Stevia – The Zero-Calorie, All-Natural Sweetener
Last reviewed by Faculty of Harvard Medical School on August 28, 2012
By Jenna B. Damareck, B.S., Dietetic Intern
Rather than asking people how many sugars they would like with their coffee or tea, we should be asking what color they want: pink, yellow, blue or green.
People who are watching their calorie or carbohydrate intake, or need to control their blood sugar levels, have several no-calorie, artificial or natural sweeteners to choose from: saccharin (Sweet N' Low), sucralose (Splenda) and aspartame (Equal). Now there's another zero-calorie, all-natural sweetener to add to the list: stevia.
Stevia comes from the Stevia rebaudiana plant. It first grew in Paraguay, a country in South America.
In 1995, the U.S. Food and Drug Administration (FDA) allowed the import of stevia leaves. But the sweetener made from the leaves could only be used as a dietary supplement. There were not enough U.S. studies showing that stevia was safe to use as an ingredient in "conventional" foods. Also, it had a bitter, unappealing aftertaste, which limited its popularity.
Then in December 2008, after many years and dollars spent in research, the FDA added stevia to the list of food additives that are "generally recognized as safe." With this designation, stevia could be added to soft drinks, sports drinks, flavored waters and any other food or beverage product.
There is good evidence from animal and human studies to suggest that foods and beverages made with stevia are safe. Only 95% pure steviol glycosides (sweet extracts from the stevia plant) are approved for use in food and beverages.
The Food and Agriculture Organization/World Health Organization Joint Expert Committee on Food Additives (JECFA) reviewed the research on stevia in 2005. The members issued temporary guidelines for how much stevia a person could safely consume. They called it the Acceptable Daily Intake (ADI).
For every kilogram of body weight, a person could safely consume up to 2 milligrams of stevia a day over a lifetime without risk. So, a 150-pound person (68 kg) could safely consume 136 milligrams (0.136 grams) of stevia per day. A 2007 study confirmed JECFA's recommendeded ADI, showing that people are likely to consume less than 2 milligrams of steviol for every kilogram of body weight per day. One packet of Truvia weighs 3.5 grams. But it isn't all stevia. It also contains rebiana and natural flavors. We don't really know how much is pure rebiana (See the Stevia Glossary.)
In 2007, the JECFA reviewed additional new research on stevia and made no changes to the guideline. Many important clinical studies are still in progress. We need to continue to monitor stevia's effects.
According to animal studies, stevia is safe to consume during pregnancy. Animals are not the same as humans, but for now it's the best evidence we have. We don't know what future research will show about this new sweetener.
There has been a great deal of buzz in the food science world regarding stevia and its safety. It appears to be a safe alternative to sugar for people, but there is no evidence yet that it can lower blood sugar.
So, don't get carried away by the excitement of a zero-calorie, all-natural sweetener. Keep in mind that anything in moderation, including real cane sugar, can be an acceptable part of a balanced diet.
Jenna B. Damareck, B.S., is a Dietetic Intern at Brigham and Women's Hospital. She received her B.S. in Dietetics and Nutrition from the University of Vermont.