Doctor's Note

For more on alternative sweeteners, check out these videos:
Erythritol May Be a Sweet Antioxidant
Aspartame-Induced Fibromyalgia
Aspartame and the Brain
Neurobiology of Artificial Sweeteners
How Diet Soda Could Make Us Gain Weight

And check out the other “HHH” videos (Harmful, Harmless, or Helpful?) – listed below the post.

Also, check out my associated blog posts: Vitamin B12: how much, how often?Kiwi Fruit for Irritable Bowel SyndromeIs Caffeinated Tea Really Dehydrating?Soy milk: shake it up!; and Is There a Safe, Low-Calorie Sweetener?

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  • Michael Greger M.D.

    Please feel free to post any ask-the-doctor type questions here in the comments section and I’d be happy to try to answer them. And check out the other “HHH” videos (Harmful, Harmless, or Helpful?). Also, there are over a thousand subjects covered in the rest of my videos–please feel free to explore them as well!

  • MelanieP

    1. Have there been any other studies other than the one mentioned in the video? To be honest, this is the first time I’ve seen any negative effects of stevia and I’m concerned because I use it quite often for sweetening my tea – and I drink a lot of tea. :)
    2. If you stay under the amount mentioned in the video, does that mean it’s harmless or simply within safe levels?
    3. How does the amount you mentioned in the video translate into daily allowance when using liquid stevia? (a typical variety available, such as NuNaturals organic liquid)

    • HK

      I have the same question Melanie. We have been using stevia for years and now I don’t know what to do. I only use about 1/8 tsp at a time and maybe do this 2-3 times a day. I have no idea how this compares to the “safe” amounts talked about in this video. since seeing this i have started to decrease the amounts i use in my tea and smoothies and I’m actually finding that 1/16 of a tsp works fine too. hopefully we can get answers!

      • wandakate

        I’ve used it for years as well, and I seem to be fine. I only sweeten green tea with it and not anything more and maybe 2 glasses per day at most. I do think it’s more safe than ANY of the other sweeteners.

    • Shoshana

      I too am a sweet tea drinker and was so excited to find a natural sweetener. I have been using at least double the safe amount of stevia for 6 years. I’ve suffered with severe dry eyes for the past two years and found out that my testosterone and progesterone are critically low. Today I typed in “stevia testosterone” on the web and found the following article:
      I’ve discovered that a large amount of stevia decreased testosterone in male rats by 40%. A Brazilian doctor found that it stops ovulation–which explains my low progesterone. My endocrinologist could not explain why my testosterone was so low but I now believe stevia is the culprit. I hope that this information gets out there to protect women and men from a harmful supplement.

    • Sammie

      Don’t know how you could possibly stay under the limits. The organic stevia I use comes in 1g pkgs. 1 pkg = 2 tsp sugar according to the box. So 1/4 a pkg (1/2 tsp of sugar) more than the max of stevia a 150 Ib person could consume/day. No way would 2 drinks/day sweetened with stevia contain small enough amounts to be considered safe.

      • Bug-a-boo

        1) The packets are not 2 tsp – they are equivalent to two tsp sugar in sweetness
        2) The packers are mostly not stevia – pure stevia is supposed to be 1000 times sweeter than sugar – so the packet only has a very little bit of it – e.g. 1/500 of a tsp. The rest is a sugar-alcohol and filler so you can meter out a part of packet – instead of having one tiny grain to work with.

  • jmf

    I also use a lot of Stevia, and have for MANY years! I don’t like the flavor of my local water and add it to every glass I drink! What I have done to myself??

    • Maybe there’s something wrong with your local water. Have you tested it? tried filtering it? tried drinking water with lemon juice instead?

    • Lucía

      I don’t like water so I drink green tea! :D

  • Michael Greger M.D.

    Also be sure to check out my associated blog post Vitamin B12: how much, how often?!

  • Michael Greger M.D.

