This year, a few noncaloric sweeteners made from an extract of the Stevia rebaudiana plant arrived on grocery-store shelves. The stevia plant has a long history of use as a sweetener in South America. These new sweeteners—sold under brand names like Truvia and PureVia—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 regarded as safe (GRAS) ingredient.
The FDA affirmed the GRAS status, but did not change the previous ruling on stevia. “Reb A is different than whole-leaf stevia or [other] stevia extracts, which can only be sold as dietary supplements,” says FDA spokesperson Michael Herndon. “Nobody has provided the FDA with evidence that whole-leaf stevia is safe.”
The Center for Science in the Public Interest (CSPI), a consumer advocacy group, believes that 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.”
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).