Stevia
<p ><i><b>Stevia</b></i> is a <a href="http://en.wikipedia.org/wiki/Genus" title="Genus" >genus</a> of about 240 <a href="http://en.wikipedia.org/wiki/Species" title="Species" >species</a> of <a href="http://en.wikipedia.org/wiki/Herbaceous_plant" title="Herbaceous plant" >herbs</a> and <a href="http://en.wikipedia.org/wiki/Shrub" title="Shrub" >shrubs</a> in the sunflower family (<a href="http://en.wikipedia.org/wiki/Asteraceae" title="Asteraceae" >Asteraceae</a>), native to <a href="http://en.wikipedia.org/wiki/Subtropical" title="Subtropical" class="mw-redirect" >subtropical</a> and tropical regions from western North America to South America. The species <i>Stevia rebaudiana</i>, commonly known as <b>sweetleaf</b>, <b>sweet leaf</b>, <b>sugarleaf</b>, or simply <b>stevia</b>, is widely grown for its sweet leaves. As a sweetener and <a href="http://en.wikipedia.org/wiki/Sugar_substitute" title="Sugar substitute" >sugar substitute</a>, stevia's taste has a slower onset and longer duration than that of sugar, although some of its extracts may have a bitter or <a href="http://en.wikipedia.org/wiki/Licorice" title="Licorice" class="mw-redirect" >licorice</a>-like <a href="http://en.wikipedia.org/wiki/Aftertaste" title="Aftertaste" >aftertaste</a> at high concentrations.
With its <a href="http://en.wikipedia.org/wiki/Steviol_glycoside" title="Steviol glycoside" >steviol glycoside</a> extracts having up to 300 times the <a href="http://en.wikipedia.org/wiki/Sweetness" title="Sweetness" >sweetness</a> of sugar, stevia has garnered attention with the rise in demand for low-carbohydrate, low-sugar food alternatives. Because stevia has a negligible effect on <a href="http://en.wikipedia.org/wiki/Blood_glucose" title="Blood glucose" class="mw-redirect" >blood glucose</a>, it is attractive as a natural sweetener to people on <a href="http://en.wikipedia.org/wiki/Low-carbohydrate_diet" title="Low-carbohydrate diet" >carbohydrate-controlled diets</a>.
The availability of stevia varies from country to country. In a few countries, it has been available as a sweetener for decades or centuries; for example, stevia is widely used as a sweetener in Japan, where it has been available for decades. In some countries, health concerns and <a href="http://en.wikipedia.org/wiki/Political_controversies" title="Political controversies" class="mw-redirect" >political controversies</a> have limited its availability; for example, the United States banned stevia in the early 1990s unless labeled as a <a href="http://en.wikipedia.org/wiki/Dietary_supplement" title="Dietary supplement" >dietary supplement</a>,<sup id="cite_ref-McCaleb_1997_1_0-0" class="reference" ><a href="http://en.wikipedia.org/wiki/Stevia#cite_note-McCaleb_1997_1-0" >[1]</a></sup><sup id="cite_ref-1" class="reference" ><a href="http://en.wikipedia.org/wiki/Stevia#cite_note-1" >[2]</a></sup> but in 2008 it approved <a href="http://en.wikipedia.org/wiki/Rebaudioside_A" title="Rebaudioside A" class="mw-redirect" >rebaudioside A</a> extract as a food additive. Over the years, the number of countries in which stevia is available as a sweetener has been increasing. </p>
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In 2011, stevia was approved for use in the EU starting in early December, 2011.<sup id="cite_ref-eu-approved1_2-0" class="reference" ><a href="http://en.wikipedia.org/wiki/Stevia#cite_note-eu-approved1-2" >[3]</a></sup><sup id="cite_ref-eu-approved2_3-0" class="reference" ><a href="http://en.wikipedia.org/wiki/Stevia#cite_note-eu-approved2-3" >[4]<img alt="" src="http://upload.wikimedia.org/wikipedia/commons/thumb/2/26/Stevia_rebaudiana_flowers.jpg/220px-Stevia_rebaudiana_flowers.jpg" /></a></sup></p>
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For centuries, the <a href="http://en.wikipedia.org/wiki/Guarani_people" title="Guarani people" class="mw-redirect" >Guaraní peoples</a> of Paraguay used stevia, which they called <b >ka'a he'ê</b> ("sweet herb"), as a sweetener in <i ><a href="http://en.wikipedia.org/wiki/Yerba_mate" title="Yerba mate" >yerba mate</a></i> and <a href="http://en.wikipedia.org/wiki/Cardiotonic" title="Cardiotonic" class="mw-redirect" >cardiotonic</a> medicinal teas.<sup id="cite_ref-16" class="reference" ><a href="http://en.wikipedia.org/wiki/Stevia#cite_note-16" >[17]</a></sup> Current research has evaluated its effects on <a href="http://en.wikipedia.org/wiki/Obesity" title="Obesity" >obesity</a><sup id="cite_ref-nih_obesity_17-0" class="reference" ><a href="http://en.wikipedia.org/wiki/Stevia#cite_note-nih_obesity-17" >[18]</a></sup> and <a href="http://en.wikipedia.org/wiki/Hypertension" title="Hypertension" >hypertension</a>.<sup id="cite_ref-nih_bloodpressure_18-0" class="reference" ><a href="http://en.wikipedia.org/wiki/Stevia#cite_note-nih_bloodpressure-18" >[19]</a></sup><sup id="cite_ref-nih_hypertension_19-0" class="reference" ><a href="http://en.wikipedia.org/wiki/Stevia#cite_note-nih_hypertension-19" >[20]</a></sup> Stevia has a negligible effect on <a href="http://en.wikipedia.org/wiki/Blood_glucose" title="Blood glucose" class="mw-redirect" >blood glucose</a>, and may even enhance <a href="http://en.wikipedia.org/wiki/Glucose_tolerance" title="Glucose tolerance" class="mw-redirect" >glucose tolerance</a>;<sup id="cite_ref-curi_20-0" class="reference" ><a href="http://en.wikipedia.org/wiki/Stevia#cite_note-curi-20" >[21]</a></sup> it may be useful as a natural sweetener for <a href="http://en.wikipedia.org/wiki/Diabetes" title="Diabetes" class="mw-redirect" >diabetics</a> and others on <a href="http://en.wikipedia.org/wiki/Carbohydrate" title="Carbohydrate" >carbohydrate</a>-controlled diets.<sup id="cite_ref-gregersen_21-0" class="reference" ><a href="http://en.wikipedia.org/wiki/Stevia#cite_note-gregersen-21" >[22]</a></sup></p>