    Also be sure to check out my associated blog post Vitamin B12: how much, how often?!

  • Rj Dredge

    Is there any studies comparing stevia to sugar regarding health issues?

  • Linda

    I grow stevia on my patio, and use the leaves & stems in smoothies.  Do you have an opinion on whether unprocessed stevia plant parts would cause similar changes at similar levels?

    • Dazia

      THIS is what I have been asking! If any one knows, please tell us! I don’t like using processed crap any more. I’ve never used stevia as a flavouring, so I want to get the plant. My friend purchased one a few weeks back and it seemed like such a good idea. I’ve been doing research and every other article is either it’s good for you, it’s bad for you. No one can decide and I can’t get a finalized answer lol.

  • Wow, this is scarry….I use tons of it! :/

    • HK

      so do I and have been for about 10 yrs!!

    • Soldier

      While it is concerning and I hope we get a clear answer, we should try to avoid using a ton of anything! Even a water in excess is not good.

      • wandakate

        SMART! Everything in moderation…Stevia is better than equal or splenda or NutraSweet or regular sugar or sweet n low.

    • Waveboy

      Swap out that stevia crap for Date sugar ;)

  • Martie

    I’d like to see some more information to this segment. What does this bacteria in the gut do? I use stevia and well over 4.5 grams per day. What is the alternative? What about growing your own? Can you follow up please with more info?

  • that’s about harm, what about nutritionscale with other sweeteners?

  • Erin

    Wow, this is news. Is there an assessment of Lakanto, another reportedly non-glycemic sweetener?

  • Are you aware that the study you refer to may have been funded by the Artificial Sweetern Industrial Complex corporations?
    Can you please update your video to include recent studies that show stevia has does not have “mutagenic compounds are produced in our stomach”?

    • TR M

      Can you provide some URL or journal links? I’m interested in both sides of a story and would like any info on Stevia. Thanks.

    • T. R.

      Posted on Sept. 10, 2011 pretty much stating it can be safe and provides a link to an FDA study, if we want to give weight to them. It also depends on WHAT BRAND you use. If it has more than 2 ingredients, you should rethink your brand. That part I found in doing my own research.
      The info is out there and the time and energy you put into uncovering it is well worth it.

    • It seems that Dr Michael Gregers might be OFF on his claims that “mutagenic compounds are produced in our colon”
      Here are a few things I found that also need to be considered:

      1.) Companies can get away with calling their products “stevia” even through the only part that is stevia is the chemically extracted compunds ‘steviol glycoside’ (the four major ones being stevioside, rebaudioside A, rebaudioside C, dulcoside A that add up to only about 8.5-17 of the whole leaf) and not the unprocessed whole leaf.

      2.) Extracted elements do not equal the whole compound. The product that he refers to is experiments done with very high concentrations of steviol glycoside and not the whole unprocessed leaf.

      3.) As far as health affects and possible carcinogen
      A.) His research is from the 1990’s more recent studies to not give the same results that he claims
      B.) I find it concerning that Dr Greger has yet to answer specific questions about the studies from several people who asked questions over 14 months ago.
      C.) Two Wikipedia pages have several references that contradict the claims that Dr Greger makes that “mutagenic compounds are produced in our stomach”
      “A 1985 study reporting that steviol may be a mutagen[7] has been criticized on procedural grounds that the data were mishandled in such a way that even distilled water would appear mutagenic.[8] More recent studies appear to establish the safety of steviol and its glycosides. In 2006, the World Health Organization (WHO) performed a thorough evaluation of recent experimental studies of stevia extracts conducted on animals and humans, and concluded that “stevioside and rebaudioside A are not genotoxic in vitro or in vivo and that the genotoxicity of steviol and some of its oxidative derivatives in vitro is not expressed in vivo.”[9 “Safety evaluation of certain food additives: Steviol glycosides” The report also found no evidence of carcinogenic activity. The report also suggested the possibility of health benefits, in that “stevioside has shown some evidence of pharmacological effects in patients with hypertension or with type-2 diabetes”,[9] but concluded that further study was required to determine proper dosage.
      The European Food Safety Authority evaluated the safety of steviol glycosides, extracted from the leaves of the Stevia rebaudiana Bertoni plant, as sweetener and expressed its opinion on 10 March 2010. The authority concluded an Acceptable Daily Intake (ADI) for steviol glycosides, expressed as steviol equivalents, of 4 mg/kg-bodyweight per day.[10 “Commission Regulation (EU) No 1131/2011”

