Is stevia safe?
As mentioned earlier, the question of whether stevia is safe to consume largely depends on what someone means by "stevia." The U.S. Food and Drug Administration has not approved stevia leaves or "crude stevia extracts" for use as food additives. Studies on stevia in those forms raise concerns about the control of blood sugar and effects on the reproductive, cardiovascular, and renal systems, the FDA warns.
However, the FDA has allowed companies to use Rebaudioside A, an isolated chemical from stevia, as a food additive in their sweetener products. The FDA classifies these products, such as Truvia, as GRAS, but, according to the FDA, these products are not stevia. "In general, Rebaudioside A differs from stevia in that it is a highly purified product. Products marketed as 'stevia' are whole leaf Stevia or Stevia extracts of which Rebaudioside A is a component," the FDA said.
There are some health concerns surrounding the stevia plant. Stevia may cause low blood pressure, which would be of concern to some taking blood pressure medications. There is also continuing research going into certain chemicals naturally occurring in stevia that may cause genetic mutations and cancer.
"Caution is advised when using medications that may also lower blood sugar. People taking insulin or drugs for diabetes by mouth should be monitored closely by a qualified health care professional, including a pharmacist," Ulbricht said.
Stevia may also interact with anti-fungals, anti-inflammatories, anti-microbials, anti-cancer drugs, anti-virals, appetite suppressants, calcium channel blockers, cholesterol-lowering drugs, drugs that increase urination, fertility agents and other medications, Ulbricht said. People should talk with their doctor before deciding to take stevia in large amounts, she said.