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|Posted: Dec Thu 14, 2006 4:56 pm Post subject: Stevia - History & Uses - Documented
|Stevia - History & Uses - Documented
Life With Stevia: How Sweet It Is!
Nutritional and Medicinal Uses Daniel Mowrey, Ph.D.
"Life with Stevia: How Sweet It Is!" Excerpts reprinted with permission of the publisher.
Life with Stevia: How Sweet It Is! is not intended as medical advice. Its intention is solely educational. Please consult a medical or health professsional for medical advice. When one first observes the plant, nothing particular about it summons the attention, but when even a small piece of the leaf is placed in the mouth, one is amazed by its sweetness. A mere fragment of leaf is enough to sweeten the mouth for an hour. 1
Those few simple words, issued in 1899, opened one of the more remarkable chapters in the history of botanical science, and introduced the world at large to a unique and potentially revolutionary plant from Paraguay known as stevia, or "honey leaf." In South America it is primarily known as yerba dulce, but among the Guarani Indians of Paraguay, who have used the plant for centuries, it has a variety of interesting names: Caa-ehe, Azuca-caa, Kaa-he-e and Ca-a-yupe; most of these names, in one way or another, draw attention to the sweet, nectar-like flavor of the leaf. Many Guarani medicinal and nutritional plactices incorporate stevia in one way or another. The remarkable Guarni possess one of the most advanced native cultures, in terms of philosophy, nutrition and medicine, of any similar group in the world. Yet their ways are still only vaguely understood by other people. A case in point is their use of stevia.
Despite centuries of use by the Indians, it wasn't until 1899 that the plant was discovered by "civilized" man. M.S. Bertoni (quoted above) observed that the natives used the plant to sweeten their bitter drinks. Eventually, Bertoni was to be credited with the discovery of a new species; in his honor, stevia is now known as Stevia rebaudiana Bertoni.2-3
It is amazing to contemplate that most of the important herbs and spices of the world have been known, described, catalogued and used by diverse populations for several centuries; yet here is one of the most wonderful plants of world that went undeteected until the turn of this century. Some, like stevia, are less known.
Stevia as a Flavor Enhancer
There are three distinct traditions of stevia use. The first is for flavor enhancement; the second is as an herbal tea. The third is medicinal. The primary impetus for the development of stevia science was the discovery by Bertoni that the herb possessed an extraordinary sweetness. A good quality leaf is estimated to be 30 times sweeter than cane sugar, or sucrose.
The active constituents of stevia are considered by the world's leading food scientists as the "sweeteners of the future." Therefore, every new development in the area of stevia research is anxiously awaited and thoroughly analyzed when it appears. Countries in which the currently used artificial sweetners are on the brink of being banned are desperately trying to find new, safe, non-caloric sweeteners. And in other countries, firms that hold exclusive rights to currently used sweeteners are extremely fearful of the advent of new, safer sweeteners, over which they will have no control. For these firms, the emergence of a totally natural, non-patentable sweetener is the ultimate horror. Stevia, whether these firms like it or not, will one day have a dramatic impact on all countries of the world. The necessary forces simply need to be properly aligned, the raging fury of mega-monstrous companies firmly bridled by caring governments, and the supply of stevia raised to meet the enormous demand.
Steviosides and rebaudiosides are the principal constituents of diterpene glucosides with differing sugar molecules attached, as found in the leaves of the stevia plant. Extracted, they are currently being used as sweetening agents in several countries, including Japan, China, Korea, Taiwan, Israel, Uraguay, Brazil, and Paraguay. In Japan, commercialization of stevia was very rapid, beginning with the ban of artificial sweeteners during the 1960's. In 1970 the Japanese National Institute of Health began importing stevia for investigation, and by 1980 it was being used in hundreds of food products throughout the country.4
This is remarkable progress, considering that as recently as 1921 scientists were just getting around to naming the main constituent(stevioside), and the molecule wasn't even accurately described until 1931, when scientists reported it to be a white, crystalline, hygroscopic powder, approximately 300 times sweeter than cane sugar.5 And it wasn't until 1955 that the earlier work was replicated and extended.6 By 1963, the complete chemical structures of the active molecules of stevia were finally worked out.7 To jump from there to the status of a major food sweetener by the mid-1970's was a truly astounding feat, one that would have simply been impossible in the United States or Europe. Today, the Japanese, who cultivate stevia extensively in their own country, are anxious that other countries adopt the use of the plant so that they might export it. The ironic thing is that the Japanese are not as encumbered with weight problems as the rest of us; they are not, therefore, adverse to using copious amounts of plain old sugar. Yet they have access, in the form of stevia, to one of the best sugar substitutes.
