26/05/2016
We Use this as sweetener in Our Coffee, Choco, Juices.
Armin Q. Alcuran ND, CNC
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What Is Stevia? Side Effects, Safety Dangers and Health Benefits as a Natural Sweetener
You may have also heard the names Sweetleaf or Sugarleaf. Both refer to Stevia.
But is stevia good for you as they claim and you can safely put it in your homemade meal replacement shakes? Or is stevia bad for you like other popular alternative sweeteners and you should avoid it at all cost? Before we dwelve deep into mother science, lets take a look at the stevia plant and see what it holds underneath its lavish green pigments.
What Is Stevia Sweetener?
Stevia plant is a genus of 240 various species of herbs and shrubs belonging to the sunflower family (Asteraceae), and is found naturally growing in sub-tropical and tropical areas in Latin America. The species we care for is the Stevia rebaudiana Bertoni which is now being adopted as a sweetener around the world, just like it was used for centuries by the Guaraní tribes of Brazil and Paraguay.
The Guaraní have been drinking yerba mate teas sweetened with stevia in the raw leafy form more than a thousand years before western yoga hippies jumped on the herbal tea and stevia wagon. They call it ka’a he’ê (“sweet herb”). The plant wasdiscovered to the west by Moisés Santiago Bertoni, a Swiss botanist who emigrated and lived in Paraguay for about half his life.
Processed or pure stevia sweetener products today are used for many purposes – from its raw sweet leaves in Japanese teas to a processed powder or liquid bottle used to sweeten soft drinks, or even at home for baking and cooking. Though my grandfather didn’t have much luck germinating the seeds, most people agree its easy to grow. And it’s RIDICULOUSLY sweet.
But where does the sweetness come from?
It comes from two primary steviol glycosides – stevioside and rebaudioside. Rebaudioside is the sweetest (350-450 times the sweetness of table sugar) and least bitter part of the leaf, while stevioside (250-300 times the sweetness of table sugar) has that bitter aftertaste many people complain about.
That’s why some processed brands like Truvia and PureVia isolate rebaudioside and use it solely while other ‘natural’ or ‘raw’ stevia brands use the full spectrum of glycosides. And as you might suspect, problems arise when brands process the plant and add wierd substances to the mix.
So is stevia good or bad for you? Go get yourself a cup of green tea and let’s go find out.
Stevia Benefits and Advantages
Is Stevia Healthy For You?
The first thing i’m gonna do is go through the available science and examine the documented stevia health benefits . Yes, stevia is much sweeter than sugar and contains no carbohydrates or calories and everybody knows that. But are there other possible major benefits? Native latin-American used it for centuries as a sweet treat and breath-freshener, but do their claims of stevia being a health food with medicinal properties by itself hold any basis in reality?
In the early 70’s, Japan begun cultivating Stevia as an alternative to artificial sweeteners like saccharin after suspecting them of being a potential carcinogen. Fast forward to our days and stevia takes 40% of the sweetener market share in Japan, being used extensively in homes and commercial soft drinks.
But.. would you be surprised to learn that the Japanase are also using stevia as a treatment for type 2 diabetes? Check this out.
The Stevia Diabetes Connection
Researchers found that stevioside increases insulin sensitivity, reduces post-meal blood glucose and delays the development of insulin resistance in rats on a high-fructose diet. ‘This is all impressive” you’re saying, “but what about humans?”
One research studying the effects of stevia, aspartame, and sucrose on food intake, satiety, and postprandial glucose and insulin levels found similar results and showed that compared to sucrose or aspartame consumers, human stevia consumers had lower post-meal blood sugar levels and much lower post-meal insulin levels.
Best part? The stevia-consuming group didn’t have any of the sweet cravings sugar and some alternative sweeteners induce, and their blood-sugar profile was more stable.
Another study found some beneficial effect of stevia on diabetes and diabetes-induced renal disorders and concluded that their results ‘support the validity of Stevia rebaudiana Bertoni for the management of diabetes as well as diabetes-induced renal disorders’.
Another recent research evaluated how stevia affects diabetic rats and discovered that rats fed with doses of 250 and 500 mg/kg a day significantly reduced their fasting blood sugar levels, insulin resistance, triglycerides, alkaline phosphatase and omentin levels.
One more study concluded that rebaudioside A possesses insulinotropic effects and may serve a potential role as treatment in type-2 diabetes, while another study reached similar findings and found out that stevioside and steviol stimulate insulin secretion via a direct action on beta cells, and may have a potential role as antihyperglycemic agents in the treatment of type 2 diabetes mellitus.