      D.) In 2009, FDA considered “Rebiana (rebaudioside A) to be Generally Recognized As Safe (GRAS)”.[50]
      “Two 2010 review studies found no health concerns with stevia or its sweetening extracts.[51][52]”
      “millions of Japanese have been using stevia for over thirty years with no reported or known harmful effects.[57]”
      “In 2006, the World Health Organization (WHO) evaluated experimental studies of stevioside and steviols conducted on animals and humans, and concluded “stevioside and rebaudioside A are not genotoxic in vitro or in vivo and that the genotoxicity of steviol and some of its oxidative derivatives in vitro is not expressed in vivo.”[59]”

      E.) Positive affects from stevia have been noted:
      “a 2009 review study found that stevioside and related compounds have anti-hyperglycemic, anti-hypertensive, anti-inflammatory, anti-tumor, anti-diarrheal, diuretic, and immunomodulatory actions.[53]”
      “In relation to diabetes, studies have shown stevia to have a possible trophic effect on β-cells of pancreas,[15] to improve insulin sensitivity in rats,[67] and possibly even to promote additional insulin production,[68] helping to reverse diabetes and metabolic syndrome.[69]”

      4.) The amount of ‘stevia’ being referred to in human dosage recommendations is almost a teaspoon. To be clear the recommended dosage refers to just the ‘steviol glycoside’ compounds and not of the whole leaf. To get that much of the ‘steviol glycoside’ compounds you would have to eat about 5 teaspoons of whole leaf stevia per day!!!!
      Additional facts from

      5.) “The plant was used extensively by the Guarani people for more than 1,500 years, and the plant has a long history of medicinal use in Paraguay and Brazil.”

      6.) “Japan currently consumes more stevia than any other country, with stevia accounting for 40% of the sweetener market.”

      7.) “China is the world’s largest exporter of stevioside.”

      8.) “ethanol or methanol as solvent” to extract the stevioside Rebaudioside A

      9.) Bitter taste: “Glycosides are molecules that contain glucose and other non-sugar substances called aglycones” Some of the tongue’s bitter receptors react to the aglycones.

      10.) History of being banned (1991-1994) most likely caused from the artificial sweetener corporations! “In 1991, after receiving an anonymous industry complaint, the United States Food and Drug Administration (FDA) labeled stevia as an “unsafe food additive” and restricted its import.[40][72][73] The FDA’s stated reason was “toxicological information on stevia is inadequate to demonstrate its safety.”[74]”
      But what was the real reason? “Arizona congressman Jon Kyl, for example, called the FDA action against stevia “a restraint of trade to benefit the artificial sweetener industry.”[75] To protect the complainant, the FDA deleted names in the original complaint in its responses to requests filed under the Freedom of Information Act.[40]”

      11.) Current FDA stance on crude (whole leaf) stevia
      “Is Stevia an ‘FDA approved’ sweetener?”
      Is the current FDA stance on crude (whole leaf) stevia simply another attempt to protect the financial interests of the Artificial Sweetner Industrial Complex? We could simply look at the FDA’s track record for an indication!

      • ScottTrimble

        Just wanted to point out that the ratio you give in 3.C. from the European Food Safety Authority of 4mg/kg of body weight equals the same ratio mentioned in the video of 1.8 mg/lb. of body weight, so perhaps the science hasn’t changed that much?