"The sweetness of (stevia) satisfies my craving for sweets; also it helps keep the blood sugar balance." "When I'm drinking 2 or 3 cups of stevia tea a day, I don't experience my usual mood swings." Along these same lines, it may be that the use of whole leaf is an easier way to obtain better taste than through efforts aimed at trying to improve the taste of certain specific constituents. It is surprising, therefore, to see how much research has gone into attempting to improve the taste of individual steviosides or rebaudiosides. Since the white crystaline powder exhibits a quite persistent bitter and astringent aftertaste, cites use as a commercial sweetener often backfires. Thus, most manufacturers who use the isolated constituents of stevia usually have to combine it with other kinds of typical sugars! Since rebaudiosides taste better, methods are constantly being sought to synthetically convert steviosides to rebaudiosides. But even the rabaudiosides must be combined with other kinds of sugars to obtain necessary sweetness. Finally , in the ultimate irony, there are processes currently under development for improving the taste of stevioside by combining it in various ways with other substances obtained directly from stevia!8-9 It is the opinion of this author that most, if not all, of these convoluted attempts to improve the taste of single constituents could be satisfactorily avoided simply by using WHOLE LEAF, or whole leaf EXTRACT, the way nature intended stevia to be used. In the final analysis, pure stevioside is attractive to manufacturers mainly because of the higher profits to be achieved from using a purified, therefore patentable, material.
In this country, where use of whole leaf is the only possible mode of administration, consumers have developed some rather sophisticated applications, especially in the medicinal area (see next section). In the area of combining with other foods, one can also find some useful applications. Stevia is appropriate for use in conjunction with a variety of other herbal teas. One can mimic the South American practice of combining stevia with yerba mate, lapacho, and other native herbs, or one can experiment with stevia in altering the taste parameters of any number of traditional teas.
"We are intrigued by the honeyleaf sweetener . . . and started to use it in our breadmaking to test it for our diabetic customers. We were so pleased with the results and the improvement in the texture and softness, that we have continued to use it on a regular basis in our bread and so have all of our customers, diabetic or not."
If you purchase stevia in bulk, some can be added to beverages, sprinkled over salads or cooking vegetables and substituted for sugar in recipes without creating a problem due to the presence of the leaf itself. A little bit goes a long way.
Due to FDA regulations, pure stevioside or rebaudioside is not allowed in the United States. Even the leaf is suspect if it is labeled as a sweetener. Producers must exercise great caution in their labeling practices to avoid FDA involvement. Stevia and stevia extract are considered foods. Sweeteners are not foods, but food additives. Therefore, stevia cannot be called a sweetener. This, of course, restricts a manufacturer's ability to "get the word out" on stevia's use as a sweetening agent for teas or whatever. In practice, as long as the stevia industry poses no significant threat to the U.S. sugar or sugar substitute industries, the FDA will probably not be pressured to concern itself with what goes on with stevia labelling or use. Any perceived threat at all, however, could tip the scales the opposite way, and all forms of stevia could be banned.
To keep things low-key, remember that the sweetening effect is simply a pleasant by-product. The primary reason that stevia is combined with the other herbs is to enhance the nutritive value of the other herbs! Stevia is, after all, nutrient-rich, containing substantial amounts of protein, calcium, phosphorous and other important nutrients.10-11
Carrying the above thought a step further, there are many very ligitimate reasons for using stevia as a medicinal food. In spite of the prominence stevia has obtained as a flavor enhancer, it contains a variety of constituents besides the steviosides and rebaudiosides, including the nutrients specified above and a good deal of sterols, triterpenes, flavonoids, tannins, and an extremely rich volatile oil comprising rich proportions of aromatics, aldehyde, monoterpenes and sesquiterpenes.12 These and other, as yet unidentified constituents, probably have some impact on human physiology and may help explain some of the reported therapeutic uses of stevia.
