A solution: Stevia, the NutraSweet alternative

South American herb may offer health benefits

How sweet it is! The leaves of the stevia plant, native to South America and widely used in Latin America and Asia, are so intensely sweet that merely taking the cap off the bottle of powdered extract will send enough powder into the air to give you an immediate sweet taste in your mouth. What’s not to like about a plant that is 200 to 300 times sweeter than refined sugar, has no calories, is heat stable so it can be used in cooking and baking, and does not cause cavities? In short, many consider it a great alternative to synthetic sweeteners.

Conversion Chart: Sugar to Stevia
Sugar Stevia Powdered Extract Stevia Liquid Concentrate

1 cup 1 tsp 1 tsp
1 T ¼ tsp 6 to 9 drops
1 tsp pinch to 1/16 tsp 2 to 4 drops

T = tablespoon; tsp = teaspoon.
Source: The Stevia Cookbook. New York City: Avery; 1999.

"I think there should be little packets of stevia on every restaurant table in the country," says Ray Sahelian, MD, a Los Angeles physician and medical writer and author of The Stevia Cookbook (New York City: Avery; 1999). And, Sahelian asks, why isn’t stevia added to all kinds of foods and soft drinks sweetened by artificial sweeteners?

Stevia is a household word in Japan, where, by 1988, the super-sweet extract represented 41% of the market share of potentially sweet substances consumed in the country after being subjected to rigorous Japanese testing standards. In addition to its widespread use as a table sweetener, stevia is used to sweeten ice cream, bread, candies, pickles, seafood, vegetables, and soft drinks. Native tribes in South America have used the leaves of the Stevia rebaudiana bertoni plant for centuries, commonly as a treatment for diabetes.

But it is far from a household word in the United States. Here, stevia was briefly used as a sweetener in herbal teas, but by 1988, the U.S. Food and Drug Administration (FDA) issued a warning that it is not approved as a food additive, nor has it ever been added to the GRAS (generally recognized as safe) list. In fact, in 1991, the FDA listed stevia as an "unsafe food additive" based on Brazilian research, the results of which the author says were taken out of context.

Sahelian’s co-author on The Stevia Cookbook, Donna Gates, MEd, nutritional consultant, decided to take a personal stand in 1992 when the FDA refused to consider petitions to put stevia on the GRAS list. "I found it odd that the FDA refused to add stevia to the list, considering animal studies have indicated saccharin to be potentially cancer causing, yet it was being widely sold," says Gates. "In fact, the Sweet N Low package clearly mentions this concern. Why was saccharin readily available, yet stevia — a natural sweetener used for centuries in South America — was not?"

Sahelian, Gates, and numerous fellow stevia proponents theorize that the powerful companies that produce artificial sweeteners have applied unrelenting pressure on the FDA to keep stevia out of the additive market. However, NutraSweet, the company that has now become a subsidiary of Monsanto, has issued a statement denying any role in keeping stevia off the market.

Interestingly, the sweetener industry may be considering jumping onto the stevia bandwagon, according to Mindy Green, MS, AHG, director of education for the Herb Research Foundation in Boulder, CO. "I have heard rumors that Monsanto is looking into growing stevia. If and when that happens, it will be interesting to see if the rulings change," says Green.

In 1994, the passage of the Dietary Supplement Health and Education Act allowed stevia to be imported and sold as a dietary supplement despite FDA opposition; however, it still cannot be used as a food additive. Although the FDA had the power to challenge its use as a dietary supplement (and still does) by claiming there is inadequate safety information on stevia, the government would have had to bear the burden in proving this claim. At this time, the FDA has not chosen to challenge stevia. However, stevia still cannot legally be labeled as a sweetener, which some say is unfortunate given reports that it does not harm teeth, may actually help to prevent cavities, and may have antimicrobial activity.1,2

Gates and Sahelian question the FDA’s motives in the issues. "Was its ban on the import of stevia into this country and the subsequent rigid enforcement of existing rules justified by published scientific studies or are nonscientific reasons involved?"

For its part, the FDA continues to consider stevia an "unsafe food additive."

In response to a 1997 Freedom of Information Act request from a journalist, the FDA cited 19 studies it considers indicative of stevia’s questionable safety. One recognized 1968 animal study that suggests stevia has possible contraceptive effects at extremely high dosages has never been duplicated, and its author, Joseph Kuc of Purdue University, has reportedly acknowledged that his results are not necessarily applicable to human consumption. A 1999 Brazilian study showed that male rats fed high dosages of stevia had decreased plasma testosterone levels.3,4

Despite these early reports and other studies indicating nephrotoxicity and mutagenicity in animal and in vitro studies, no recent research has indicated any adverse effects from human use of stevia products. In addition, a handful of studies indicate stevia may be helpful in lowering blood sugar and others suggest its possible effectiveness as an antihypertensive.5,6 However, long-term safety data from randomized controlled trials are needed before recommendations can be made regarding use of stevia, particularly in these two patient populations.

Even if the FDA does not have all the scientific data it would like in favor of stevia, Allen Kratz, PharmD, co-editor of the Journal of the American Nutraceutical Association, based in Naples, FL, suggests that stevia had "time behind it, and time is a good teacher." Kratz is unsure why stevia has been so slow to find acceptance in the United States. "If the FDA is still unsure about it, some more investigation should be taking place. It deserves a good evaluation," he says.

References

1. Pinheiro CE, de Oliveira SS, da Silva SM. Effect of guarana and Stevia rebaudiana bertoni (leaves) extracts, and stevioside, on the fermentation and synthesis of extracellular insoluble polysaccharides of dental plaque. Rev Odontol Univ Sao Paulo 1987; 1:9-13.

2. Tomita T, Sato N, Arai T. Bactericidal activity of a fermented hot-water extract from Stevia rebaudiana bertoni towards enterohemorrhagic Escherichia coli O157:H7 and other food-borne pathogenic bacteria. Microbiol Immunol 1997; 41:1,005-1,009.

3. Mazzei Planas G, Kuc J. Contraceptive properties of Stevia rebaudiana. Science 1968; 162:1,007.

4. Melis MS. Effects of chronic administration of Stevia rebaudiana on fertility in rats. J Ethnopharmacol 1999; 67:157-161.

5. Jeppesen PB, Gregersen S, Poulsen CR. Stevioside acts directly on pancreatic beta cells to secrete insulin: Actions independent of cyclic adenosine monophosphate and adenosine triphosphate-sensitive K+-channel activity. Metabolism 2000; 49:208-214.

6. Chan P, Tomlinson B, Chen YJ, Liu. A double-blind placebo-controlled study of the effectiveness and tolerability of oral stevioside in human hypertension. Br J Clin Pharmacol 2000; 50:215-220.