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Why Stevia is Bad for You: Liver, Kidney, Gut, Immune and Blood Health is an updated post that shares why I now believe stevia to be bad for everyone, no matter how it’s used, whereas formerly I considered it safe if used in certain ways.
Since using it years ago, I’ve now been shown studies that specifically isolate the damage done to the liver and kidneys; so we are no longer speculating about why stevia might be damaging to one’s health.
Stevia is all the more dangerous because it does not cause immediate symptoms for most people. Instead its insidious behavior affects the long term health of organs and gut health.
Why stevia is bad for you: What body systems it affects
As one study says of artificial sweeteners, stevia included:
The human body responds to these sweeteners in a very complex way. The sweetness of non-nutritive sweeteners is more potent than that of sucrose or high-fructose corn syrup.
This study evaluated the effect of stevia on feeding behavior, blood biochemical parameters, enzyme activities and immunological parameters in mice, compared to sucrose.
At both 8 and 16 weeks, data was gathered in several categories with the following findings:
- Stevia administrated mice groups showed a reduction in water consumption when stevia was not added.
- Type 2 Diabetes biomarkers increased significantly in mice who drank stevia water, versus control groups.
- Free radicals and nitric oxide levels were elevated after stevia consumption.
- Long term administration of stevia significantly increased cholesterol levels and significantly decreased HDL levels (serum high-density lipoproteins) and increased LDL levels (serum low-density lipoproteins). Levels of free fatty acids were significantly higher than those of control groups.
Regarding blood biochemistry, the results were pronounced:
- Stevia administration caused a significant reduction in hemoglobin and hematocrit levels, and RBCs (red blood cells) count, compared to control groups.
- In female mice, stevia showed a significant decrease in WBCs (white blood cells) count.
In reference to liver health, the results were again extreme:
- Stevia administration increased alanine aminotransferase (ALT) and aspartate aminotransferase (AST) levels. (AST and ALT are two of the liver enzymes doctors look at when trying to figure out if you have a problem with your liver.)
- Levels of liver triglycerides and cholesterol in male mice groups increased.
- Stevia significantly elevated liver cholesterol levels in both male and female mice groups.
The results for kidney health were also condemning:
- Stevia affected urea levels, but more so in male subjects, whereas creatinine levels were more elevated in female subjects. (The former can indicate kidney injury or disease in lab testing, whereas the latter indicates kidney problems, oftentimes a blocked urinary tract.)
- Damage to the kidneys upon dissection (and studies of the samples) showed congested blood vessels after 16 weeks of administration.
In addition to all these somewhat shocking results, stevia, the longer it was administered also affected:
- gut integrity and microbiome behavior
- the immune system, with increased IgG, IgE and IgA levels, all pointing to an increased likelihood of allergies, chronic infections and autoimmunity
- inflammation, with a significant increase in pro-inflammatory cytokines
What happens to stevia in the body
One of my favorite aspects of this study was the window it provided into what happens to stevia in the body and why it affects the liver and kidneys adversely.
Stevia is not absorbed in the intestine. Instead, the body converts stevioside into steviol (or stores it as stevioside). Steviol has the highest accumulation in the liver.
The body then tries to get rid of it via bile, but the removal and excretion of steviol by the liver negatively affects the bile metabolism. Chronic stevia consumption puts stress on the liver that results in an elevation of liver enzymes and altered bile output!
Stevia even elevates the level of liver fat.
Regarding the kidneys, this study calls steviol, “a toxic stevioside metabolite” and says it is:
… reabsorbed from the intestine to the blood circulation and accumulated in the kidney to be excreted in urine. The body begins to step up urination to facilitate its removal; a process known as diuresis.
This study adds that the proximal tubules were the site for stevioside accumulation. This, significantly, is the site of elimination for xenobiotics (drugs, food additives and environmental pollutants)! Any disturbance in this system reduces the body’s ability to detox xenobiotics!
And, how noteworthy, that the body puts stevia where it puts poisons!
My former beliefs about stevia
In case it’s helpful, how I used to eat stevia was to combine it and a totally natural sweetener, with the goal of circumventing what is sometimes called glucose confusion (which used to be my main concern). Here’s that concept as I once explained it:
‘My favorite concern about stevia is that the sweet taste on one’s tongue not followed by the expected ingestion of glucose can cause an insulin confusion. I love the idea that our sense of taste is connected to our body’s preparatory action!…
I like to combine stevia with one other sweetener. In a cup of tea, for instance, I put a bit of honey and a bit of stevia. I do this in baked goods, too, and often in my cookbook. This allows me to use less of the sweetener that I’m trying to limit, in this case honey, but to still achieve the level of sweetness that I prefer. My body is not faked out. It does receive glucose after tasting sweet.
