Stevia is a plant related to the chrysanthemum that is native to South America. The extract from the stevia plant is used as a natural alternative to sucrose, or table sugar. Proponents of stevia claim that it can actually benefit your health. Some studies indicate that consuming too much stevia can harm testosterone levels in male rats, but there's no evidence to show that it has the same effect in humans.
Stevia may be beneficial for some consumers because it does not contain sugar. Instead, it has a natural substance called glycosides that tastes 300 times sweeter than sucrose, or table sugar, according to Renee Loux Underkoffler, author of "Living Cuisine." Diabetics can enjoy foods sweetened with stevia without experiencing a spike in blood sugar. Stevia does not harm the teeth or cause cavities. Additionally, stevia might help lower blood pressure, as well as help combat heart damage associated with high blood pressure, explains the NYU Langone Medical Center.
Effects in Animal Studies
Studies such as a 2008 study that appeared in "Revista Peruana de Biología" demonstrate that stevia may affect the plasma testosterone level in lab rats. Scientists believe that the glycosides, or the sweetening substance in stevia, may affect androgen receptors, causing a drop in fertility, according to a 1999 study in the "Journal of Ethnopharmacology:" As of publication time, there is no scientific evidence that demonstrates conclusively that stevia can affect the testosterone levels of human males, however.
Effects in Human Studies
As of March 2014, no study has thoroughly investigated the role of stevia in regulating testosterone levels in humans. However, one study, published in the "Journal of Chiropractic Medicine" in 2013 found that taking a dietary supplement, made up of stevia and several other herbs, had no negative effects on testosterone levels, and people who received the supplement and followed a weight loss diet actually had slightly higher testosterone after the study concluded. This does not mean that stevia increases testosterone levels, but it does illustrate that it doesn't seem to have a negative effect, when consumed as part of a healthy lifestyle. The NYU Langone Medical Center also notes that normal consumption of stevia should not negatively affect fertility.
Stevia tastes like sucrose but it has a slight aftertaste that is reminiscent of licorice. Use stevia wherever you would use sugar, such as to sweeten coffee. Cooking with stevia may be more challenging because it reacts differently in foods than sucrose, but you can use it to boost the sweetness of foods such as a simple syrup or to sweeten fruit. If you wish to cook with stevia, keep in mind that it is much sweeter than sugar. Several stevia cookbooks are available if you do not wish to experiment on your own.