This suggest to us that stevia and diabetes have more to do than we previously thought. Not only is it a good zero-carb diabetes-friendly alternative for sugar, but it actually helps increasing insulin sensitivity, which is especially helpful for insulin-resistant diabetic people.
Overall, it looks like an ideal all-around saviour for diabetic patients.
Stevia, Memory and Oxidative Damage
One study found an antiamnesic effect of stevioside in scopolamine-treated rats. Researchers impaired the memory of mice through the use of scopolamine (an anticholigernic found in the hallucinogenic devil’s w**d), gave them 250mg/kg dose of oral stevioside and then checked for memory retention.
They found that the stevioside-fed rats had largely reversed their memory deficit and even reduced brain oxidative damage caused by scopolamine, and concluded that ‘stevioside exerts a memory-preservative effect in cognitive deficits of rats’.
I’d be very interested to read further studies about the effects of stevia on memory preservation on humans. Who knows, perhaps an unexpected alternative treatment for Alzheimer was right under our nose all this time?
Stevia and Cholesterol
Researchers studying long-term feeding effects of stevioside sweetener on some toxicological parameters of growing male rats found that stevia taken alone in low-doses lowered cholesterol and was deemed safe to use and without any toxicological effects on body weight, organ relative weight, haematological and biochemical parameters or enzyme activities, though high-doses (1500mg/kg, an amount unrealistic outside the lab) did increase some toxic parameters.
The interesting part: taken together with an inulin soluble fiber – stevioside also increased HDL and lowered overall lipids. I find it very interesting, and if you choose to buy stevia perhaps you’d benefit from getting pure stevia extract with some inulin soluble fiber added to it.
Stevia, Hypertension and Blood Pressure
Researchers also studied the efficacy and tolerability of oral stevioside in Chinese patients with mild hypertension. After two years they found out that an intake of 500mg oral stevioside three times a day significantly reduced systolic and diastolic blood pressure compared to placebo.
Their hypertension situation improved and there were no reported or detected side effects. Interesting enough, less patients in the stevioside-group developed left ventricular hypertrophy, a pathological thickening of the heart muscle.
Another study with much lower doses (upto 15mg per kg a day) found no anti-hypertensive effects, and another one researching the mechanism of the antihypertensive effect of stevioside in anaesthetised dogs showed 200mg/kg doses of stevioside to normalise blood pressure and confirmed that ‘stevioside is an effective antihypertensive natural product’.
All in all the results are spectacular, even though we’re talking about very high doses.
Stevia and Atherosclerosis
Researchers fed 12-week old mice with 10mg/kg dose of stevioside next to a placebo group and found out that stevioside inhibits atherosclerosis by improving insulin signaling and antioxidant defense in obese insulin-resistant mice.
The mice had lower glucose and insulin levels (diabetes people, rejoice!), improved adipose tissue maturation and increased glucose transport, insulin signalling and antioxidant defense. They also had lower oxidised-LDL (“bad cholesterol”) and thus reduced atherosclerotic plaque buildup.
Impressive.
And because obesity, cancer and diabetes are very often associated with insulin resistance and high levels of oxidative stress and inflammation, stevia seems to be a king sweetener not only for diabetics looking for a zero-carb natural sweetener but for a wide array of the population as well.
And speaking of cancer…
Stevia and Cancer
One Japanese study from the National Institute of Health Sciences in Tokyo studied 50 male and 50 female rats in three groups for a period of two years. One group received stevioside at a concentration of 2.5% of their diet, second group 5%, and the third group served as a control and received no stevioside.
The results are interesting. Though there was a significant decrease in the final survival rate of the 5% treated rats, there was no noticeable difference in the organs and tissues of all groups when examined under a microscope, and females who took stevioside had a reduced occurrence of breast cancer tumours, and males showed a lesser severity of kidney damage. Also, the stevioside-fed rats weighted slightly less, which makes sense since stevioside has no calories or a glycemic response.
What’s interesting though, is that there was also a significant decrease in the final survival rate of the 5% treated rats. Another interesting and relevant study published by Nutrition and Cancer found stevoiside to have some anti breast-cancer properties in-vitro (in cells outside their normal biological environment, like a petri-dish) and decrease some stress pathways in the body that contributes to cancer cells growth.
Unfortunately I couldn’t dig the full data to check those findings more thoroughly, but they look promising.