I ran this method by my doctor who is very familiar with the insulin confusion that applies to artificial sweeteners. He felt it a good and safe solution.’
My updated view on stevia
As outlined above in the main article, I now believe the newer evidence outweighs the earlier guessing or incomplete studies on this topic.
For those who own my cookbook, I now think it’s safer to just omit the stevia, or use a natural sweetener, like honey, alone. Personally, I believe it’s better to save sweets for truly special occasions.
Most days, I do not sweeten any of my food. Even waffles and porridge, I just add a small amount of coconut oil (for the waffle) or non-dairy milk (for the porridge) + sea salt. No sweetener. It’s delicious and very satisfying.
Why I stopped using stevia
I didn’t know about the studies I share in this article when I stopped using stevia.
Instead, I stopped using it for two reasons: my current doctor advised against it. And, I no longer wanted to cultivate the need for something sweet.
About fifteen years ago, I was addicted to sugar. Stevia helped me to overcome that, but brought new evils into my body, without me knowing it.
Sometime in the last five years, I began to more fully understand that sweets in general are not good for the liver or one’s overall health. I still really enjoy not-too-sweet of treats, but only very occasionally.
Giving up stevia was me admitting that it was doing unseen harm, and that I didn’t want to sweeten so many of my foods any longer.
Other possible concerns about stevia
- Stevia is linked by some native cultures with infertility. Historically it was even used in South America as a contraceptive. However, the studies that support this view have mixed findings. (1, 2) It may be wise to avoid stevia if you’re trying to conceive, especially if infertility is an issue.
- Knowing stevia harms multiple organs and the gut microbiome is, of course, enough reason to avoid it, especially while trying to conceive.
- With thyroid health in mind, stevia should not be used to get a sweet taste without any carbs. Specifically, our thyroid is taxed if we don’t have enough insulin. Insulin is what helps convert inactive T4 to active T3. (source) Insulin levels are usually low in those with low-carb diets.
- We may endanger ourselves and our thyroid health by maintaining a low-carb diet long term. I got both Hashimoto’s and adrenal fatigue (or HPA axis dysfunction) after years of a low carb diet with stevia.
- The main hormone that gets dysregulated in adrenal fatigue is cortisol, and cortisol has been shown to increase on a low carb diet. This means that a low carb diet is a potential adrenal stressor in susceptible individuals. (source)
Conclusion: Why Stevia is Bad for You
Through several studies in recent years, we can conclude that stevia has a variety of harmful effects. While not every person will feel all of these effects, they were indeed observed in lab rats consistently.
Stevia:
- ‘s sweet taste causes addiction.
- causes insulin resistance.
- changes the gut microbiome.
- significantly elevated levels of liver function enzymes, urea, creatinine, cholesterol, LDL and free fatty acids.
- leads to oxidative stress (as seen by the elevated level of NO and the reduced level of antioxidants).
- causes inflammation in both the liver and kidneys.
- affects digestion and liver function.
- contributes to allergies, leaky gut, autoimmunity and overall inflammation.
What are you thoughts or experiences with stevia?
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Renee Kohley says
I love this balanced approach Megan – I share the same viewpoint and this is a great resource to share! Balance is key in just about everything!
Megan Stevens says
Well said. I’m happy to hear you share this view. 🙂
Anna @GreenTalk says
I grow stevia. (What a surprise.) I also worry about the white stevia since the plant is green. How do they make it white? I don’t taste the licorice taste. It is really sweet and a little bitter. Someone told me awhile ago that fat reduces bitterness. What do you think?
Megan Stevens says
I don’t know anything about white stevia, Anna! I’ll have to learn more on the subject. Thanks for mentioning it. Yeah, it’s funny that I don’t taste the bitter in stevia that so many folks mention. Maybe b/c I eat so much fat? 🙂
Sharon Devi says
Think what Anna @GreenTalk meant is that Stevia leaf in it’s natural whole-plant state is green. The Stevia that you are using & recommending (NuNaturals – NuStevia Reb 99) & the pictures that goes along in this post shows that it is in a white powdered form (hence the “white stevia”). So how do they make it white, since it’s naturally green? I’m also wondering the same.
