A natural sweetener — kaa he-he

Stevia rebaudiana is a bushy South American herb, native to Paraguay. It was known as “kaa he-he” (sweet herb) by the native Guarani Indians, who used it centuries ago to sweeten food and drinks. Glycosides extracted from the leaves have up to 300 times the sweetness of sugar.

It is currently banned in the EU (except in France), which authorised a two-year trial in 2009 for certain stevia extracts. There have been concerns over the safety of stevia products with regards to mutagenicity and effects on male fertility, but the UK Food Standards Agency simply states that “they did not pass EU safety assessments” and prohibits the importation of stevia products and steviosides.

However, it has been used for decades in Japan and many other Asian countries, and is approved in Australia, New Zealand and Switzerland.

A breakthrough for the global stevia market came in 2008 when the US Food and Drug Administration approved for use stevia products containing stevial glycosides of at least 95 per cent purity. Since then, stevia-based sweeteners have been adopted by several of the familiar food and drinks giants. A major attraction is that the products can be labelled as “natural”.

The most important glycoside is rebaudioside-A, which has the advantage over most other high intensity sweeteners of being heat and acid stable, allowing it to be used in acidic fruit juices and pasteurised dairy products.

The herb has courted controversy, with suggestions in some quarters that the US import ban, imposed in the early 1990s, was a political move resulting from pressure from the multi-million dollar sweetener industry because, since the product is natural, production cannot be controlled by patent.

China is now the largest producer of stevia, but it is important as a cash crop in other developing countries, including Paraguay, where the government is urging farmers to stop growing marijuana, and stevia is seen as an attractive alternative now that the potentially huge US market is open.