        • I am unclear by what you mean by “so perhaps the science hasn’t changed that much”

  • Linda G

    I was told by a chemist that processed anything is a problem. If you use Stevia it should be in pure form. It is not the Stevia plant it is the chemicals and other ingredients used in the processing .

  • geminibutterfly

    Forgive me, but I am going to be blunt here. I am truly sick and tired of a panic being perpetuated over EVERYTHING! This causes cancer…that causes hemmorhoids…this causes you to grow an extra hump on your back…c’mon people, CALM DOWN!!! Nothing, and I repeat, NOTHING is 100% safe nowadays. You think you’re eating 100% organic? You honestly believe that even if you grow your own garden, that the water you use is 100% pure? The soil is untainted? Just because you use no pesticides, your product is never going to be perfect. The very AIR you breathe is toxic, and that has more of an adverse affect on your body than anything you eat. There will always be conflicting reports, funded by competitors, looking to undermine eachother. We are all going to die of something, but chances are, it’s going to be from a stampede of chicken littles trampling eachother in a blind panic, before anything else. Stevia, even processed, is as close to safe a sweetener as you’re going to find.

    • Melissa

      Very true. If eating everything in its natural state was really that much better for you, our great, great grandparents should have lived to be much older, but in truth, life expectancy back then was not nearly as long as it is today.

      Same thing is true for exercise. Don’t get me wrong. I’m all for moderate exercise, but 150 years ago, people used about 95% of all their energy just to get food. They had to till the land with an ox or a horse; plant their crops by hand, harvest them by hand, process their wheat, corn, fruits, vegetables and meat (which they also had to produce themselves) by hand and then cook over an open fire and clean up the mess without indoor plumbing. Did it add to their life span? NO! Most of them died before they were 50!

      • Charzie

        150 years ago we had little sanitation and no antibiotics, among many other factors…most people died from microbial issues, not the food related diseases we currently suffer from. The lucky ones still lived into their 90’s and beyond. I am both science minded and a simple nature girl, so I know we need to keep a balanced perspective. The closer we can live to nature, the better off we are…it has gotten so man thinks he can divorce himself from evolution, or even do it better with fake food, pesticides, chemicals of all sorts, etc., even our treasured antibiotics are losing ground. On the other hand, I am thankful for many of our advancements…it’s all about perspective and doing the best we can I guess!

      • Mercedes Schrödinger

        Life expectancy is just the average age of everyone when they die, including all the babies and young children who used to die before the invention of antibiotics and vaccines. 150 years ago, anyone who made it to 20 had a better chance of reaching 80 than most people today. But average in all those dead babies, up to 20% dying before age 6, and it brings down the total “life expectancy” but doesn’t really represent the average age an adult can expect to reach if they make it through the critical early years.

    • wandakate

      You mentioned toxic air that we breath (into our lungs). YES, my neighbor just passed away. He was the lawn mower and caretaker for the property where I live. He went out there and breathed the toxic fumes from all of the planes that we see flying overhead…They (these planes) are spraying toxins into our atmosphere, mercury and other damaging elements, that we are now breathing into our lungs.
      A garden even with NO pesticides (think Roundup), are still NOT 100% safe by any means, because these planes are above us constantly ruining the air that we and the food breath. ALL of that poison is falling from the planes onto the food and messing it up, ruining it, taking vitamins and minerals away from it.
      It’s ALL part of the depopulation agenda of the elite ones (the powers that be) in the USA. All a part of the coming New World Order. Bill and Melinda Gates are the founders along with Henry Kissinger who has said, We are “useless eaters”. Bill said, “I agree”, and “dumbed down as well”. We are according to them STUPID, and we are of NO use to any of them, and they want us eliminated, thus this NWO of the depopulation agenda that is in full force with the PLANES. Sometime in my town I see 12 or 13 of them up there all at once going up and down all over the area.
      There is formaldehyde in our shots, as well as saline and mercury just to name a few toxins, and that is the flu shot I’m speaking of here. The Ebola vaccine isn’t safe either.
      What about GMO, is that pure, or safe, why of course not.
      An Organic has yet to be proven as much better than anything else, except it cost more $$$$.
      It’s all about $$$$ today, the almighty dollar.
      Our water is not safe, fluoride is not safe, GMO isn’t safe, Organic isn’t proven, our Shots are not safe, our gardens aren’t safe and now our air isn’t safe b/c of all this Chem Trails (CHEMICAL TRAILS). So, look up, and when you see them flying up there, you will know that is NOT normal
      condensation coming from them, no it’s more sinister than that, more like evil from the pits of hell. The pilots don’t care about you, they’re getting paid a pretty penny to spray the air, and unless we stop them it will continue until along with all these other things, we are all dead.
      Then they will only have those around that are beneficial and are NOT useless, birdbrained individuals…Have a good day.

