[posted in several parts... combined........ BIG]
 
To answer your first question about the German Commission E monographs,
Sukie, much of the information from them is available on the Web on
assorted Web sites, already.  I use Henriette Kress' site (and her herb
list) a lot, and information from Commission E is often presented there.
I recommend Henriette's list and site highly, if you're not already using
them.
 
Stevia (stevia rebaudiana) is a small shrub native to portions of
Northeastern Paraguay and adjacent sections of Brazil.  It flourishes in
the sandy soil of this elevated terrain and may grow to a height of 80 cm
when it is fully mature.  While native Indians of the Guarani Tribe appear
to have used the leaves of this herb as a sweetener since pre-Columbian
times, it was not until 1887 when a South American natural scientist named
Antonio Bertoni first "discovered" it.  There is no report of any plant
toxicity to the consumers (Suttajit, 1993).  Stevia has been added to a
number of food products in Japan since the mid 1970s.  No indications of
any significant side effects have yet been reported after almost 30 years
of use.  Similarly, no reports of any adverse reactions to stevia have
been reported in the United States, according to the FDA.
 
Numerous animal tests (on mice and rats) have been conducted to determine
the safety of stevia.  In these tests, the scientists give progressively
higher doses of the substance until a lethal dose (LD) is reached where
50 percent of the test animals die.  This level is called the LD 50.
 
In the 1970s, several research groups attempted to find the lethal dose of
stevia (Kinghorn, 1985).  What they found was that, on average, a dose of
8,000 milligrams or more per kilogram of body weight was necessary to
achieve this LD 50.  Put into human terms, this is equivalent to a 70 kg
male ingesting more than two pounds of the extract.  In most cases, a glass
of water can be sweetened by less than 5 drops.  As can be expected, no
human has ever died from stevia overdose.  In a study published in Japan
in 1985, researchers determined that giving rats 550 mg/kg of body weight
every day of stevioside for 2 years did not cause any abnormalities.
 
Test have also been done to see if the ingestion of stevia causes
abnormalities in offspring.  In 1991, a study was done by researchers at
the Chulalongkorn University Primate Research Center in Bangkok, Thailand
(Yodyingyuad, 1991).  The researchers wanted to study the consequences of
daily ingestion of stevioside in hamsters and the effects on two subsequent
generations.  (Stevioside is the main active sweetening agent in the stevia
plant.) Three groups of 20 one-month-old hamsters (10 males and 10 females)
were force-fed daily with stevioside, while the fourth group stayed as the
controls.  (The fourth group did not get any stevioside.)
 
The experiment was started with 80 one-month-old hamsters, 40 of each sex,
each weighing between 30 and 50 grams.  The three groups received up to
2,500 mg/kg of stevia a day.  This dosage would be equivalent to a human
ingesting 150,000 mg ... about 300 times as much as the average human is
likely to ingest by sweetening their food.
 
Absolutely no significant abnormalities were found in any of the test
groups ..  including the one receiving 2,500 mg/kg.
 
Microscopic examination of reproductive tissues from all experimental
groups, both male and female, did not differ from the control group.  The
production of sperm was normal, even in the males who received the highest
dose of stevioside.
 
In the females, the ovaries of all the animals were perfectly normal.  No
abnormalities were found in growth, fertility and pregnancies in both
sexes.
 
In June 1997, the journal "Food and Chemical Toxicology" published an
article entitled "Assessment of the carcinogenicity of stevioside in
rats,"  This study was performed by Dr. K.  Toyoda and colleagues, from
the Division of Pathology, National Institute of Health Sciences in Tokyo,
Japan.  For a period of 104 weeks (two years), three groups of rats were
tested to receive either no stevioside (the controls), stevioside in a
concentration of 2.5 percent of their diet, and stevioside in a
concentration of 5 percent of their diet.  There were 50 male and 50 female
rats involved in the study.  All surviving rats were killed at the end of
week 108.  The results showed the body weight of the rats was less in those
who received the stevioside compared to the controls.  This makes sense
because stevioside has no calories.  When the organs and tissues of the
rats were examined under the microscope, there was no difference in the
controls and those on stevioside, except females on stevioside had a
decreased incidence of breast tumors, and the males had a lesser incidence
of kidney damage.  The researchers state, "It is concluded that stevioside
is not carcinogenic in F344 rats under the experimental conditions
described."
 