Other Japanese researchers studied the inhibitory effect of stevioside on tumor promotion and found steviol glycosidesstevioside, rebaudioside A, rebaudioside C and dulcoside A to posses a marked inhibitory effect against inflammation and tumour promotion.
Rebaudiosides A and C inhibited inflammation in a similar activity to hydrocortisone, a commercially available anti-inflammatory drug, and stevioside was even more effective than indomethacin! Rebaudioside C showed half the inhibition rate of indomecthacin and quercentin, an antitumor promoting agent, but at doses 10 and 100 times smaller.
The groups treated with 0.1mg and 1.0mg stevioside mixture produced 2.2 and 0.3 tumours per mouse – while the control group without stevioside produced 8.1 tumours per mouse. We’re talking about 73% and 96% reductions! This is beyond incredible, but it doesn’t really seem to surprise the researchers: they’re saying that ‘a series of naturally occurring components of Compositae plants has been found to possess antitumor-promoting activities’.
They suggested that stevioside is better than some triterpenoids (“heliantriol C,11) pachymic acid, 3-O-acetyl- 16a-hydroxytrametenolic acid, and poricoic acid B16) for the chemoprevention of cancer.
Eagle-eyed readers will say that those are in-vitro studies that are notoriously inaccurate in ‘real-life’ biological environments (aka in-vivo), and that’s a very valid and realistic concern. With that in mind, the researchers say that “many compounds that are active in the EBV-EA assay have been confirmed to be inhibitors of tumor promotion in two-stage carcinogenesis tests in vivo.”
Take it as you wish.
Stevia Being a Sugar SUBSTITUTE
“Cancer, above all other diseases, has countless secondary causes. But, even for cancer, there is only one prime cause. Summarized in a few words, the prime cause of cancer is the replacement of the respiration of oxygen in normal body cells by a fermentation of sugar.” (Otto H. Warburg, 1931 nobel prize winner)
Lastly, and perhaps the most important:
Regardless of the very possible nutritional and medicinal health benefits of stevia, the simple act of eliminating sugar out of your diet is sure to bring benefits of its own. You already knew that sugar is one of the primary causes of diabetes, obesity and most other metabolic diseases, but did you actually know that cancer cells FEED on sugar?
And stevia helps you rid a lot of sugar out of your diet. Take a look:
Bonus: Stevia to Sugar Conversion Ratios
If you’re baking with stevia, a good rule of thumb to remember is that 1 cup of sugar equals about 24 stevia powder packets or 2 teaspoons of liquid stevia. You’re gonna need a tiny pinch, about half a packet (that’s 0.5g) – to achieve the same level of sweetness achieved by a 5g teaspoon of sugar.
Those measurements are from the SweetLeaf brand (comes with inulin insoluble fiber), so if you get a completely pure stevia – you’ll need to use much lower doses to achieve the same sweetness.
And by the way, this plant is ph-stable and resistant to high heat (heat stable up to 392°F) and is also freezer-resistant and water soluble, making cooking with stevia entirely possible. That way you’ll eliminate lots of empty calories out of your diet. It’s some highly potent stuff.
Dangers: Stevia Side Effects and Warnings
Is Stevia Safe to Use?
There were and still are some question marks about the dangers of stevia, mainly concerns related to reproductive toxicity and decreased fertility. So is it time to forget about the pill, ditch the condoms and feed on stevia like lunatic hipsters? Let’s take another look at mother-science and try to spot any adverse reproductive or genotoxic side effects of stevia consumption.
Contraceptive & Reproductive Stevia Dangers and Side Effects
Most contraceptive stevia concerns stem from a very old study dating back to 1968. After rumours of South American women using Stevia as a contraceptive, Professor Joseph Kuc performed that study to evaluate any contraceptive properties of stevia rebaudiana.
The results? Kuc found a visible and relatively long-term reduction in the number of offspring born to female rats he fed with a stevia solution:
A water decoction of the plant Stevia rebaudiana Bertoni reduces fertility in adult female rats of proven fertility.The decoction continues to descrease fertility for at least 50 to 60 days after intake is stopped. The decoction did not affect appetite and apparently did not affect the health of adults rats.
Not. Good. At all.
Professor Kuc does admit that his results aren’t necessarily valid for humans. First, he used some material from the stevia plant that isn’t ordinarily consumed along with his boiled stevia leaf extract. Second, he let his rats drink that mixture in such a high rate, equalling a person drinking about 2.5 litters of liquid in less than half an hour. And third, he used only one dosage level and not a variety of doses to establish what is known as a ‘dose-response’ relationship.
