Stevia

Stevia also known as sweet leaf or sugar leaf is a South American herb used as a sweetener. Stevia when used as a sweetener has a slow onset and a longer duration than sugar. At high concentrations some of its extracts might have bitter or licorice like after taste. Stevia extract have up to 300 times sweetness of sugar. Stevia is an attractive natural sweetener option for diabetics as it has negligible effect on the blood sugar level and even enhances glucose tolerance.

It has also gained attention due to its positive effects in the treatment of obesity and high blood pressure with the help of carbohydrate controlled diets and low sugar food alternatives. However due to some health and political controversies stevia is not readily available on the shelves of the superstore in many countries as the Food and Drug Administration has turned down the request of its use in foods in U.S. Although it is not used as a food addictive in most of the countries, it is widely used as a dietary supplement (FDA has little control in this field) in many countries and in Japan it is widely used as a natural sweetener.

Stevioside and rebaudioside are the two glycosides responsible for the sweet taste of stevia. They were isolated in 1931 by a french chemist and are 250-300 times sweeter than table sugar sucrose, also they were heat stable, pH stable and non-fermentable and thus can be used in many stevia recipes that are low in carbohydrates.

Stevia and stevia leaf has been consumed for many years without any scientific research for its safety and effectiveness (in Japan it is used for more than 30 years with out any reported averse effect). Stevia when consumed in small amounts (1 or 2 serving per day in tea or coffee) is considered safe, however when consumed in larger amounts (if allowed to use it as a food addictive in diet sodas or other products) it might pose a public health threat. Stevia may affect the male reproductive organ system by reducing the sperm count, increased proliferation of the cells in the testicles and may even cause infertility problems. Stevia is also associated with cancer as it is believed that it may get converted in to a mutagenic compound and may promote cancer. It may even interfere with the energy metabolism in the body. However to prove these effect more human based scientific researches are required. It is very important to derive the standard safety dose of stevia and clear these health controversies before it is approved to be used as a food addictive or a sweetener in products widely used by people.

Submitted on September 4, 2008