Stevia is a plant which can be used alternatively to sugar as a sweetener. It is naively growing in South America, where it is used as sweetener by the natives since centuries. Its extracts can be up to 300 times sweeter then normal sugar. In 1987 it was discovered by a Swiss botanist (Moisés Santiago Bertoni). But from then on it took pretty long to make it more popular in the western world. The first country which thought about Stevia as a sugar substitute was Japan. They made their first cultivating experiments in the 1950's, and started to use it as complementary food and sweetener in the 1970's. In 1980 the consumption has already risen up to 2000 tons of Stevia per year.
So far for the far east, but in Europe and North America Stevia was, and still is mainly prohibited, due to concerns about side effects of Stevia, especially about steviol, the metabolized aglycone of stevioside,what is the main component of Stevia. Some studies with animals, especially rats, in the 1980's affirmed that the steviol would be mutagenic. But these studies were hardly criticized, and considered not to be transferable to the human by the critics. If a human ate the proportional amount of Stevia which one rat in the experiments ate, he would have eaten a half of his body weight in Stevia leaves. In these amounts even sugar would be very unhealthy. Because of these concerns it is still unapproved as consumable in the most parts of the western world, and can only be sold as a beauty product, in some places in diet food or as tea.
But to come back to the title, I will now talk about the health benefits of Stevia. Some studies say that it is effective against dental caries and the accumulation of plaque, in opposite to sugar, what is doing harm to the teeth. Some other studies affirm that Stevia does not cause a raise of the blood sugar, but even lowers it. So it is perfectly usable as a sugar substitute for diabetics and better then other artificial sweeteners like aspartame or sucralose (Splenda), as it is natural and not chemical. What makes it even more suitable for dietary foods, is the fact that the extract of Stevia literally has got zero calories. Stevia also contains about 100 minerals and vitamins, but in the amounts consumed by the human, the effects are pretty negligible.
As mentioned above, the negative side effects are literally inexistent, so the health organizations of the European Union and the USA should really reconsider the prohibition of Stevia, or enforce some real studies about it, to clear the true risks of Stevia consumption. Then it could be used for dietary food and generally as sugar supplement and to replace the artificial sweeteners in the future.
