‘Stevia’, the future ?
Where doubtful conclusions could be drawn for aspartame and other sweeteners, Stevia rebaudiana is a completely new thing.
Stevia, a natural sugar substitute, is widely used for several years in South America and Japan. In its extract-form it can be used in everything, from candy to chocolate and even in sweet sauces like Spring roll sauce.
Stevia consists out of so called ‘steviolglycosides’, which are the sweeteners. There are eight steviolglycosides in the leaves of the plant, the most common are stevioside and Rebaudioside A. (see figure below) Each of these steviolglycosides consist out of a central steviol-molecule and sugar-units around it. [1]
Structure of Stevioside
Structure of Rebaudioside A
These molecules are too large for absorption in our intestines. As the sugar-units are attached by beta-glycosidic bonds to the central steviol core, they can’t be split from the molecule. The sweeteners travel to the colon unchanged and are demolished by the intestinal flora to steviol and sugar-unit. The sugar-units are then incinerated by the bacteria itself.[1]
It has numerous advantages over sugar. It provides no calories, is 100% natural and does not cause caries. Yet it was banned in the European Union until 2010 the Food Safety Authority EFSA (European Food Safety Authority) Stevia declared it safe.
Now the question arises: ‘Why did it take so long to get approved in Europe, considering it has been used for decades in other countries?’
According to Jan Geuns the answer is loud and clear: lobbyists. [1] Big companies who have no interest in changing their production flow and see their shares drop to the bottom.
Another strange thing: in the future, when the steviolglycosides are used in product, they should be indicated with an E-number, for additives[1]. Very strange considering the other additives are chemical and Stevia is natural. It is considered as a so called ‘Novel food’ or ‘Nieuw voedsel’[1]. But isn’t new at all!
Furthermore scientifics all over the world have concluded that Stevia is perfectly save.
A summary of findings:
– The letal dose is very high (15-20 g/kg bw/d)
– It’s not carcinogenic, there’s even demonstrated that it reduces the development of skin cancer induced with chemicals [2,3,4]
– The absorption of Rebaudioside A and Stevioside are studied in human volunteers. They aren’t absorbed in the intestines and arrive in the colon unchanged. There they are split by the bacteria and steviol is formed. A part of the Steviol molecule may be absorbed in the colon and transferred to the lever and converted to steviolgluceronides which is excreted in the kidneys. No accumulation of Steviol was found in the body! [5]
– Etc.
After all, Stevia got approved in 2010. But now it is only waiting for an official authorization for the use in foods. Those are expected in late 2011.
Freija Abé
References:
[1] Geuns J., Stevia en steviolglycosiden: de naakte waarheid over Stevia. 2010, Euprint
[2] Toyoda et al, Assessment of the carcinogenity of Stevioside in F344 rats. Foods and Chemical Toxicology, 1997, 35;597-603.
[3]Yasuwaka et al, Inhibitory effect of stevioside on tumor promotion by 12-O-tetradecanoylphorbol-13-acetaat in two-stage carcinogenesis in mouse skin. Biological & Pharmalogical Bulletin, 2002, 25; 1488-1490.
[4] Takasaki et al, Cancer preventive agents. Part 8: Chemopreventives effects of stevioside an related compounds. Bioorganic & Medicinal Chemistry, 2008.
[5] Guens et al, The safety of Stevioside used as a sweetener. p 85 – 127. In: Guens et al, Proceedings of the first symposium ‘Safety of Stevioside’ Leuven, April 16, 2004. Euprint Ed. ISBN 9074253024.
Real food is non-processed food, straight from the farm. 
christelhouben said,
February 5, 2011 @ 5:40 pm
I think Stevia could be a good alternative substitute instead of aspartame because the sweeteners of Stevia, are 300 times sweeter than sugar and contain no calories [1]. So these are great advantages compared to sugar. It is also sweeter than aspartame, because aspartame is 200 times sweeter than sugar [2].