It is probably the presence of the steviosides themselves that has produced dozens of empirical and semi-controlled reports of hypoglycemic action. Paraguayans say that stevia is helpful for hypoglycemia and diabetes because it nourishes the pancreas and thereby helps to restore normal pancreatic function13 In semi-controlled clinical reports one also encounters this action. Oviedo, et. al., reported a 35.2% fall in normal blood sugar levels 6-8 hours following the ingestion of a stevia leaf extract.14 Similar trends have been reported in humans and experimental animals by other workers.15-16 These kind of results have led physicians in Paraguay to prescribe stevia leaf tea in the treatment of diabetes;13 similarly, in Brazil, stevia tea and stevia capsules are officiallly approved for sale for the treatment of diabetes.12
However, it is important to note that stevia does not lower blood glucose levels in normal subjects. In one study, rats were fed crude extracts of stevia leaves for 56 days at a rate of 0.5 to 1.0 gram extract per day. These procedures were replicated by another team of scientists.17-18 Neither group observed a hypoglycemic action. Similar negative results have been obtained by other observers.19 Then there is research in which the findings show trends toward hypoglycemic action, but are inconclusive.20-21 In at least one of these studies, alloxan-diabetic rabbits were used. The authors felt the results supported an anti-diabetic action, but the results were transient at best.
To date, the experimental research on the effects of stevia on blood sugar levels in human patients with either diabetes or hypoglycemia is sparse. The general feeling in the scientific community is that the mild acting nature of the plant and its total lack of toxic side effects argues against the need for extensive and expensive research programs.
However, many of the anecdotes reporting a definite and significant blood sugar lowering action in diabetics, and a pronounced exhilarating effect in hypoglycemics, are sound enough to justify considerable experimental work in the area. Perhaps , when this missing piece to the puzzle is supplied, we will then have a better understanding of how stevia works - why, for example, many diabetic humans experience a profound lowering of blood sugar levels following the ingestion of several cups of stevia tea (24-32 oz.) during the course of a 24 hour period.
A good deal of experimental work has been done on the effects of stevia and stevioside on cardiovascular functioning in man and animals. Some of this work was simply looking for possible toxicity, while some was investigating possible therapeutic astion. In neither case have significant properties been found. When any action at all is observed, it is almost always a slight lowering of arterial blood pressure at low and normal doses, changing to a slight rise in arterial pressure at very high doses.22 The most curious finding is a dose dependent action on heart beat, with a slight increase appearing at lower doses, changing to a mild decrease at higher doses. In neither instance is the result remarkable, and it is extremely doubtful that humans would experience any effect at normal doses.23 The long term use of stevia would probably have a cardiotonic action, that is, would produce a mild strengthening of the heart and vascular system.
The ability of stevia to inhibit the growth and reproduction of bacteria and other infectious organisms is important in at least two respects. First, it may help explain why users of stevia-enhanced products report a lower incidence of colds and flus, and second, it has fostered the invention of a number of mouthwash and tooth paste products. Research clearly shows that
Streptococcus mutans, Pseudomonas aeruginos, Proteus vulgaris and other microbes do not thrive in the presence of the non-nutritive stevia constituents.24 This fact, combined with the naturally sweet flavor of the herb, makes it a suitable ingredient for mouth washes and for tooth pastes.25 The patent literature contains many applications for these kinds of stevia-based products. Stevia has even been shown to lower the incidence of dental caries.
Digestive Tonic Action.
In the literature of Brazil, stevia ranks high among the list of plants used for centuries by the "gauchos" of the southern plains to flavor the bitter medicinal preparations used by that nomadic culture. For example, it was widely used in their "mate." Through much experimentation, these people learned that stevia made a significant contribution to improved digestion, and that it improved overall gastrointestinal function.26 Likewise, since its introduction in China, stevia tea, made from either hot or cold water, is used as a low calorie, sweet-tasting tea, as an appetite stimulant, as a digestive aid, as an aid to weight management, and even for staying young.46
Effects on the Skin.
One of the properties of a liquid extract of stevia that has not yet been investigated experimentally is its apparent ability to help clear up skin problems. The Guarani and other people who have become familiar with stevia report that it is effective when applied to acne, seborrhea, dermatitis,eczema, etc. Placed directly in cuts and wounds, more rapid healing, without scarring, is observed. (This treatment may sting for a few seconds, but this is followed by a significant lowering of pain.) Smoother skin, softer to the touch is claimed to result from the frequent appllication of stevia poultices and extracts. Current FDA labelling regulations are forcing U.S. suppliers to label their stevia as something other than a sweetener; an appeal to its soothing action on the skin has been the most frequent alternative.
