By now, you have probably heard of stevia. You may have seen it in health food stores. There is also much information on the web and even a book that has been written about it. Stevia is a shrub found in South America. The leaf contains substances that are much sweeter than sugar and yet contain no calories. Although it is used in some other countries as a no-calorie sweetener, it can not be used in foods in the United States because it has not been proven safe for food use by the FDA. Since supplements do not follow the same stringent FDA regulations that food additives do, it is often sold in health food stores as a natural supplement.  

Currently, supplements containing stevia claim the product can help maintain a healthy blood pressure and glucose levels. Although, most labels state that stevia should not be used by pregnant women, children or people with low blood pressure, stevia is widely marketed as a supplement in the U.S. and Canada. Although the U.S., Canada and many European countries have not approved stevia as a safe food additive, many other countries including Brazil, Japan, China and others have approved it for use in food.  

The FDA has chosen not to approve stevia for use as a sweetener because of some studies that show stevia may cause cancer and reduce fertility. Currently, the FDA lists stevia as an ‘unsafe food additive’ as no one has produced significant safety evidence for its use in food. However, because of the small amount of data surrounding its possible  downfalls, many databases list stevia as a safe  substance. Please note: this author is not necessarily in agreement with the ‘innocent until proven guilty’ approach some of these databases take to safety.  

Stevia extract has been shown to reduce sperm production in male rats. It has also been shown to reduce the number and birth weight of offspring in female hamsters. Finally steviol, a bi-product of metabolizing stevia in the intestine, has been shown to mutate cells.  Large amounts of steviol have also been shown to cause renal damage in animals.  

If you chose to purchase stevia in a health food store as a supplement, be aware that just because it is sold as a supplement, does not mean there are no possible side effects associated with its use. Some adverse effects reported include stomach discomfort, nausea, headache, dizziness, numbness and generalized pain. People who have allergies to daisies, marigolds, chrysanthemums, ragweed and other plants should take care when using stevia as these plants are all in the same family.  

What now? Well, it may be too soon to know if stevia is safe or not. Until more is known, it may be prudent to use it only in small amounts if at all. Pregnant women should probably not use it at all. People who have low blood pressure or problems with low blood sugar should think twice before using stevia. If you have high blood pressure or diabetes, stevia should not be used to self-medicate these conditions.