The leaves contain 8 glycosides, as Freija told. These are stevioside, steviolbioside, rebaudiosides (A,B,C,D,E) and dulcoside A [3]. The sweeteners of Stevia are especially stevioside and rebaudioside A. When looking at the toxicological studies they shown that in rats, stevioside and rebaudioside A will be degraded by the gut flora to steviol. Stevioside will degrade into steviol for 100% and rebaudioside for 65% [3]. Meanwhile stevioside will not be absorbed as Freija also told, however steviol will be absorbed. There has also been a study of Wingard et al. shown that stevioside will also degrade in man [3]. Because steviol seems to be mutagenic, it could be a problem. This is shown by a study with S. typhimurium TM677. But in a mouse micronucleus test the test on the mutagenicity of steviol was negative. So there is need to do some additional mutagenicity studies in vivo.
Checking the acute toxicity of stevioside and steviol it seems to have a very low oral toxicity to mice, hamsters and rats [3].
When looking at the carcinogenic studies in rats, Toyoda K. et al. shown there was no quantification of impurities in stevioside but the male rate developed interstitial cells tumours in the testis. So the major concern is on the male reproductive system, such as reduced spermatogenesis, etc. [3].
Even when they gave extracts of S. rebaudiana in the drinking water of rats, they shown infertility for up to two months.
There were also done some studies where stevioside didn’t shown any malformations in foetuses or has no effect on the fertility. There were also no teratogenic effects. But when steviol was given (500-1000 mg/kg bw/day), toxicity was induced [3].
Thus it seems that not stevioside, but the metabolite steviol, is toxic. However stevioside can cause some problems in the male reproductive system. That is why the Committee of Europe still has doubts about this sweetener [3].
Because the article of the Committee of Europe is obsolete, I searched for another article. There is shown that when stevioside is used in an ADI quantity of 16,6 mg/kg bw/day for a person of 60 kg, this sweetener is well-tolerated [4]. For steviol, the metabolite of stevioside and rebaudioside A, this is an ADI of 5,5 mg/kg bw/day [4].
To conclude Stevia has some advantages but also some disadvantages. That is way there is done a lot of research on Stevia. But there result are sometimes contradictable, that is way in the future I think there has to be done more research on human.
References:
[1] Eustas, European Stevia Association, 2006, http://www.eustas.org/engl/index_engl.html, consulted on 05/02/2011
[2] Debra Manzella et al., Artificial sweetener reference chart, About.com Guide, 2007, http://diabetes.about.com/od/nutrition/a/sugarsubchart.htm, 05/02/2011
[3] European commission, Scientific committee on food, 1999, http://ec.europa.eu/food/fs/sc/scf/out34_en.pdf, consulted on 05/02/2011
[4] EFSA, European Food Safety Authority, Scientific Opinion on the safety of steviol glycosides for the proposed uses as a food additive, EFSA Journal 2010;8(4):1537, http://www.efsa.europa.eu/en/scdocs/doc/1537.pdf, consulted on 05/02/2011
Jo Lefebure said,
February 16, 2011 @ 11:05 am
It’s great to see that stevia has finally been approved by EFSA, I think it’s a major step forward for the European stevia fans. Won’t be long until we can enjoy stevia products here in Belgium as well. I think it’ll gain a lot of popularity once the first products hit the shelves.
If you want to have more info on stevia, I recommend you visit my site (soon to be in Dutch as well).
abefreija said,
February 17, 2011 @ 5:31 pm
Recent toxicological studies showed no adverse effects of steviol.
According to studies by Guens et al (2004, 2006 and 2007) and Simonetti et al (2004) on human volunteers, steviol was absorbed in the colon but was not found in the blood. This implies that all steviol was converted to steviol gluceroniden (which is excreted through the kidneys) and that therefore no accumulation of steviol occurs in the body. In addition, specific tests were also done on the toxicity of steviol in animals and humans, showing that it is perfectly safe (Sekihashi, 2002).
So there shouldn’t be any more reasons for stevia to be forbidden.
As I already metioned before: Stevia will has to be declared as an additive, i.e. as a ‘sweetener’, with E number E960.
In the category of “sweeteners” it is striking that all, except thaumatin, are artificial sweeteners. They are not naturally acquired, and Stevia is though. Consistenly, Tagatose and sugar should also be given an E number considering Geuns, since they also are ‘sweeteners’ AND natural.