Effects on Reproduction.
An interesting pseudo-phenomenon arose at one time, and, sadly, still receives attention from time to time, in the popular press and even by serious scientists. It is sad because the whole thing is a hoax; if not that, it is at least a case of very badly mistaken identity. It seems that in 1968 a paper appeared that claimed that certain tribes of Indians in Paraguay (the Matto Grosso) used stevia tea as a contraceptive, with apparently very good results27 In subsequent experimental work, utilizing rats, these researchers found that the treatment was supposedly good for periods up to 2 months.
Subsequent work has repeatedly failed to replicate the 1968 study.28-31 Furthermore, at least one attempt to locate tribes in northeastern Paraguay that used stevia to control fertility failed to confirm the story. One effect on reproductive physiology that appears to be valid, but which is in need of further study before definitive conclusions can be drawn, is a healing effect on the processes underlying prostate disease.32 Just how important this finding is must await further research.
One of the most obvious indications of the safety of stevia is that there have never been any reports of ill effects in over 1500 years of continuous use by Paraguayans. A similar indication of safety is the observaion that despite over ten years of widespread use of stevioside as a sweetening agent in Japan, years in which literally scores of tons of stevioside were ingested, not a single report of side effects of any kind has been reported. Compare that record to the track record of aspartame, which is the number one source of consumer food complaints made to the FDA.
In spite of the record of safety, however the official laboratory tests must take place. The first official investigation of possible toxicity from stevia was performed in 1931 by Pomaret and coworkers in South America. Their tests were negative.33 They observed that stevioside passes through the human alimentary canal without being altered by digestive processes. That is, it goes out in exactly the same form that it goes in. In the decades since that observation there has raged a minor debate over this issue, but so far nobody has been able to prove Pomaret wrong. The issue is important because some of the metabolites of stevioside, as opposed to whole leaf, have been shown to be toxic (see below), and researchers have cautioned against the use of stevioside for human consumption until it is known for certain that stevioside is not metabolized in the human body. A typical statement is this from a report published in 1974:" . . . the long-term effects of ingestion of stevioside would have to be investigated carefully before it could be considered for human use as a sweetener in the United States . . . It remains to be proved that stevioside does not split to form any steviol in the human digestive tract." (italics theirs).34 This challenge is, of course, tantamount to proving a negative. Perhaps that is why the United States resists all efforts to seriously explore the possible use of stevia as a sweetener. No further progress on the issue has been made since 1974. It appears that Pomaret's observations still hold.
More elaborate safety tests were performed by the Japanese during their evaluations of stevia as a possible sweetening agent. Few substances have ever yielded such consistently negative results in toxicity trials as has stevia. Almost every toxicity test imaginable has been performed on stevia extract or stevioside at one time or another The results are always negative. No abnormalities in weight change, food intake, cell or membrane characteristics, enzyme and substrate utilization, or chromosome characteristics. No cancer,no birth defects, no acute and no chronic untoward effects. Nothing.35-39
The only related effect ever observed was the inhibition cell respiration (oxidative phosphorylation) in certain isolated cell components, but never in whole cells. The only observable result of this action, even after prolonged observation, was a reduction in toxicity due to a substance known as atractylignin, a poison that attacks cells of the liver. This result suggests that stevia could be used as an antidote to rare cases of poisoning by that chemical. The overall result of this action of stevia, then, turns out to be positive.40
An example of a good toxicology trial was one performed in 1985 by Yamada and coworkers. They administered stevioside and rebaudioside A to rats for two years at the rate of 0.3 - 1% of their diet. The animals were then sacrificed, and the researchers conducted bio-chemical, anatomic, pathological and carcinogenic tests on 41 organs following autopsy. In addition they performed ongoing hematologic and urine tests on the same animals. Each of the animals was matched to a control animal that experienced exactly the same treatment except for the stevia. In the end, the symptoms and alterations noted by the research staff did not vary at all between the groups, and no dose-response effects were noted, even at the highest dose (1%), which is equivalent to 125 times the average daily dose of sweeteners that a normal human would require.41
Similar batteries of tests carried out by the National Ministry of Health and Welfare in Japan also failed to find any form of toxicity whatsoever.42 But there is a fly in the ointment, so to speak. As mentioned earlier, there has been a fear that metabolites of stevioside and rebaudioside A might be doing serious harm to the body. As one author put it: "In spite of the fact that acute oral administration of large doses of stevioside and/or Stevia rebaudiana extracts and long-term studies with feeding either of these materials to laboratory animals have shown them to be virtually devoid of toxic effects, one must consider the limited data available on metabolites (italics mine) of the major sweet principles of this plant."43 Now this comment was made in full knowledge of the fact that stevioside and the other glycosides of stevia are remarkable for their chemical stability; that is, due to their peculiar chemical or molecular shape, stevia glycosides are extremely resistant to acid and enzymatic degradation. They simply cannot be broken down into their metabolites under normal gastric conditions. Gastric acids and enzymes, as found in humans, are incapable of degrading these extremely stable molecules. This is in line with Pomaret's study that found that steviosides passed unchanged through the human gastrointestinal tract. Apparently the situation is different in the rat. In 1980 R.E. Wingard and associates reported that stevioside and rebaudioside A were both degraded to steviol by rat intestinal microflora in a test tube.44 Steviol is one of the nasty metabolites that could, maybe, perhaps, do humans serious harm.
