How it began
The plant ka'a he'e is native to Paraguay, in lands along the Parana River that are the traditional territory of Guarani peoples, including the Pai-tavytera. The Guarani used its licorice-flavored leaves as a medicinal herb. In the early twentieth century the Swiss naturalist Moises Bertoni, who worked in Paraguay, had the plant studied by European researchers, and it received the botanical name Stevia rebaudiana Bertoni. Bertoni recognized its potential as a powerful sweetener.
Before it existed
According to the account published by JSTOR Daily, the Guarani did not domesticate the plant before European contact and did not use it as their sweetener. When they sweetened foods they used honey. Elsewhere, sweetening relied on sugar, and from the twentieth century on artificial sweeteners such as saccharin, which Japan later banned over a possible link to cancer.
How it spread
Word of the herb spread slowly. In 1928 the Washington Post reported on the plant. The turning point came in Japan in the 1970s, after the government banned artificial sweeteners such as saccharin. Scientists there set out to address the leaf's bitter aftertaste, and by the end of 1973 forty-three research centers in the country were working on it. Stevia sweeteners were introduced in the United States market in 2011 and spread quickly through packaged foods and drinks.
Who pushed back
The commercial success of stevia raised a dispute over who benefits. In 2015 Guarani from Paraguay and Brazil demanded an access and benefit sharing contract from global corporations including Coca-Cola and Cargill, which Guarani leaders accused of using their traditional knowledge of ka'a he'e. They framed this as biopiracy under the 2010 Nagoya Protocol. Stevia does not fit Brazil's benefit sharing law, which excludes food resources, and Paraguay is not a party to the protocol.
Where it stands today
Stevia competes with sugar on global markets as a sweetener. Paraguay markets it as a national product through appellation procedures, stressing that the plant is endemic and tied to the country's soil, climate and vegetation, and presenting it as part of a mixed Guarani and Creole heritage. Guarani groups say that money from any future benefit sharing agreement would go to basic services and to regaining traditional lands along the Paraguayan and Brazilian border.
