Re: steviosides mutagenic? Apparently not.

[Guest guest]

Hanneke, I looked through a number of articles that looked as if they would have something to say on this subject, and I can't find a single one that says that it is dangerous in any way. It looks to me as if someone has remembered wrongly or read without understanding, or just read some headings without reading the articles.

I'm glad I looked this up, as I had forwarded the info to a health buddy, who intended to pass it on to a group. So I had better undo the damage as quickly as I can!

Rowena

Mutagenicity The mutagenicity of crude stevia extract, stevioside, ... Aroclor 1254-pretreated rats, 15-oxosteviol was found to be the mutagenic product in ...links.jstor.org/sici?sici=0091-6765(199310)101%3C53%3AMAHCEO%3E2.0.CO%3B2-Z -

Abstract

Leaves of Stevia rebaudiana Bertoni have been popularly used as a sweetener in foods and beverages for diabetics and obese people due to their potent sweetener stevioside. In this report, stevioside and steviol were tested for mutagenicity in Salmonella typhimurium strains TA98 and TA100 and for chromosomal effects on cultured human lymphocytes. Stevioside was not mutagenic at concentrations up to 25 mg/plate, but showed direct mutagenicity to only TA98 at 50 mg/plate. However, steviol did not exhibit mutagenicity in either TA98 or TA100, with or without metabolic activation. No significant chromosomal effect of stevioside and steviol was observed in cultured blood lymphocytes from healthy donors (n = 5). This study indicates that stevioside and steviol are neither mutagenic nor clastogenic in vitro at the limited doses; however, in vivo genotoxic tests and long-term effects of stevioside and steviol are yet to be investigated.

(This reads to me as if it was mutagenic only to Salmonella!)

http://books.google.com/books?id=nzRU9byD63MC & pg=PA170 & lpg=PA170 & dq=stevia+mutagenic+rats & source=web & ots=t6eMxsFl_J & sig=RVR5KizOB6OZjqWOCDzODvI4hic#PPA171,M1 Even here it doesn't really seem to be saying it IS mutagenic full stop. Says benefits outweigh risks.

http://www.uspharmacist.com/oldformat.asp?url=newlook/files/Comp/stevia2.html & pub_id=8 & article_id=634 Stevia is an herb that is used extensively in various areas of the world (without documentation of long term use and effects) as a noncaloric sugar substitute. Various reports in animals and humans indicate that the safety of this herb is not yet completely determined. The current status of using this herb in the U.S. is as a "dietary supplement." Until further information is available, pharmacists should be advised to conform to the FDA recommendation when counseling patients about this herb. Specifically, mild to moderate use as a supplement should be safe, but increased use for other pharmacological effects may not be warranted.

(So the old matter of not proven to be safe nor unsafe either).

Complete Stevia information from Drugs.com

Stevia has been shown to not be mutagenic or genotoxic. ... 1 Chronic administration of stevia to male rats had no effect in fertility vs. controls. ...www.drugs.com/npp/stevia.html

Diabetes Animal data Stevia may be helpful in treating diabetes. Steviol, isosteviol, and glucosilsteviol decreased glucose production in rat renal cortical tubules. Oral use of stevia extract in combination with chrysanthemum to manage hyperglycemia has been discussed.

Clinical data Aqueous extracts of the plant increased glucose tolerance in 16 healthy volunteers, as well as markedly decreasing plasma glucose levels

Stevia's effects on blood pressure have been reported. The plant displayed vasodilatory actions in both normo- and hypertensive animals. Stevia has also produced decreases in blood pressure, and has increased diuretic and natriuretic effects in rats. The plant has cardiotonic actions, which normalize blood pressure and regulate heartbeat. 1

Clinical data Research reveals no clinical data for the use of stevia for hypertension.

Other uses Stevia extract has exhibited strong bactericidal activity against a wide range of pathogenic bacteria, including certain E. coli strains. Steviol is mutagenic toward salmonella and other bacterial strains, under various conditions, and toward certain cell lines. Stevia may also be effective against Candida albicans . 1 One report addresses stevia's role against dental plaque.

Certain metabolic aspects of stevioside have been described, including rat liver effects, and cell membrane transport.

Adverse Reactions

No major contraindications, warnings, or side effects have been documented.

Toxicology

Stevia has been shown to not be mutagenic or genotoxic. One report indicates that constituents of stevioside and steviol are not mutagenic in vitro. Stevioside was found to be nontoxic in acute toxicity studies in a variety of laboratory animals. Chronic administration of stevia to male rats had no effect in fertility vs. controls. Another report concludes that stevioside in high doses affected neither growth nor reproduction in hamsters of both sexes.

http://alternativehealing.org/stevia.htm

The Committee noted a number of shortcomings in the information available on stevioside. In several studies, the material tested (stevioside or steviol) was poorly specified or of variable quality, and no information was available on other constituents or contaminants. Furthermore, no studies of metabolism of stevioside and steviol in humans were available. In addition, data on long-term toxicity and carcinogenicity were available for stevioside in only one species. The mutagenic potential of steviol has been tested sufficiently only in vitro.

In view of the absence of information for the elaboration of specifications for stevioside and since the evaluation of the available toxicological data revealed several limitations, the Committee was unable to relate the results of the toxicological investigations to the commercial product and could not allocate an ADI to stevioside.

Before reviewing stevioside again, the Committee considered that it would be necessary to develop specifications to ensure that the material tested was representative of the commercial product. Further information on the nature of the substance that was tested, data on the metabolism of stevioside in humans and the results of suitable in vivo genotoxicity studies with steviol would also be necessary.

A toxicological monograph was prepared. No specifications were prepared as no information was forthcoming.

http://www.cookingwithstevia.com/toxic.html

All of these studies showed negative results. Pezzuto et. al. (1985) demonstrated that steviol, the aglycone of stevioside, obtained by enzymatic hydrolysis, is mutagenic to Simonela typhimurium when evaluated in the presence of a 9000 x g supernatant fraction derived from livers of Aeroclor 1254 pretreat rats and addition of NADPH. They showed also that unmetabolized steviol was not active. Stevioside and isosteviol are inactive. Pezzuto et. al. (1986) also showed that steviol did not induce the activating 9000 x g supernatant metabolic systems of glutathione~S~transferase in mice. This evidence eliminates the possibility of mutagenic effects in animal tissues.

http://www.chem2pharm.com/index/herbal_steviosides C. Mutagenicity Stevia extracts have been extensively tested for their mutagenic activity. By using various strains of Salmonella typhimurium or E. coli either in the presence or absence of activating systems, one or more of these substances have been reported as non-mutagenic in laboratory tests in Brazil, Japan and the United States.

Joe, would you have any further references to this please/ Having read something is not quite the same as having a solid reference to a study.I know that for a long time stevia wasn't allowed into the US of A but that was politically motivated because of the competition with aspartame.A reference would be really appreciated.. if not the statement as such sounds more like fear mongering.Hanneke