Megan Stevens says
Ha! Now I see that plainly; thank you! 😉 I don’t know what their refining process looks like. But it is a processed food, surely. Perhaps it’s benign, as it seems to be; but we consume it knowing it’s not a whole food, thankful for the benefit it provides, and the lack of symptoms. Of course, it’s not for everyone. One could definitely email NuNaturals and ask for a description of the refining process. This information is probably already available online as it is with items like xylitol.
Susan says
So this info you posted is not in consideration of stevia grown in your garden in a pure state? Also I am concerned that you have recommended honey… we raise honey bees and honey should never be heated… or used for baking/cooking … with heat… this can make honey toxic at worst and at best kills off all of the beneficial nutrients that make honey good for you.
Megan says
Hi Susan, thanks for your cautions with heating honey. No, the tests with stevia were not done with stevia from the garden, so it would be great for more testing to be done. My feeling on that personally is that in moderation it’s very likely fine.
JJ says
I read every ingredient list because I will likely feel like crap the next day from eating something my body doesn’t appreciate if I don’t.
I came across reb-A in a non-dairy ice cream and had no clue what it was so I did a little research. It’s stevia in a form that can be patented, like a drug, because stevia leaf, or any plant in its natural form cannot be patented. There is already now also reb-B and reb-M. One website I found said they make the the “pure Reb M molecule through fermentation, by engineering yeast and fermenting sugarcane” so it’s actually a genetically modifying process. I would be interested in knowing if these studies used the pure stevia leaf or a GM produced stevia molecule? Then we can wonder if these tests really tell us about the plant’s toxicity or the chemical/manufactured toxicity? I’m still open to the real thing being ok for human consumption if we use it moderately, like we should probably do for everything we eat, but anytime there’s heavy processing so there can be a financial profit for the manufacturer, I really have my doubts about it’s health safety.
Megan says
Hi JJ, the main study I cite actually used a stevia product by SweetLeaf. Two of the other studies I looked at used one of the isolated glycosides from the stevia leaf, stevioside. I didn’t check on all of the others to see if any of them used the leaf itself, but my guess is most or all of them used stevioside. I do think that small amounts of the green leaf used occasionally would be fine. The tests seems to really by going for what most Americans do, which is use stevia every day as a way to have more sweetener and more sweet in their lives without any calories, carbs or they hope, change to their blood sugar levels, and I think that point is a good one. Stevia used in that way is dangerous, even if it’s the green leaf, because that exposes the body to constant stevioside. It would have been great, though, if the studies had another group of mice that ingested the whole leaf ground up, to be sure of those results. Without that, and either way, I think you’re right to mention moderation in all things and avoiding the manufactured products.
JJ says
Thanks for responding! Yes, people basically try to ‘get around’ the difficulty of eating less sugar! I’m lucky that my body tells me very directly what’s not working, so I can’t get around the ‘work’ of taking care of it. Thanks for the info on the studies, and I totally agree that a side by side testing of natural state vs chemical state would’ve been very enlightening. <3
Megan says
I’m similar to you, JJ. While I got away with years of stevia, in most cases, I can not do this. I am glad to know now. Thanks for your thoughtful questions and conversation!
Emily @ Recipes to Nourish says
This is so helpful! I was wondering about it and have never used it before. I love how you use it, in conjunction with honey … I also love that you consume sweets with protein or fat.
Megan Stevens says
Thanks, Emily! I appreciate what you said. 🙂
linda spiker says
I like liquid stevia but am not a fan of the powder. Love your suggestion of using two sweeteners at once!
Megan Stevens says
Thanks, Linda! 🙂 I think most folks have only had the powder with dextrose in it. I’d like the Reb99 product to be more broadly used and available.
diane weismiller says
What’s REB99?
Megan says
It is rebaudioside A, one of the two glycosides within stevia that make it sweet. Reb99 is just one stevia product on the market.
Marjorieann1977 says
So interesting! Thanks for sharing this info. I was a firm believer in point number one, so it’s interesting to hear Kresser’s perspective on this – he is one of my trusted go-tos for research/fact checking!
Megan Stevens says
I’m so glad this was helpful. Point #1 is indeed an attractive, compelling one. I do like the concept. Yes, Chris Kresser is a great resource!
