Stevia Toxicity

If you want to use a low-calorie replacement for sugar you have a several options, including aspartame, saccharin and neotame. One of the more recent sweeteners available to consumers is stevia. At times, non-sucrose sweeteners have been labeled as dangerous and possibly toxic. Stevia was no exception to this trend when it first became available as a dietary supplement, but it has since been approved as safe by the U.S. Food and Drug Administration, or FDA.

FDA Ban

According to the University of Nebraska, the FDA banned stevia for sale in the United States in 1991 because there was insufficient information to confirm it was safe for humans to consume in large quantities. After a more extensive review of the available research, the FDA approved stevia for sale as a dietary supplement in 1995, demonstrating a gradual acceptance of stevia as a nontoxic substance.

Sweetener Approval

In December 2008, the FDA issued approval for three companies to use stevia as a sweetener in soft drinks. The approval granted stevia sweeteners a generally recognized as safe, or GRAS, status with the FDA. However, the approval from the FDA did not cover all stevia sweeteners. There are two main types of sweeteners derived from stevia plants: rebaudioside A and stevioside. The American Dietetic Association states that only highly purified rebaudioside A sweeteners meet the FDA's stringent standards.

Mutagenic Properties

A majority of studies have not shown any toxic or carcinogenic effects associated with stevia sweeteners. However, researchers at the University of California did find that some stevia extracts have shown dose-dependent positive results in mutagenicity tests. The 2008 work of the UCLA researchers was included as a part of the FDA's GRAS review for stevia sweeteners. They were not able to specifically identify the stevia extract that caused the mutations in laboratory animals, and recommended further testing in this area as a part of their report.

Safe Dosage

The World Health Organization's Joint Expert Committee on Food Additives completed a significant review of stevia sweeteners in 2008, and concluded that you can consume between 0 mg and 4 mg per kg of body weight safely per day. This is equivalent to 272 mg per day for a 150-lb. person at the maximum dose. The New York University Langone Medical Center states that some clinical trials of stevia have had patients consume between 750 mg and 1,500 mg of stevia per day without significant side effects.