    • Nutradoc

      I have been in integrative medicine for 30 years and I can see where you are coming from, you sound like my mother and some of my friend’s that are literally overwhelmed with the ‘do or don’t eat that’ mentality. Apparently though it is you that needs to calm down, no one is saying that this product will kill you and that you should stop using it, The good Dr. and others that have responded and are just participating in a discussion on this ingredient…nothing more than this. Yes, the Dr. could have used more up to date research instead of leaving it where he did. But what you need to know is that we are all responsible for collecting data, and if you are not scholastically equiped to be able to judge what is real and what isn’t, then you need to find someone that is.

      As you have said, we live in a toxic world…so if we do not try to do our best to educate ourselves as to what to stay away from then we are just sheep. Buying organic isn’t 100% fool proof, but it is better than stuffing our faces with garbage that we know to be toxic, and then just ignore the fact that it is just because you are overwhelmed. I give credit to those who try and protect themselves. if you saw someone coming after you with a club would you not defend yourself? If there were more people that ate healthfully and tried to stay informed and were proactive the world would not be as toxic as it is today, and you would hopefully be less stressed. All the best…

  • AlizaCherche

    I saw an article on this site by Dr. Greger stating that agave nectar is a superior sweetener, which I know is not the case. I question whether this site is biased.

  • Jennie

    what about growing the plant and using the leaves as apposed to using the store bought supplement. Is the plant leaf itself safe, without all the processing?

  • Susannah

    I don’t like the way stevia tastes (bitter and ultra sweet), so I’m not surprised with these findings. I’m just now drinking a protein drink make with high quality ingredients and of course Stevia is included. It has that awful aftertaste reminiscent of artificial sweeteners. How can we get the food companies to stop putting it into almost everything? I don’t care if people add it or any other natural or manufactured sweetener, but I don’t want it showing up in everything (as if it’s the next “free ride” for sugar addicts.

    • Freddie Sorensen

      I buy dried stevia where I buy tea and use it in my den pitcher with tea can also be blended into powder in the other things I do not like the formatted products? But really everything in moderation!

  • Jonathan

    So does stevia act as a contraceptive? Is it safe for consumption?

  • Linda

    Thank you JD,
    I was beginning to feel panicked since I use a lot of organic pure stevia extract powder… glad to see there is nothing to worry about despite the older studies sited in the video above.

    • Thanks for the response Linda.
      I do find it a little concerning that Dr Greger (or his sidekick “Toxins”) has not responded to any of the information I included in my response.

  • Alex Gonzalez

    What about stevia extract drops or whole stevia leaf?
    Are those bad too?

  • Vicki

    Stevia purchased at the grocery story has all kinds of additives that suppose to make it taste better. You must read labels! Only use PURE Stevia that you can only find at health food stores.

  • Anna Gee

    I take around a quarter teaspoon of Stevia per day in my smoothie and my liter of apple cider vinegar drink, so half a teaspoon per day. Too much ?