So should you feel intimidated by prof. Joseph Kuc’s findings? Is Stevia safe during pregnancy, breastfeeding or for those trying to have a baby? Let’s take a few more looks at science.
One study trying to discover fertility effects of chronic administration (two months) of Stevia found that it could effect hormones because of its glycosides having a similar structure to plant hormones like gibberellin.
“..chronic administration (60 days) of a Stevia rebaudiana aqueous extract produced a decrease in final weight of te**is, seminal vesicle and cauda epididymidis. In addition, the fructose content of the accessory s*x glands and the epididymal s***m concentration are decreased. Stevia treatment tended to decrease the plasma testosterone level, probably by a putative affinity of glycosides of extract for a certain androgen receptor, and no alteration occurred in luteinizing hormone level. These data are consistent with the possibility that Stevia extracts may decrease the fertility of male rats”
Oh my. You can take away our lives, but you can never take away our testosterone! Another study found a 60% decrease in seminal vesicle weight in rats compared to a control group.
But just like other foods, perhaps those side effects appear only in very high and unrealistic levels of consumption? Are there any studies that show no effect on hormones, especially when consumed in moderation?
One fascinating study comes to us all the way from the Chulalongkorn University Primate Research Center in Bangkok, Thailand (great city, you should go visit). The researchers wanted to study the effects (on a span of two generations) of daily stevioside consumption in hamsters.
They used four groups of ten male and ten female one-month old hamsters and fed the first group with a daily 500mg/kg dose of stevioside, second group 1,000mg/kg, third group 2,500mg/kg (!!!) and fourth group with 0, serving as the control group.
It’s important to note that the daily human stevioside consumption is estimated to be about 2-5mg/kg, much lower than the doses used in this study.
But guess what?
There was no significant difference between the average growth of either of the groups, and there was no difference at all between reproductive fitness and mating performance – no matter the dose of stevioside. Mating was efficient and successful in all groups, without any growth or fertility abnormality of either s*x.
“The results of this study are astonishing. Stevioside at a dose as high as 2,500 mg/kg did not do any harm to these animals. We conclude that stevioside at a dose as high as 2.5 grams per kilogram of body weight affects neither the growth nor reproduction in hamsters.”
Another study achieved similar findings where stevia extract didn’t affect male body weight, testicular weights and s***m count, morphology and motility. The researchers concluded that it has no toxic effect on male reproduction, at least in rats.
So what’s the verdict? Is stevia safe in moderation or even at high doses? I’d hate to give you such a vague answer, but sometimes I must. We simply don’t know enough – and more studies are definitely needed.
You have to remember that the doses used in those (rat-based) studies are very high and unrealistic. Nobody of us would go around munching on kilograms worth of leaves. If you eat enough of anything you’d get side effects. So from a contraceptive perspective, it seems to me as if stevia would be safe under its intended use as a sweetener. But again, more solid research in necessary.
Allergic Reactions and Sensitivity to Stevia
Just like other foods, the main scenario where stevia is sure to give you problems is when you’re sensitive or allergic to it. Weightology founder James Krieger said he knows of case reports of people getting atopic eczema (scaly and itchy rashes on your skin) and even people going into an anaphylactic shock from consuming stevia.
He said one study found 16% of infants with nasal allergies to be allergic to stevia, 34% of infants with bronchial asthma to be allergic to stevia and 64% of infants with atopic eczema to be allergic to stevia. Now, I don’t know where he got his numbers(update: I emailed him, he emailed me back this precious gem of a reference) but I do know and have heard of people showing allergic reaction to stevia – from difficulty swallowing to shortness of breath to dizziness etc.
But those usually appear in people who are allergic to plants in the Compositae or Asteraceae family – like chrysanthemums, marigolds, ragw**d or daisies. Check the comments section below, I predict it will be full of comments from allergic people. They’re the ones most likely to google stuff like ‘Stevia side effects’, after all :)
So yeah, a small percentage of people may show sensitivity and allergic reactions to stevia, and if you’re one of them – you’re probably better off without it.
Stevia Safety: Toxicity Possible?
We’ve already covered some toxicity-related studies of stevia, and none of them showed anything special, but let’s go check some more studies.. you know, just to be sure. And because we love studies.
One Japanese study involved almost 500 rats that were treated for about two years with Stevia rebaudiana extracts at levels of up to 1% of their total diet (550mg/kg) and concluded that there were no significant dose-related changes in the growth, appearance, organ weights, macroscopic or microscopic observations or haematological and blood findings.
