University
Hospital, Denmark.


http://groups.yahoo.com/group/aspartameNM/message/1201
here's three more stevia abstracts: lowers blood pressure, Lee CN 2001
Dec: antiviral, Takashashi K 2001 Jan: antihyperglycemic, Jeppesen PB,
2000 Feb: Murray 2005.08.07

http://groups.yahoo.com/group/aspartameNM/message/1199
yet three more stevia abstracts: mutagenic in bacteria, Terai T, 2002
July: lowers blood pressure in rats, Hsu YH, 2002 Jan:
antihyperglycaemic, insulinotropic and glucagonostatic benefits in
rats,
Jeppesen PB 2002 Jan; Murray 2005.08.07

http://groups.yahoo.com/group/aspartameNM/message/1198
three more stevia abstracts: no genotoxicity in mice, Sekihashi K,
Saitoh H, Sasaki Y 2002 Dec: lowers blood pressure in dogs,
Liu JC 2003 Jan: inhibits tumors in mice, Yasukawa K 2002 Nov:
Murray 2005.08.05

http://groups.yahoo.com/group/aspartameNM/message/1197
three abstracts on expert stevia research: hypertension, Chan P
2000 Sept; microflora, Gardana C 2003.10.22; helps blood pressure
and glucose level, Jeppesen PB 2003 Mar: Murray 2005.08.05

http://groups.yahoo.com/group/aspartameNM/message/1196
Alan in alt.support.diabetes re Stevia and Glycemic and Hypertension
Control
2004.05.14: 2 year large scale blood pressure study, Hsieh MH, 2003
Nov:
insulin in muscles, Lailerd N 2004 Jan: glucose in diabetics,
Gregersen S
2004 Jan: Murray 2005.08.04

http://groups.yahoo.com/group/aspartameNM/message/1179
Stevia (stevioside) is safe: Prof. Jan M.C. Geuns: Murray 2005.07.06

http://groups.yahoo.com/group/aspartameNM/message/1084
26 stevia safety abstracts since 1993: aspartame vs stevia debate on
alt.support.diabetes, George Schmidt, OD: Murray 2004.05.25 rmforall
///////////////////////////////////////////////////////////


aspartame (methanol, formaldehyde) toxicity research summary: Rich
Murray 2007.05.03
http://groups.yahoo.com/group/aspartameNM/message/1404

One liter aspartame diet soda, about 3 12-oz cans,
gives 61.5 mg methanol,
so if 30% is turned into formaldehyde, the formaldehyde
dose of 18.5 mg is 37 times the recent EPA limit of
0.5 mg per liter daily drinking water for a 10-kg child:
www.epa.gov/teach/chem_summ/Formaldehyde_summary.pdf
2007.01.05 [ does not discuss formaldehyde from methanol
or aspartame ]
http://www.epa.gov/teach/teachsurvey.html comments
teach@...


"Of course, everyone chooses, as a natural priority,
to actively find, quickly share, and positively act upon
the facts about healthy and safe food, drink, and
environment."

Rich Murray, MA Room For All rmforall@...
505-501-2298 1943 Otowi Road, Santa Fe, New Mexico 87505

http://groups.yahoo.com/group/aspartameNM/messages
group with 74 members, 1,419 posts in a public, searchable archive
http://RMForAll.blogspot.com

http://groups.yahoo.com/group/aspartameNM/message/1340
aspartame groups and books: updated research review of
2004.07.16: Murray 2006.05.11


http://groups.yahoo.com/group/aspartameNM/message/1395
Aspartame Controversy, in Wikipedia democratic
encyclopedia, 72 references (including AspartameNM # 864
and 1173 by Murray), brief fair summary of much more
research: Murray 2007.01.01


Dark wines and liquors, as well as aspartame, provide
similar levels of methanol, above 120 mg daily, for
long-term heavy users, 2 L daily, about 6 cans.

Within hours, methanol is inevitably largely turned into
formaldehyde, and thence largely into formic acid -- the
major causes of the dreaded symptoms of "next morning"
hangover.

Fully 11% of aspartame is methanol -- 1,120 mg aspartame
in 2 L diet soda, almost six 12-oz cans, gives 123 mg
methanol (wood alcohol). If 30% of the methanol is turned
into formaldehyde, the amount of formaldehyde, 37 mg,
is 18.5 times the USA EPA limit for daily formaldehyde in
drinking water, 2.0 mg in 2 L average daily drinking water.
///////////////////////////////////////////////////////////