Katie Stanley says
NuNatruals liquid and Mountain Rose Herb’s green powdered stevia are the only two I have in my kitchen! I general try to consume my stevia the same way mixed with honey or maple syrup, fat and protein. 🙂
Megan Stevens says
Yay, love that!! Thanks for sharing!
Sonya Floyd says
Thank you. Thank you. I have been experiencing health problems at 73. I’ve been using Stevia for years. I’m experiencing some of the same problems as the rats!!! I’ll stop with stevia at once!
Megan says
Great to hear that this was helpful, Sonya! I’m so sorry and hope you get good relief over time as your body recovers. 🙂
Sarah Day says
It’s so nice to hear about your views on this! I agree that the mistake is cutting out all carbs 🙂
Politically Incorrect Health says
It’s so nice to hear about your views on this! I agree that the mistake is cutting out all carbs 🙂
Megan Stevens says
Yes. 🙂 Thanks.
Lindsey Dietz says
Yay! I can comment! I’m so glad you shared this post. Stevia gets such a bad rap among certain groups of foodies, yet it can be a lifesaver for many! We use it daily and have not experienced any adverse effects. Shared on FB!
Megan Stevens says
Great! Thanks, Lindsey! (I’m so glad you’re able to comment now! 🙂 )
[email protected] says
Have you ever tried Stevita?
Megan Stevens says
No, I haven’t. What’s in it?
Joy M says
Have there been any studies using the whole herb rather than the refined white powder? I’m curious if the sweetener consumed with the other constituents of the plant/leaf would be less harmful. I’m curious since I can grow stevia and have dehydrated the leaves but then become afraid to use them.
Megan says
Hi Joy, good question. I believe, unfortunately, that these studies apply to all stevia (or reveal a truth about stevia), whether the green herb or a more refined product. The reason is they are testing the glycosides found in the leaf. I just checked the main study I cited, and it’s true that they used a stevia product! It would have been better if they had used whole stevia leaf on a third group of mice. I checked two of the other studies I looked at, and they used stevioside. My concern is that the same health concerns will be true whether the leaf is tested with its constituents or the isolated glycosides: the glycosides present in the leaf or product (stevioside and rebaudioside A) are what cause the symptoms. You may be right that the other constituents in the plant balance these ingredients and make them benign … and perhaps used in small amounts, that could work … like putting whole leaves in lemonade occasionally, for example. But I think that anyone who grinds up the leaves into powder or uses the powder in bulk is going to still be exposing the body to large amounts of stevioside, which the body will then treat as something it needs to expel.
Joy M says
Thank you so much, Megan, for your research. I had thought to put stevia leaves in some of my homemade herbal teas that could use a touch of sweetener. But, you know, my homemade maple syrup works just fine and I won’t have to keep questioning myself when I use it. Thanks again!
Megan says
My pleasure, Joy, and that sounds great. I have landed there, too. 🙂
Vee S. says
Hi Megan,
Thank you for this article. Not sure why it took me this long to see it to read it! lol Are monk fruit and allulose any healthier to use? I am trying to limit sugars and would like a lower carb yet more natural sweetener to use.
Megan says
Hi Vee, you’re welcome and happy to help. There isn’t enough information on monk fruit yet, but the info on allulose doesn’t look good: “Due to its structural similarity with fructose, allulose uses the same transport and distribution pathways. But in contrast to fructose, the human genome does not encode for enzymes that are able to metabolise allulose leading to an almost complete renal excretion of the absorbed dose and near-to-zero energetic yield. However, in vitro studies have shown that certain bacteria such as Klebsiella pneumonia are able to utilise allulose as a substrate. This finding has been a subject of concern, since Klebsiella pneumoniae represents an opportunistic human pathogen. It therefore raised the question of whether a high dietary intake of allulose may cause an undesirable growth advantage for potentially harmful bacteria at mucosal sites such as the intestine or at systemic sites following invasive infection.” This comes from: https://pubmed.ncbi.nlm.nih.gov/34409930/
Although it’s “no fun” at first, where I’ve landed is to just eat less and less sweetener in and on everything. For example, I now put coconut oil, sea salt and sometimes pecan butter on my waffles or toast. When I do use sweeteners, I mostly use maple syrup or honey, but then most importantly, I stay active, so my body uses it right away instead of storing/processing it, which is hard on the liver. But I first went through many years of trying to make alternative sweeteners work. Sadly, I think sweets are best saved for special occasions. I hope this helps!