Wingard incubated the stevioside for 2-4 days in a specially prepared solution containing the contents of the rat cecum. Under these conditions, conversion was almost 100%. However, as Kinghorn and Soejarto have pointed out, there are just two things wrong with extrapolating these results to humans.45 First, humans do not have a cecum, as does the rat; therefore, a
critical step in the conversion process has no equivalent physical location in which to occur. And second, there is no good reason to believe that the microflora of the human intestinal tract contains the same microorganisms as does the rat cecum.
One would think, in light of the seriousness of the theoretical charge posed by Wingard, that scientists would be clamoring to settle the issue through appropriate experimental measures. Not so. It's as if no one really takes the threat seriously. After all, it is unlikely that some kind of observable consequence of steviol (the metabolite) intoxication would not have been reported during decades of stevia use if, in fact, a real problem existed. Since no reports have been forthcoming, we can daringly conclude (apparently along with the rest of the scientific community) that humans are different from rats.
Conclusions from Safety Data.
One might reasonably ask, based on these toxicological data, why efforts to make stevia the sugar substitute of choice in the United States and Europe have failed so miserably, and why, in fact, individuals who have attempted to produce high quality stevia liquid extracts in the United States have been threatened with prosecution. Here we have a plant, totally innocuous, posing no threat to human life and health, holding out in fact great hope for the production of a non-caloric sweetener with health benefits, that is being systematically suppressed.
Perhaps, in view of the numerous health benefits discussed in this booklet (and the dozens of anecdotal uses not discussed, such as the ability to reduce the craving for sweets and fatty foods, and as a stop-smoking and/or stop drinking aide, the time has arrived for consumers to begin insisting on their right to freely use this fine, delectable plant.
From The Jungles To You
The Guarani Indian Tribes first came to the attention of Europeans sometime in the 1600's and were the subject of an intense missionary effort in the early 1700's. They were found to be a beautiful, ethical, highly skilled, very intelligent and gifted culture. Today, pure-blooded Guarani are declining in number, but much of their civilization has been preserved in one form or another. Thus it is that every once in a while, some one will be lucky enough to learn one or two of the secrets of the Guarani; even more rarely, such a lucky person will share it with the rest of us. As a result, we are just barely beginning to see some of the Guarani medical remedies reach the shores of North America.
One of the most promising of Guarani medicinal substances is, of course, stevia. It is known as "sweet leaf," or "honey leaf." This suggests the primary use of the plant in folklore use. Long before the country was colonized by the Spaniards in the sixteenth century, stevia was being employed to make food and drink palatable. Medicinally, the plant was used to treat diabetic and hypoglycemic conditions, and externally for keeping skin and hair youthful and healthy.
Today, in homes and some clinics in rural Paraguay, stevia in high doses is given in tea form as a remedy for high blood sugar levels. The tonic, stomach-soothing, digestive, hypotensive and immune-stimulating actions of stevia are well known.
It is interesting to see where stevia occurs in the traditional folk remedies of the native Guarani. Numerous are the folk medicines that contain stevia, either as a flavor enhancer or for its own medicinal properties.
