SteviaStevia rebaudiana

Did you know?

• Stevia's Guaraní name, ka'a he'ẽ, means "sweet herb." Reference books also spell it caa-ehe or ca-a-e^{[8, 9]}.

• Bertoni first named the plant Eupatorium rebaudianum in 1899, then moved it to the genus Stevia in 1905^{[1, 4]}.

• In 1931 two French chemists, M. Bridel and R. Lavieille, isolated the compounds behind the leaf's sweetness^[4].

• Stevioside, the most plentiful sweet compound in the leaf, is about 300 times sweeter than sugar, weight for weight^{[2, 3, 4]}.

• Japan was the first country to produce purified stevia extracts commercially, in the early 1970s^{[2, 3]}.

• Stevia belongs to the daisy family, the same family as sunflowers, marigolds and ragweed^{[2, 5]}.

Origins and history

Stevia is a tender perennial herb, about 1 to 3 feet (30 centimeters to 1 meter) tall, with small, oblong, aromatic leaves set in opposite pairs along the stems and clusters of small white flowers^{[2, 4]}. It grows wild in Paraguay and in the neighboring Brazilian states of Mato Grosso do Sul and Minas Gerais^{[1, 5]}.

Long before botanists knew of it, stevia was known to the Guaraní people of Paraguay. They added the dried leaves to yerba mate and other bitter drinks, and they have done so for centuries^{[2, 3, 4]}. Their name for it, ka'a he'ẽ, simply means "sweet herb"^{[8, 9]}. Western science learned of the plant from Moisés Santiago Bertoni, a Swiss-born botanist who had made his home in Paraguay. He described it in 1899 as Eupatorium rebaudianum, and in 1905 he moved it to the genus Stevia, giving it the name used today^{[1, 2, 4]}.

The chemistry followed. In 1931 the French chemists M. Bridel and R. Lavieille isolated the leaf's sweet compounds, the steviol glycosides^[4]. In the early 1970s Japan became the first country to produce purified stevia extracts commercially^{[2, 3]}, and the European Union approved purified steviol glycosides for use in food in 2011^{[2, 3]}. Stevia is now grown as a crop far beyond South America, from Central America to China^[4].

Traditional uses

Stevia's traditional use is simple, and its sweet compounds have been reviewed in detail by food-safety authorities in the US and Europe^{[2, 3, 6]}.

• Added to yerba mate

  For centuries, Guaraní people in Paraguay have added dried stevia leaves to yerba mate and other bitter teas.^{[2, 3, 4]}

• Whole leaf, not an extract

  In Guaraní tradition the whole dried leaf is used. Purified stevia extracts are a modern development, first produced commercially in Japan in the early 1970s.^{[2, 3]}

• Steviol glycosides

  Stevia leaf naturally contains steviol glycosides, the plant compounds responsible for its sweet taste.^{[3, 6]}

Plant compounds

Stevia's sweet taste comes from steviol glycosides, a family of plant compounds built on a core called steviol that carries one or more sugar units^[3]. The most abundant is stevioside, typically about 9 percent of the dried leaf^[3] and reported at anywhere from 6 to 18 percent^[4]; rebaudioside A comes next^[3]. The leaf also contains smaller amounts of related glycosides, such as rebaudiosides C, D and E, dulcoside A and steviolbioside^{[3, 6]}. Stevioside is about 300 times sweeter than sugar^{[2, 3, 4]}, and the FDA describes high-purity steviol glycosides as 200 to 400 times sweeter than table sugar^[6].