A plant native to South America and Central America, stevia (Stevia rebaudiana) produces sweet leaves that have long been harvested to flavor foods and beverages. In recent years, a stevia extract called rebaudioside A has become increasingly popular as a natural sugar substitute.
Stevia as a Sweetener
With zero calories, stevia extract looks like sugar but is exponentially sweeter. Now found in foods like soft drinks, candy, and pre-packaged baked goods, stevia extract is also sold as a tabletop sweetener. Suggested uses include sweetening coffee and tea, as well as sprinkling onto cereal, oatmeal, fruit, and yogurt.
Side Effects and Safety of Stevia
In 2008, after several major food companies (including Coca-Cola and PepsiCo) performed scientific reviews that deemed stevia extract to be "generally recognized as safe," the U.S. Food and Drug Administration approved its use as a food additive. Prior to the FDA approval, stevia could only be marketed as a dietary supplement and was commonly sold as a liquid extract in natural foods stores.
Some health advocates condemn the FDA's approval of stevia extract, citing research showing that stevia consumption may cause DNA damage in rats. It's important to note that this research tested the effects of stevioside (another compound found in stevia) and not rebaudioside A. To date, there's no compelling evidence that rebaudioside A is unsafe for human consumption.
Use for Diabetes
Since it contains no calories or carbohydrates and does not cause a spike in blood sugar levels, stevia is considered safe for people with diabetes. But claims that all forms of stevia extract can actually boost health in diabetes patients may be unfounded. While tests on animals have determined that stevioside may help lower blood pressure and regulate blood sugar in diabetics, a 2008 study concluded that rebaudioside A failed to provide similar benefits.
When Should You Use Stevia?
Stevia-extract-sweetened foods and beverages are most likely a healthier option than similar items made with artificial sweeteners such as aspartame. But for optimal health, it's best to cut back on processed foods and choose naturally sweet alternatives such as fruit in its fresh or dried form.
If you're seeking a new natural sweetener, you should also consider erythritol (a nearly calorie-free sugar alcohol extracted from plants).
Dyrskog SE, Jeppesen PB, Chen J, Christensen LP, Hermansen K. " The diterpene glycoside, rebaudioside A, does not improve glycemic control or affect blood pressure after eight weeks treatment in the Goto-Kakizaki rat." The review of Diabetic Studies 2005 2(2):84-91.
Nunes AP, Ferreira-Machado SC, Nunes RM, Dantas FJ, De Mattos JC, Caldeira-de-Araújo A. "Analysis of genotoxic potentiality of stevioside by comet assay." Food and Chemical Toxicology 2007 45(4):662-6.