Stevia
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| Stevia | ||||||||||||||
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| Stevia rebaudiana |
Stevia (Stevia rebaudiana Bertoni) is a shrub belonging to the Asteraceae (sunflower) family of plants. It is widely used as a sweetener in Japan, and is available in the US and Canada as a health food supplement. Originating in South America, it is found in the wild in semi-arid habitats ranging from grassland to mountain terrain. For centuries, the Guarani indios of Paraguay and Brazil used stevia, which they called ka'a he'ê (sweet herb) , as a sweetener in yerba mate and medicinal teas for treating such conditions as obesity, high blood pressure, and heartburn. It has recently seen greater attention with the rise in demand for low-carb, low-sugar food alternatives.
In 1931, French chemists isolated the glycosides that give stevia its sweet taste. These extracts were named steviosides and rebaudiosides. These compounds are 250–300 times sweeter than sucrose (ordinary table sugar). Stevia's sweet taste has a slower onset and longer duration than sugar's, and especially at high concentration, it has bitter and and liquorice-like off-tastes. Stevia does not significantly alter blood glucose, and so can be safely consumed by diabetics.
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Commercial sweetener use
In the early 1970s, the Japanese began cultivating stevia as an alternative to artificial sweeteners such as cyclamate and saccharin, which were at that time suspect carcinogens. The plant's leaves, the aqueous extract of the leaves, and purified steviosides are used as sweeteners. Stevia sweeteners have been produced commercially in Japan since 1977 and are widely used in food products, soft drinks, and for table use. Japan currently consumes more stevia than any other country; there, stevia accounts for 40% of the sweetener market.
Today, stevia is cultivated and used in food elsewhere in east Asia, including in China (since 1984), Korea, Taiwan, Thailand, and Malaysia, in part of South American (Brazil, Paraguay), and Uruguay and in Israel. China is the world's largest exporter of the stevia extract, stevioside.
Health concerns
A European health study found that stevioside depressed the virility of male mice.[1] (http://archive.food.gov.uk/pdf_files/stevia.pdf) It has also been reported that steviol, one of the principal metabolites of stevioside, is a mutagen.[2] (http://cis.nci.nih.gov/fact/3_19.htm) Based on these findings, the European Commission banned stevia's use in food in the European Union pending further research. It is also banned in Singapore and Hong Kong.[3] (http://www.legco.gov.hk/yr01-02/english/sec/library/0102fs04e.pdf). Additional animal tests have shown mixed results in terms of toxicology and adverse effects of stevia extract.
Stevia proponents point out that stevia has been used by millions of users in modern countries such as Japan for thirty years, with no reported or known harmful effects on humans.
Limits on use
In 1991, at the request of an aspartame manufacturer, the United States Food and Drug Administration labelled stevia as an "unsafe food additive," and restricted its import. The FDA's stated reason was "toxicological information on stevia is inadequate to demonstrate its safety."[4] (http://www.fda.gov/ora/fiars/ora_import_ia4506.html) This ruling was controversial, as stevia proponents pointed out this designation goes against the FDA's guidelines, under which any natural substance used prior to 1958 with no reported adverse effects should be recognized as safe. After Stevia was banned, several of members of the FDA board left their jobs. They were all hired at the Nutrasweet Co. in higher pay jobs, according to National (government) records. This has been criticized as a legal bribe by Nutrasweet to the FDA, to ban Stevia (Nutrasweet's main competitor then) in the U.S.
In 1995, the FDA revised its stance to permit stevia to be used as a "dietary supplement," although not as a food additive. Currently, it is legal to import, grow, sell and consume Stevia products in the United States if it is contained within or labelled for use as a dietary supplement.
Similarly, in Australia and Canada, stevia has been approved only for dietary supplements. However stevia has been grown on an experimental basis in Ontario since 1987 for the purpose of determining the feasibility of growing the crop commercially.
External links
- Stevia.net (http://www.stevia.net)
- Hong Kong (http://www.legco.gov.hk/yr01-02/english/sec/library/0102fs04e.pdf) (PDF file)
- Mixed results (http://cis.nci.nih.gov/fact/3_19.htm) NIH
- European commisssion (http://www.herbmed.org/Herbs/Herb122.htm)de:Stevia rebaudiana