Let us hope that the day will soon come when simple, time-honored, health traditions with extraordinary potential for improving the lot of mankind, can be freely and openly offered to the world without interference from self-serving individuals, agencies, organizations and corporations which profit from the suppression of such fabulous, compelling and ultimately superior natural remedies.
1. Bertoni, M.S. "El Caa-ehe (Eupatorium rebaudianum, species nova)". Rev. Agr., Ascunion 1: 35-37, 1899.
2. Bertoni, M.S. "Le Kaa He-e. Sa nature et ses properietes." Ancient. Paraguayos, 1(5), 1-14, 1905.
3. Bertoni, M.S. "Caa-hee (stevia rebaudiana Bertoni)." Bol. Est. Agr. Puerto Bertoni Paraguay, V(2), 54, 1911.
4. Fujita, H. & Edahiro, T. "Safety and utilization of stevia sweetener." The Food Industry. 22(22), 1-8, 1979.
5. Bridel, M. & Lavielle, R. "Sur le principe sucre des feuilles de kaa-he-e (stevia rebaundiana B)." Compt. Rend., Acad. Sci., Parts 192, 1123-1125, 1931.
6. Wood, Jr., H.B., et. al., "Stevioside. I. The structure of the glucose moieties." J. Org. Chem. Washington, 20, 875-883, 1955.
7. Mosettig, E., et.al., "The absolute configuration of steviol and isosteviol." J. Am. Chem. Soc., 85(15), 2305-2309, 1963.
8. Morita, T., MOrita, E. & Fujita, I. Jpn Kokai Tokkyo Koho, 77,57,366; Chem Abstr., 87, 132564t, 1977.
9. Morita, T., Fujita, M. & Morita, E. Jpn. Kokai Tokkyo Koho, 77,105,260; thru Chem Abstr. 88, 49255t, 1978.
10. Viana, A.M. & Metivier, J. "Changes in the levels of total soluble proteins and sugars during leaf ontogeny in stevia rebaudiana Bert." Annals of Botany, 45, 469-474, 1980.
11. "Hierbas Medicinales, Caa Jhee." Bulletin, Centro de Promocion de las Exportaciones, Ministerio de Industria Y Comercio, Paraguay.
12. Reviewed by Kinghorn, A.D. & Soejarto, D.D. "Current status of stevioside as a sweetening agent for human use." Economic and Medicinal Plant Research, Volume 1, Wagner, H., Hikino, H. and Farnsworth, N.R. (eds.) Academic Press, New York, 1985, pp. 1-51.
13. Soejarto, D.D., et.al., Econ. Bot., 37, 74, 1983.
14. Oviedo, C.A., et.al., "Accion hipoglicemiante de la stevia rebaudiana Bertoni (Kaa-he-e)." Excerpta Medica, 208, 92-93, 1971. (International Congress Series).
15. Alvares, M., et.al., Abstract Pap., Semin. Bras. Stevia Rebaudiana Bertoni 1st, 1981, p. XIII.I.
16. Suzuki, H., et.al., "Influence of oral administration of stevioside on levels of blood glucose and liver glycogen of intact rats." Nippon Nopei Kagaku Kaishi, Tokyo, 51(3), 171-173, 1977.
17. Akashi, H. & Yokoyama, Y. "Dried-leaf extracts of stevia. Toxicological test." Shokihin Kokyo, Tokyo, 18(20), 34-43, 1975.
18. Lee, C.K., et.al., Hanguk, Sikp'um Kwahakhoe Chi, 11, 224-6, 1979. 19. Usami, M., et.al., Horm. Metab. Res., 12,705, 1980.
20. Piheiro, C.E. & Gasparini, O.T. Abstr. Pap., Semin. Bras. Stevia rebaudiana, 1st, 1981, pp. XV.I-XV.IV.
21. Boeckh, E.M.A., "Stevia rebaudiana (Bert.) Bertoni: clinical evaluation of its acute action on cardio-circulatory, metabolic and electrolitic parameters in 60 healthy individuals." Third Brazilian Seminar on Stevia Rebaudiana (Bert.) Bertoni, (Summaries), Angelucci, E. (Coordinator), July, 1986, pp. 22-23.
22. Machado, E., Chagas, A.M. & Reis, D.S. "Stevia rebaudiana (Bert.) Bertoni in the arterial presure of the dog." Third Brazilian Seminar on Stevia Rebaudiana (Bert.) Bertoni, (Summaries), Angelucci, E. (Coordinator), July 1986, p. 11.