  • Anna Gee

    Is there evidence yet on the exact damage Stevia does in long term daily use, such as a five year or ten year study?

  • Anna Gee

    What about coconut sugar? is that as healthy as date sugar? And what about all coconut products. I read that coconut is a superfood which can do no wrong if it is not processed highly. I drink the water by the quart from boxes sourced in Thailand, but I prefer the nut opened fresh off the tree.

  • sammie

    1 tiny package (serving) of stevia = 1 gram so even I package is way over the limit :(

  • lbc

    Can you clarify if the effects are cumulative? Also, does “mutagenic dna damage” mean that ingesting stevia can literally mutate our dna?!? I’m concerned because, as a brca1+ breast cancer survivor, I completely switched over to stevia for baking and beverages.
    This sounds a lot like what they said about saccharine once upon a time, when it was killing rats, but it was ok to have a few Tabs.
    Many of the vegan recipe sites I follow are using xylitol, is that a safer choice than stevia? TY!!

  • Susan

    At some point a few years back, the FDA or Michael Taylor. Food Czar of the FDA and once a lobbyist of Monsanto (now its vice president in charge of policy) allowed Neotame, which is far more toxic than aspartame to be used in Stevia, and any organic sweetened food without telling the public or labeling the product as such. For that reason, I totally stopped buying anything with added sugars, including stevia, and have never looked back.

    I now add dried figs, or dried apricots to my tea. It re-hydrates the fruit while sweetening the tea and adding nutrition to my tea break.

  • Barbara

    Who in their right mind would listen WHO? Like the gov, they are in the pack pocket of big biz. For every negative study like this their is one or two that is positive. Do the research and make up your own mind.

  • Mike

    Isn’t Truvia a mixture of stevia/erythritol?

  • karlremmen

    Wonderfully researched comments. Thanks! I must point out in fairness to Dr. Greger that he did not say steviol is derived from the steviosides in the stomach, but in the colon. I myself badly want to believe in stevia. One of my favorite plants to grow and consume powdered or to buy in bulk green leaf powder!

    • Thank your for the correction karlremmen about Dr Greger’s refernce on location. He said colon not stomach. “mutagenic compounds are produced in our colon” Min. 0:40

      • Joseph Gonzales R.D.

        I’ll ask him if there is any update on the research. As you can imagine he is very busy. My job is to help translate the information he produces and we of course get so many inquires! I appreciate your patience (dang…2 years! so sorry) and I’ll do my best to reply as soon as possible. If possible, please send links to studies that you have found counter his stance on stevia. Wikipedia is hard to navigate and the first PDF is not opening for me (I am sure it did two years ago!!!). Thanks, JD Mumma!

        • Just adding my name here to be sure I receive an update on this topic. Thank you so much! :)

          • Did you see my new research posted below?

  • Janet Kirby MD

    I know a person who had to stop using Stevia because it kept causing headaches. This person had known ragweed allergy. Ragweed and Stevia are related.

  • Linda

    “Is Stevia Good for You” was posted 5 years ago and “Harmless Artificial Sweetener” was posted 6 years ago. Are there any new findings about these subjects?

  • suzi houston

    Ok what can you eat that is sweet? I was using stevia, then tried others that I thought were ok, , apparently you can’t eat anything anymore that is healthy. I like natural cane turbanado sugar, what is wrong with that used in small amounts? None of the others are good for you. with all the added chemicals and additives in our food no wonder we are so unhealthy.

  • Suzi H.

    Anything natural is better than chemicals

  • Stat

    I only use one Stevia product daily about one packet. The one I buy has only two ingredients – Inulin soluble fiber, organic stevia extract. This is the only brand I have found that only has two ingredients. Im looking forward to more studies.

  • Charma1ne

    This is bad news for me. I have been using Stevia for years! Is there any new information about this subject and could someone perhaps answer some of the questions in the blog? Thank you for the information.