Furthermore, the effects of excessive sugar consumption in our society are visible. 23% of women and 37% of men suffers overweight. And it’s this ‘overweight’ that causes the well-known disease type II diabetes mellutis. Even the youth is not spared. An examination of the VUB (Vrije Universiteit Brussel) show that obesity has tripled in the past 30 years. In Flanders 12 to 15% of the young people are obese. (De Smet, 2010) Can there be stated that sugar is completely safe then, wonders Professor Jan Geuns?
The key question is perhaps: how will consumers react to this declaration of Stevia? An additive often has a negative image, and fraud is a real problem.
What do you think about this?
References
Geuns, J.M.C. et al. (2004). Safety of Stevioside used as a sweetener. “Proceedings of the first symposium on the safety of Stevioside”, in Geuns J.M.C. “Proceedings of the first symposium on the safety of Stevioside”. KULeuven (Heverlee): Euprint ed.
Geuns, J.M.C et al. (2006). Identification of Steviol Gluceronide in human urine. J. Agric. Food Chem., 54, 2794-2798.
Geuns, J.M.C. et al. (2007). Stevioside metabolism by human volunteers. Experimental Biology and Medicine, 232(1), 164-173.
Sekihashi, K. et al. (2002). Genotoxicity studies of Stevia extracts and steviol by the comet assay. J. Toxicol. SC., supplement I, 1-8.
Simonetti, P. et al. (2004). Bioavailability of Stevioside from Stevia rebaudiana in human volunteers: preliminary report p 51-62, in Guens, J.M.C. “Proceedings of the first symposium on the safety of Stevioside”. KULeuven(Heverlee): Euprint editions.
De Smet, F. (2010, januari 5). Jongeren worden dike reuzen. Retrieved from: http://www.nieuwsblad.be/article/detail.aspx?articleid=G9M2KEM3S
abefreija said,
February 17, 2011 @ 6:03 pm
I think Zerose could sure has a future in a kinds of food stuff but maybe not in beverages. As Koen already said, polyols can be very laxative and considering the current daily consumption of sodas, namely 75% of the young males (15-18 years) drinkat least 1 can of soft drink a day in Belgium (Coenen, 2006) there could be a lot of digestive problems.
Furthermore it’s sweetness intensity is only 60-70% that of sucrose, which means more Zerose should be added to get the same sweetness.
References:
Coenen, I. (2008). Resultaten van de eerste Belgische voedselconsumptiepeiling – Het voedingspatroon van de Belgen wijkt sterk af van de aanbevelingen. Nutrinews, 2, 18-24.
christelhouben said,
February 19, 2011 @ 2:34 pm
What I think is, if they are some disadvantages, the benefits are less important. Because only 1 disadvantage can be too dominant. And if this disadvantage is that the product has laxative effect, I wouldn’t use it.
Because I think a lot of people wouldn’t be glad if they should know it has a laxative effect. But on the other hand, a lot of candy has a laxative effect when you use it in excessive amounts. It just has to be mentioned on the outside of the candy bag.
So to me it seems that this is true for a lot of additives, when you don’t exceed excessive amounts there won’t be a problem.
christelhouben said,
February 19, 2011 @ 3:14 pm
As Freija told there are done a lot of research until now on stevia and the metabolites. So it seems that it wouldn’t take long before it will be launched on the food market in Europe. As also is stated by an article in ‘Het belang van Limburg’ on Monday the seventh of February of the year 2011. In this article they also write that steviol glycosides are healthy and as Freija already told the molecules are too big to be absorbed by the intestine. They will also lead to less obesity because they don’t contain calories.
It is already been told in other reactions or replies, but I wanted to confirm that is was also in a newspaper, so it means that it is a very important subject because even in the media there is paid attention to this sweetener.
Because of all this attention and the advantages of stevia, I think consumers will be glad with this declaration. Especially the people who need it the most, diabetic people.
Reference:
Dries Stevens et al., Koken met STEVIA, Het belang van Limburg, 07/02/2011, p.14