The results obtained are supportive of the safety of stevia rebaudiana extracts, stevioside and rebaudioside A when consumed as sucrose substitutes by human populations.
I also found some leaks (can’t verify them though) from an unpublished report submitted to the European Commission by A. Douglas Kinghorn, Ph.D, saying his study (Food Ingredient Safety Review: Stevia rebaudiana leaves) showed no evidence of acute toxicity when he gave mice separate 2,000mg/kg doses of the sweet Stevia glycosides – stevioside, rebaudiosides A-C, dulcoisde A and steviolbioside. His results show no potential risk for acute toxicity for humans by ingestion of stevia rebaudiana extracts and constituents.
Acute toxicity was not demonstrated when separate 2 g/kg doses were administered to mice by oral intubation, indicating that a concentrated extract of stevia is less than 1/10 as toxic (acute) as caffeine.
Not enough evidence for you? alright.
In yet another Japanese study (H. Asaki and Y. Yokoyama. 1975. Dried-leaf extracts of stevia. Toxicological tests. Shokuhin Kogyo 18(20), 34-43) running toxicological tests on dried-leaf extracts of stevia, feeding male and female rats for nearly two months with stevioside being 7% of their diet produced “no untoward toxic effects” compared a a control group that received no stevioside. The study is written in Japanese so I couldn’t dig much and verify.
I also read of a study that found no toxicity or dose-related abnormalities but did find a significant decrease in serum lactic dehydrogenase levels, which is important in energy production without oxygen (aka “anaerobic”), but I couldn’t find a link to it or anything linking stevia to serum lactic dehydrogenase levels. Take it with a grain of salt.
One more study found stevioside to be non-toxic in rats who were fed with high oral 2,000mg/kg doses and showed no abnormal behaviour or organ damage. Researchers also found no cytotoxic properties at a concentration of 1.25g/L in an in-vitro toxicity test.
So overall, the vast majority of studies that I went through and available evidence shows no abnormal toxicity properties to stevia consumed in realistic amounts . You should be safe in this regard.
Mutagenic Stevia Side Effects and Cancer
You might have also read that in lab, steviol glycosides can be converted into a mutagenic compounds that may cause DNA mutations and promote cancer, and a lot of anti-stevia supporters seem to be using it as an argument.
We don’t know if the conversion of stevioside to steviol to a mutagen happens in humans,” says toxicologist Ryan Huxtable of the University of Arizona in Tucson. “It’s probably a minor issue, but it clearly needs to be resolved.
But have no fear, fellow readers. Devoted lab chemists down the basement in casa-del-Regev have gone on a predation journey to separate rumours from facts and hunt for scientific clues.
One interesting Japanese study titled Mutagenicity of Steviol and Its Oxidative Derivatives in Salmonella typhimurium TM677 found the mutagenic activity of steviol to be 1/3000 of widely-distributed mutagenic compounds like smoke, diesel exhausted gas and overheated meat.
The study also compared stevia to AF2 (a previously authorised food preservative in Japan) and found AF2 levels of 2mg (used to preserve 100g fish sausage) to be equal in mutagenic activity to.. 3000 stevia-sweetened cups of coffee! They concluded that-.the genetic toxicity of stevia can be regarded as negligible and safe, as long as we limit its use in ordinary amount for our daily life. Although further studies, such as the effect of heating on the activity of stevia, or the metabolic fate of its lactone derivatives in our body are necessary, the present paper suggests that there are no serious genotoxic problem with the daily usage of this low-calorie sweetener.
If you scroll back up to the section about stevia benefits for cancer, you’ll find a few studies showing that not only isn’t stevia a carcinogen – but it actually shows some anti-tumor properties and seems to be beneficial for the chemoprevention of cancer.
Stevia, Glucose Metabolism and Hypoglycemia
You might have also read that stevioside can interfere with the absorption of carbohydrates and disrupt the conversion of food into energy within cells, which might be an issue for kids. But that doesn’t seem to be the case.
Most studies in humans have not detected effects of non-nutritive sweeteners on gut hormones or glucose absorption.
But we wouldn’t rely solely on that, right?
I went searching for studies that found anything to back up those claims, but I found nothing very useful. The only relevant thing I could find was an overview paper summarising the available science and concluding that high-purity rebaudioside is safe for human consumption and has no effect on either blood pressure or glucose homeostasis.
But wait! Remember how I showed you that stevia reduced systolic and diastolic blood pressures before? It was the stevioside part we evaluated, and it’s the rebaudioside A we’re talking about now. Those are the two main ingredients of stevia, and they seem to have some differences in their properties.
