A. Stevia has been touted as a "natural" sweetener and an alternative to sugar, but is it safe for us? Though it seems this non-caloric sweetener just made its name recently, the stevia plant has a long history of use as a sweetener in South America. These newer stevia sweeteners—sold under brand names like Truvia, Stevia in the Raw or OnlySweet, and in blends with sugar, such as PureVia or Born Sweet Zing (at 8 to 10 calories per teaspoon)—include a highly purified extract of stevia called Rebaudioside A (a.k.a. Rebiana or Reb A). Reb A is 200 times sweeter than sugar and does not raise blood sugar.
Until December 2008, stevia and its derivatives could be sold in the U.S. only as dietary supplements, due to safety concerns. In the 1980s, animal studies linked stevia with adverse effects on fertility and reproductive development and possible genetic mutations. But in 2008, the makers of Truvia and PureVia submitted research to the Food and Drug Administration regarding Reb A's safety and petitioned for it to become a Generally Recognized as Safe (GRAS) ingredient.
The FDA affirmed, and still maintains, the GRAS status only for highly purified stevia extracts (Rebaudioside A, or Reb A). Whole stevia leafs, including products containing "crude stevia extract" or "whole leaf stevia," are not classified as GRAS because data is lacking on their effects on the cardiovascular, urinary and reproductive systems.
However, some consumer advocacy groups, like The Center for Science in the Public Interest (CSPI), criticize the quality of the studies (which are often done by the manufacturers themselves) and think the Reb A's GRAS status was granted prematurely. "In the past, FDA protocol required repeated testing in two separate animal species prior to approval, but in this case it didn't," says David Schardt, nutrition expert with CSPI. "We are not warning people to avoid Reb A, but the public should be aware that the FDA did not follow all the usual safeguards."
Despite being "natural," sugar substitutes like Stevia that earn the GRAS status usually don't have as much safety data as approved additives, meaning it's worth using Stevia sparingly—the daily acceptable dietary intake, or ADI, for Stevia is 9 packets.
Bottom Line: The FDA considers Reb A a safe sugar substitute, but has not approved other forms of stevia. If you want to use stevia, we suggest sticking with Reb A (look for it on the ingredient label), and using it sparingly.