  • Andrew112

    hi. Does this study have any significance for humans? and this one on insuline gene expression. But no sure if I fully understand it…

  • vphelps

    Thank you JD Mumma for doing all this further research. One would think that if the Guarani people have been using stevia for centuries that problems would have shown themselves by now. Of course we are contending with differences between the whole food, purified extracts, and extracts mixed with other forms of sugar so that it can be legally sold in the sweetener section of the grocery store and there may well be problematic aspects with one form but not another. I would be very interested in any follow-on information on the subject.

    I’ve been growing stevia in my garden for about 15 years and use it both fresh, as well as dried and powdered. Additionally I use pure stevia extract (purchased at Trader Joe’s) to sweeten tart berries or other foods where the ‘green’ flavor of the whole leaf would be off-putting. I doubt I ever use more than the video’s recommended daily limit just because it’s so intensely sweet. Nonetheless, I’m always interested in educating myself on new solid scientific findings whenever an update might be posted.

  • Here is my most recent research on stevia – I hope placing my response here gets notification to those who wanted to be notified if I have more information.

    “Steviol glycosides were approved by the EU in 2010 after the European Food Safety Authority (EFSA) carried out a comprehensive analysis [] of all the available evidence and concluded they were safe for human consumption.
    “EFSA’s reviewing panel concluded that steviol glycosides are not carcinogenic, toxic or pose a risk to pregnancy or children.”
    “Acceptable daily intake: 4mg/kg body weight.” per day

    “Acceptable Daily Intake (ADI)
    The Acceptable Daily Intake (ADI) is 4 mg/kg body weight expressed as steviol equivalents based on GRAS Notification. This translates into 12 mg/kg/day of steviol glycosides, which are the sweet tasting components of stevia leaf extract used in Coca-Cola beverages. This means that a 150-pound (68 kg) person can safely consume 816 mg of stevia leaf extract every day over his or her lifetime without any adverse health effect. The amount of stevia leaf extract in vitaminwater zero glow sold by The Coca-Cola Company in the U.S. is 60 mg per 12-fl. oz. (~350 mL) serving.*
    *Amount as of May 2012; rounded up to the nearest 5 mg.
    Studies have been conducted in humans to document the metabolism of steviol glycosides. Steviol glycosides are not absorbed in the small intestine. They are broken down by bacteria in the colon into steviol, which can be absorbed. Absorbed steviol is converted into steviol glucuronide by the liver and is excreted in the urine.”

    “Neither stevioside nor its aglycone steviol have been shown to react directly with DNA or demonstrate genotoxic damage in assays relevant to human risk. The mutagenic activity of steviol and some of its derivatives, exhibited in strain TM677, was not reproduced in the same bacteria having normal DNA repair processes. The single positive in vivo study measuring single-strand DNA breaks in Wistar rat tissues by stevioside, was not confirmed in experiments in mice and appears to be measuring processes other than direct DNA damage. Neither stevioside nor steviol-induced clastogenic effects at extremely high dose levels in vivo. Application of a Weight-of-Evidence approach to assess the genetic toxicology database concludes that these substances do not pose a risk of genetic damage following human consumption.”
    Food Chem Toxicol. 2008 Jul;46 Suppl 7:S83-91. doi: 10.1016/j.fct.2008.05.002. Epub 2008 May 16.
    A critical review of the genetic toxicity of steviol and steviol glycosides. Brusick DJ