There’s also a rumour popular on some nutrition blogs insisting that calorie-free sweetener like stevia can trick your body into a state of hypoglycaemia because having a sweet taste without an accompanying glucose tricks your body to prepare itself for sugar and lowers blood-sugar levels accordingly. When it gets no sugar, they say, the body releases adrenaline and cortisol to bring blood glucose levels back up by recruiting sugar from other tissues in the body.
Does the idea stand to the test of reality? To be honest, blood sugar altering hormones from oral glands communication to the brain sounds very probable. But science doesn’t want to agree, at least not in the cases of aspartame and saccharin – which doesn’t affect insulin levels. And here’s another study made on human volunteers that shows aspartame to have no affect on insulin.
But if you remember, I did show you that stevia causes some insulin secretion and increases insulin sensitivity in diabetic rats. How can that be? the secret might lie not in the sweet part, but the bitter part of the sweeteners. Researchers studying the effects of artificial sweeteners on insulin release found that while aspartame failed to raise insulin, bitter sweeteners like stevioside did have an effect.
So yeah, stevioside (and possibly not rebaudioside) has some effect on insulin but that effect is more of a benefit than a drawback, especially for diabetic patients. You don’t starve your body and feed solely on stevia and the studies we showed earlier showed a positive effect on insulin sensitivity.
It means that yes, stevia does secrete some more insulin – but it increases sensitivity to insulin and rids more sugar from the blood stream to the cells. Which, again, is especially beneficial for the prevention and treatment of diabetes type-II. So unless you already have some hypoglycaemia issues, stevia is unlikely to be a problem here.
Is Stevia Safe for Children?
First things first – removing sugar, cookies, ice creams and lollypops from the diet of your kids is the best move you can do for their brains, guts and teeth. Regardless of stevia. Several attempts to decrease children sugar intake were already made by trying to introduce stevia as a sugar alternative in children’s food products. Yet safety issues still rise up.
And it’s not facts that rise them up, but fear.
As far as I know, the Guarani population of Brazil and Paraguay have given stevia as a treat to their kids for centuries. Makes sense to me that it should have been ‘trial-and-error’ed by now and they would have stopped this practice if it proved to be harmful to their little ones. You know, the same reason we don’t go out to the forest and eat any wild mushroom we see. Lots of trial and error proved this to be fatal so we developed habits that go from one generation to the next.
With the available knowledge we have, there’s not a reason really to believe stevia is unsafe for kids.
The Verdict: Is Stevia Healthy and Safe?
As a scientist with over 15 years researching the safety of stevia and of many other plants used as food or food ingredients, I can assure that our conclusions in these various studies indicate that stevia is safe for human consumption as per intended usage, that is, as a sweetener. (Professor Mauro Alvarez, Brazil’s State University of Maringa Foundation)
The sweet (!) jury down the court halls of casa-del-Regev is ready to give the bottom-line verdict:
It is very probable that some stevia compounds posses some medicinal anti-inflammatory and anti-tumour properties, though the exact mechanism by which those compounds bring those effects isn’t precisely known yet. Natural stevia sweetener products are especially useful for type-II diabetic patients and the relevant science was very convincing.
On the other hand – we’d be glad to have some more conclusive studies when it comes to fertility and reproduction effects of stevia, so for now.. i’d say avoid it if you’re trying to concieve or if you’re pregnant. Just in case. You should also avoid it if you’re allergic to the plants in the Compositae or Asteraceae family (marigolds, daisies, ragw**d, chrysanthemums, etc) or if you just sense anything unusual.
Do remember that the studies we’ve gone through used doses much higher than real-life use, doses so high that almost any plant tested would probably produce some kind of side effects. And some of the studies were also in-vitro (petri-dish like environment), not always very applicable in a real living animal.
For non pregnant/allergic people, if all you do is use stevia sparingly as a sweetener for your tea and baked foods, you’ll most probably be completely safe. Make sure you choose a good brand with no harmful fillers, and preferable with inulin insoluble fiber for the possible HDL and lipid profile benefits. And always listen to your body.
As for me, I personally don’t use it much – and not because of all those stevia side effects and warnings. I simply like my coffee unsweetened and i’ll usually add some raw local honey (the cloudy-waxish type, no the commercial liquid ones) to my tea. It’s more of a whole food than a sweetener, and it’s a nice nutritional boost if you’re trying to gain weight or just wouldn’t mind the extra calories.