The natural sweetener stevioside, which is found in the plant stevia, has
been used for many years in the treatment of diabetes among Indians in
Paraguay and Brazil.  However, the mechanism for the blood glucose-lowering
effect remains unknown.  A study conducted at the Department of
Endocrinology and Metabolism, Aarhus University Hospital, Denmark, found
that stevioside enhances insulin secretion from mouse pancreatic islets in
the presence of glucose.  The researchers state, "Stevioside stimulates
insulin secretion via a direct action on pancreatic beta cells.  The
results indicate that the compounds may have a potential role as an
anti-hyperglycemic agent in the treatment of type 2 diabetes mellitus."
 
Reference: Jeppesen PB, et al.  Stevioside acts directly on pancreatic beta
cells to secrete insulin.  Metabolism 2000 Feb;49(2): 208-14.
 
Also, see:
 
REFERENCES
 
Bonvie, L., Bonvie, B., and Gates, D. 1997. The stevia story, a tale of
incredible sweetness and intrigue. B.E.D. Publications, Atlanta.
 
Das, S., Das, A.K., Murphy, R.A., Punwani, I.C., Nasution, M.D., and
Kinghorn, A.D. 1992.  Evaluation of the cariogenic potential of the
intense natural sweeteners stevioside and rebaudioside A. Caries Res. 26:
363-366.
 
Donalisio, M.G.R., Duarte, F.R., Pinto, A.J.D.A., and Souza, C.J. 1982.
Stevia rebaudiana.  Agronomico 34: 65-68.
 
Fors, A. 1995. A new character in the sweetener scenario. Sugar J. 58: 30.
 
Frederico, A.P., Ruas, P.M., Marinmorlaes, M.A., Ruas, C.F. and Nakajima,
J.N. 1996.  Chromosome studies in some Stevia (Compositae) species from
southern Brazil. Braz. J. Genet.  19: 605-609.
 
Hanson, J. R. and De Oliveira, B. H. 1993.  Stevioside and related sweet
diterpenoid glycosides.  Nat. Prod. Rep.  10: 301-309.
 
Kaneda, N., Kasai, R., Yamasaki, K. and Tanaka, O. 1977.  Chemical studies
on sweet diterpene-glycosides of Stevia rebaudiana: conversion of
stevioside into rebaudioside-A.  Chem. Pharm. Bull.  25: 2466-2467.
 
Katayama O., Sumida, T, Hayashi, H. and Mitsuhashi H. 1976.  The practical
application of Stevia and research and development data (English
translation).  I.S.U.  Company, Japan.  747 pp.
 
Kinghorn, A.D. 1992.  Food ingredient safety review: Stevia rebaudiana
leaves.  Herb Research Foundation, Boulder.
 
Kinghorn, A. D. and Soejarto, D. D.  1985.  Current status of stevioside
as a sweetening agent for human use.  Pages 1-52 in H.
 
Wagner, H. Hikino and N. R. Farnsworth, eds.  Economic and medicinal
plant research.  Academic Press, London.
 
Lewis, W.H. 1992.  Early uses of Stevia rebaudiana (Asteraceae) leaves as
a sweetener in Paraguay.  Econ.  Bot.  46: 336-337.
 
McGarvey, D.J., and Croteau, R.  1995.  Terpenoid metabolism.  Plant Cell
7: 1015-1026.
 
Pendergast, W.R. 1991. GRAS Affirmation Petition Number 2G0390.
 
Phillips, K.C.  1989.  Stevia: steps in developing a new sweetener.  Pages
1-43 in T.H.  Grenby ed.  Developments in sweeteners, Volume 3.  Elsevier
Applied Science, London.
 
Tanaka, O.  1982.  Steviol-glycosides: new natural sweeteners.  Trends
Anal. Chem. 1: 246-248.
 
Uneshi, H., Ise R., and Kobayashi, T. 1977.  Purification of a stevia
sweetening agent (English abstr.).  Jap.  Patent 54-030199.
 
Xiang, Z.P. 1983.  Stevia (partial English translation).  General Bureau
of State Farms, Heilongjiang, China.
 
Yodyingyuad, V., and Bunyawong, S. 1991.  Effects of stevioside on growth
and reproduction.  Human Reprod.  6: 158-165.
[Posted in FML issue 3146]