Stevia is a source for alternative sweeteners: potential medicinal effects
The leaves from Stevia rebaudiana have been used as a source for natural sweeteners for decades in severalAsian countries. Stevioside, the major sweet compound from this plant, is 300 times sweeter than sucrose, but has a littlebitter aftertaste. This may be overcome via a simple enzymatic modification or via the use of another less abundantditerpenoid glycoside, rebaudioside A, which is devoid of such effect. Stevia refined extracts have been used in the USsince 1995 only in the dietary supplements market. In 2008, American FDA finally gave the approval for GenerallyRecognized as Safe (GRAS) status to highly purified rebaudioside A. France also approved rebaudioside A for food andbeverages in 2009. Most of the European Union countries are awaiting the EU approval on stevia products by 2011.Pharmacological studies show that all the glycosylated diterpenoids are degraded in the intestinal tract into their aglyconesteviol, therefore this compound is considered the pharmacologically active form. Global authorities (JECFA) have set 4mg/kg body weight as acceptable daily intake (ADI), expressed as steviol compound. Approval in other countries,however, will require further research on safety and toxicology of stevioside and related compounds. Unexpectedly, recentresearch suggests that stevioside and rebaudioside A may bear some therapeutic properties. Particularly, a decrease ofpostprandial glucose and glucagon levels as well as insulinotropic effects have been shown in several cellular and animalmodels. In human and animals, anti-hypertensive and immunomodulatory properties are also plausible. More recently, theantioxidant and anti-inflammatory effect of stevia-related compounds have significantly reduced the size of theatherosclerotic lesion in an animal model of metabolic syndrome. The increase of obesity in modern societies is drivingconsumer trends towards the use of non-caloric and natural sweeteners. Hence, a dramatic increase of the use of steviarelatedsweeteners is expected in substitution of synthetic sweeteners such as aspartame or saccharine. Additionally,stevioside and rebaudioside A, may provide medicinal properties to reduce obesity and cardiovascular risk.