    “Overall, stevioside and rebaudioside A do not show evidence of genotoxicity in vitro or in vivo”
    “studies of DNA damage and micronucleus formation in rats, mice and hamsters have shown that the genotoxicity of steviol is not expressed in vivo at doses of up to 8000 mg/kg bw. Given that the available toxicokinetic data indicate that free steviol is absent from the systemic circulation in humans or, at worst, present at very low (negligible) levels, any concern raised by the in vitro genotoxicity profile of steviol is fully addressed by the fact that the genotoxic potential of steviol is not expressed in vivo, and by the negative genotoxicity findings for steviol glycosides in vitro and in vivo.
    “The results of toxicological testing indicated that steviol glycosides are not genotoxic, carcinogenic,nor associated with any reproductive/developmental toxicity.”
    Scientific Opinion on the safety of steviol glycosides for the proposed uses as a food additive1
    EFSA Panel on Food Additives and Nutrient Sources added to Food (ANS)2, 3
    European Food Safety Authority (EFSA), Parma, Italy – EFSA Journal 2010

    Primary statement from the Abstract: “concluded that steviol glycosides, including the widely used sweeteners stevioside and rebaudioside A, are not genotoxic.”
    “The current database of in vitro and in vivo studies for steviol glycosides is robust and does not indicate that either stevioside or rebaudioside A are genotoxic.”
    The safety of steviol glycoside sweeteners has been extensively reviewed in the literature. National and international food safety agencies and approximately 20 expert panels have concluded that steviol glycosides, including the widely used sweeteners stevioside and rebaudioside A, are not genotoxic. However, concern has been expressed in recent publications that steviol glycosides may be mutagenic based on select studies representing a small fraction of the overall database, and it has been suggested that further in vivo genotoxicity studies are required to complete their safety profiles. To address the utility of conducting additional in vivo genotoxicity studies, this review evaluates the specific genotoxicity studies that are the sources of concern, and evaluates the adequacy of the database including more recent genotoxicity data not mentioned in those publications. The current database of in vitro and in vivo studies for steviol glycosides is robust and does not indicate that either stevioside or rebaudioside A are genotoxic. This, combined with a lack of evidence for neoplasm development in rat bioassays, establish the safety of all steviol glycosides with respect to their genotoxic/carcinogenic potential.”
    Food Chem Toxicol. 2013 Jan;51:386-90. doi: 10.1016/j.fct.2012.10.016. Epub 2012 Oct 26.
    Steviol glycoside safety: is the genotoxicity database sufficient?
    Urban JD1, Carakostas MC, Brusick DJ.

    “steviol did not exhibit mutagenicity in either TA98 or TA100, with or without metabolic activation. No significant chromosomal effect of stevioside and steviol was observed in cultured blood lymphocytes from healthy donors (n = 5). This study indicates that stevioside and steviol are neither mutagenic nor clastogenic in vitro at the limited doses; however, in vivo genotoxic tests and long-term effects of stevioside and steviol are yet to be investigated.
    Environ Health Perspect. 1993 Oct;101 Suppl 3:53-6.
    Mutagenicity and human chromosomal effect of stevioside, a sweetener from Stevia rebaudiana Bertoni.
    Suttajit M1, Vinitketkaumnuen U, Meevatee U, Buddhasukh D.

    “The mutagenic activity of steviol and some of its derivatives,exhibited in strain TM677, was not reproduced in the same bacteria having normal DNA repair processes. The single positive in vivo study measuring single-strand DNA breaks in Wistar rat tissues by stevioside, was not confirmed in experiments in mice and appears to be measuring processes other than direct DNA damage. Neither stevioside nor steviol-induced clastogenic effects at extremely high dose levels in vivo. Application of a Weight-of-Evidence approach to assess the genetic toxicology database concludes that these substances do not pose a risk of genetic damage following human consumption.”
    Food and Chemical Toxicology
    A critical review of the genetic toxicity of steviol and steviol glycosides
    D.J. Brusick *

    • AllenPA

      Thank you very much JD!!

  • rierie

    -If the video only refers to the Stevia shown, (which all contain additives) I wonder if the safety levels change when we eat 100% pure stevia powders (which can be found at health food stores)? I wonder which kind was fed to the rats?

  • Stuart

    This video is almost 6 years old. It would be great to see an update. I’m sure many fans are interested, and I bet a lot of information has been learned about stevia in the last 6 years.