Sandy says
Maybe I missed it, but is this a “typical” study, where the subjects (rats in this case) are given unnatural volumes per body-weight of a product, and then studied?
If it is, then the results of course are skewed. Is the amount the rats were given equivalent to you and me eating a cup or more of stevia a day?
Because Stevia is actually a plant, I find it hard to believe that consuming the amount you would consume, of say mint when you make mint tea every day, would cause problems.
Can you comment on that please?
Thank you for your research. It is a great jumping off point, and I love the idea exchange.
Sincerely,
Sandy
Megan says
Hi Sandy, thanks for the conversation and questions. Although it seems to be unnatural volumes, the researchers decided how much stevia to use in the rats’ water using these dose guidelines: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4804402/ While controversial, they are well considered before being chosen as producing the most accurate results. I also find it noteworthy that the rats preferred the flavor of the stevia water to regular water, much like many humans, who would rather drink a sweetened drink. But no one likes a drink with way too much stevia; it tastes awful. Similarly, I think the rats’ water was sweetened palatably, or they would have chosen the plain water. The researchers used SweetLeaf stevia in the main study I looked at, so that’s another good insight into how much could be used and still have it taste good to the rats.
Dorothy says
We used to use stevia extract in the form of drops in a regular basis, and since started using monk fruit extract in liquid form. I add it to hot tea with collagen and as a substitute for another natural sweetener, or to sweeten something a little more. I don’t feel the need for sweetening everything, but could still be overdoing it. Would it be a safe alternative, or are there similar adverse effects from monk fruit?
Megan says
Good question, Dorothy. There haven’t been any good studies on monk fruit that I’ve seen. But the pattern that studies are showing with all of the alternative sweeteners is a little concerning. My takeaway is that we should all choose/save sweets for special occasions, and although it’s disappointing at first, we should veer away from sweeteners on a regular basis and get used to unsweetened drinks and only occasional desserts or treats. My focus for the last several months is finding how I like things (how I can make them taste great so I really enjoy them) either unsweetened, very lightly sweetened, or how I can use fitness to use up those sugars so my liver doesn’t have to process them. (This just means a brisk walk before or after a meal.) So yes, you might be overdoing it and want to reconsider monk fruit, or use it less often. A long answer lol!
Erin Koss says
Good stuff Megan! Thanks for boiling it down and highlighting the latest information. Funny when I started using alternatives including stevia and monk fruit, my suspicion was that we would eventually be back to, “moderation, moderation” and it seems we are. Using sweeteners available naturally and not processed makes my heart much happier. It also makes my head much happier as I try and reduce the energy spent on food management. Thank you as always for your beautiful work in the world. Much love.
Megan says
So kind, Erin, and I’m so glad the article is helpful. Yes, I agree with you; I’m happier, too, just using natural sweeteners in moderation. Much love back! 🙂
Dorothy says
I appreciate your thoughts as always, Megan, and your thoroughness. We probably don’t need a frequent taste of sweetness, even the “natural” ones, and it may cause us to crave more.
Megan says
Yes, thanks for sharing, Dorothy, too!!
Fernando says
I recently started cutting sugar out of my life, and started working out too. So for a pre workout i have been taking a scoop of C4 with water. It said zero sugars, but was sweet. Upon searching, found out it was sweetened with stevia. My question here is. Taking this one scoop a day, would have those long term effects, or are they so low in concentration, that the body can handle, since that is basically my only “sugar” intake.
Megan says
Hi Fernando, in my opinion, and it’s not one I came to quickly or with any excitement, I believe any amount of stevia is harmful to the body, and long term use of it, based on the studies, causes damage that it then takes years to repair, if a person chooses to. I think that even small amounts are dangerous, personally. It’s very hard for most of us, but I think the better goal is to try to quit all sweeteners except for maybe a treat once a week or once a month etc, depending on the person. I wish that health and exercise nutrition products would stop using stevia or provide an unsweetened version. Those do exist, as you may have seen, and while they taste bad, I think it’s worth the trade off. Maybe you can find a similar product without the stevia, and good for you to begin cutting out sugar.
dan says
Now been shown studies that specifically isolate the damage done to the liver and kidneys; so we are no longer speculating about why stevia might be damaging to one’s health. What studies are you referring to, as need to study not just your word…Thanks.
Megan says
Hi Dan, look under the section called, “What happens to stevia in the body”, and then click on all the highlighted orange links; they’re all studies. Best!