23. Boeckh, E.M.A. op.cit.
24. Yabu, M., et.al., "Studies on stevioside, natural, sweetener." Hiroshima Daigaku Shigaku Tasshi, 9(1), 12-17, 1977.
25. Berry, C.W. & Henry, C.A. J. Dental Res., 690,430,1981.
26. Alvarez, M. "Stevia rebaudiana (Bert.) Bertoni: Toxicological aspects." Third Brazilian Seminar on Stevia Rebaudiana (Bert.) Bertoni, (Summaries), Angelucci, E. (Coordinator), July 1986, p. 4-7.
27. Planas, G.M. & Kuc,J. "Contraceptive properties of stevia rebaudiana." Science, Washington, 162, 1007, 1968.
28. Farnsworth, N.R. "Current status of sugar substitutes." Am. Perfum. Cosmet., 88(7), 27-35. 1973.
29. Akashi and Yokoyama, 1975, op.cit.
30. Fujita and Edahiro, 1979, op.cit.
31. Silva, A.R., Saldanha, C.M., Boelter, R. & Chagas, A.M. "Fertility of rats: Aqueous extract of stevia rebaudiana (Bert.) Bertoni and stevioside, " Third Brazilian Seminar on Stevia Rebaudiana (Bert.) Bertoni, (Summaries), Angelucci, E. (Coordinator), July 1986, p. 19.
32. Oliveira-Filho, R.M. Valle, L.B.S. Minetti, C.A.S.A. & Uchara, O.A. "Evaluation of the effects of raw stevia rebaudiana extract in the endocrinous sphere; study on rats." Third Brazilian Seminar on Stevia Rebaudiana (Bert.) Bertoni, (Summaries), Angelucci, E. (Coordinator), July 1986, p. 20.
33. Pomaret, M. Lavieille, R. "Le principe & saveur sucree du Kaa-he-e (stevia rebaundiana bertoni), IV. Quelques proprietes physiologiques du stevioside." Bull, Soc. Chim, Biol., 13, 1248-1252, 1931.
34. Hodge, J.e. & Inglett, G.E. "Structural aspects of glycosidic sweeteners containing (1'2)-linked disaccharides." In Inglett, G.E. (ed.) Symposium Sweeteners. The Avi Publishing Company, Inc. Conn., 1974, pp. 216-234.
35. Mitsuhashi, H., et.al., Yakugaku Zasshi, 95, 127; and 95, 1501.
36. Akashi, H. & Yokoyama, Y. "Dried leaf extracts of stevia. Toxicological test." Shokuhin Kogyo, 18(20), 34-43, 1975.
37. Fujita, H. & Edahiro, T. Shokuhin Kogyo, 22(20), 66, 1979, 22 (22), 65, 1979.
39. Medon, P.J., et.al., Fed. Proc., Fed. Am. Soc. Exp. Biol., 41, 1568, 1982.
40. Ishit,p. 9. E.I. & Bracht, A. "Stevioside inhibits the toxic action of actractiloside on the liver,," Third Brazilian Seminar on Stevia Rebaudiana (Bert.) Bertoni, (Summaries), Angelucci, E. (Coordinator), July 1986, 41. Yamada, et.al., Shokuhin Eisegaku Zasshi, 26(2), 169-183, 1985.
42. Food Chemistry Division, Environmental Health Bureau, Ministry of Health and Welfare. "Toxicological effect of a sugar alternative, stevia products." January 1981.
43. Kinghorn & Soejarto, 1985, op.cit.
45. Wingard, R.E. (reviewed in Kinghorn (Sejarto, 1985)
46. Kinghorn,, D.a. & Soejarto, D.D. "Stevioside," in Economic and Medical Plant Research, Vol. 7, Academic Press, 1991, pp. 157-171.
ABOUT THE AUTHOR
Dr. Mowry is known primarily for his efforts to bring scientific data about herbal medicine to the attention of the American public. Toward this end he has published the books entitled the Scientific Validation of Herbal Medicine, and Guaranteed Potency Herbs: Next Generation Herbal Medicine, which have become standard texts in the field. Dr. Mowry is Director of the Mountainwest Institute of Herbal Sciences, in Salt Lake City, Utah. ©1992 by Daniel B. Mowry