Artificial Sweeteners May Leave You Absolutely Gutted

Artificial SweetenersSeveral years ago, I covered the popular artificial sweeteners sucralose, acesulfame-k, aspartame, and saccharin, finding mixed results and little to confirm the widely-held view that they provoke an insulin response. I also wrote about diet soda in general, coming out generally against them while acknowledging the lack of hard evidence either way. But artificial sweeteners may be interfering with our metabolic response to food by an entirely different avenue: the gut biome. According to a new study (PDF) that has nothing at all to do with the cephalic-phase insulin response, artificial sweeteners induce glucose intolerance by altering the composition of our gut microbiota.

There were a few different stages to the study:

1. In mice, adding any of the artificial sweeteners (AS) – the researchers tried saccharin, sucralose, and aspartame – to their drinking water for ten weeks induced glucose intolerance. Mice in the water, water + sucrose, or water + glucose control groups all maintained normal glucose tolerance over the same period. The changes were sweetener-specific, with saccharin having the most pronounced effect.

2. Given previous studies showing alterations to the gut biome with AS consumption, the researchers wondered if these changes were involved with the glucose intolerance. They dosed the mice with various antibiotics. If changes to the gut bacteria were causing or involved with the glucose intolerance, eliminating the bacteria should have an effect. It did; antibiotic treatment abolished the glucose intolerance.

3. To confirm that the microbiota alterations were causing (and not simply associated with) the glucose intolerance, researchers performed fecal transplantations, transferring the gut biome from AS-consuming mice or glucose-consuming control mice into germ-free mice on a regular chow diet. Mice who received a transplant from the AS group developed glucose intolerance; mice receiving a transplant from the control group did not. It was settled, then. Saccharin-induced changes to the microbiota were causing the glucose intolerance.

4. The researchers then examined the specific alterations to the gut bacteria of AS mice, finding many similarities to gut bacteria trends in humans with type 2 diabetes.

I hear the cries already: “Ah, but those are just mice, Sisson. I ain’t no mouse and I only have one diet soda a day! Okay, maybe two.” Valid points. Luckily, the study also had a human component.

The last part of the study dealt with human subjects. The participant cohort was non-diabetic, 44% male, and 56% female. Each participant filled out a food frequency questionnaire and underwent various clinical tests to measure glucose tolerance, body weight, waist size, and other indices of metabolic health. Then, researchers scoured the results for connections between artificial sweetener intake (from diet drinks and other sugar-free substitute foods) and metabolic health markers. As it turns out, there were associations between AS intake and increased waist-to-hip ratio (a marker of central obesity), higher body weight, greater glucose intolerance after an oral challenge, higher fasting glucose, and elevated liver enzymes (which might indicate non-alcoholic fatty liver). And when they compared a subgroup of people who ate the most AS to people who ate none at all, the differences were exaggerated.

Okay, but it says it right there: people who ate the most AS were also the fattest. Couldn’t it be reverse causation? In other words: Overweight/obese people are more likely to use artificial sweeteners in an attempt to lose weight. They were already unhealthy and near diabetic to begin with; the AS are just along for the ride. AS consumption could just be a symptom of the obesity and metabolic syndrome. The researchers planned for that, actually, controlling for body weight and finding that the “increase remained significant.”

The researchers then chose a group of participants at random and analyzed their gut bacteria populations. They found that AS consumption in humans predicted certain shifts in the gut biota, similar to the changes seen in AS mice. And when body weight was controlled, the associations remained.

Later, they actually placed seven healthy volunteers who were not habitual AS consumers on a week-long diet containing the FDA’s maximal acceptable daily intake of saccharin. Oral glucose tolerance tests were given before and after the experiment. In 4 of 7 subjects, glucose intolerance worsened after the AS diet; the other three didn’t get worse, but they didn’t improve either.

This isn’t the first paper to show AS-induced disturbances of carbohydrate metabolism. It’s not even the first one to explore the effect of AS on the gut biome. Let’s take a look at some of older evidence supporting this most recent study’s findings.

First off, artificial sweeteners make it through the gut mostly unperturbed. The majority of ingested sucralose, for example, shows up in the toilet, meaning your gut bugs will encounter any Splenda you consume. If artificial sweeteners are going to affect your microbiota, the two have to meet.

Second, there’s a wealth of epidemiological evidence linking type 2 diabetes and artificial sweeteners. One study found that daily consumption of diet soda was associated with a 36% greater relative risk of metabolic syndrome and a 67% relative risk of type 2 diabetes. The San Antonio Heart study noted strong associations between diet soda intake and body weight, with the latter increasing in step with the former. And among middle-aged Japanese men, regular consumption of diet soda was linked to a significant increase in type 2 diabetes. Plus, overweight people who drink diet sodas consistently eat more total food/calories than overweight people who drink regular sodas. If the results of this study hold out, those links may be causal, not just correlative.

Third, other studies have found that artificial sweetener consumption can affect the metabolic response to subsequently eating food with actual calories. One small study looked at the effect of sucralose consumption on glucose metabolism in obese patients who don’t have diabetes and don’t use artificial sweeteners on a regular basis. They either drank water or sucralose mixed into water, then drank a glucose solution. If a patient drank sucralose, they released more insulin and their blood glucose spiked higher in response to the glucose drink than patients who drank water. Moreover, sucralose caused insulin to stay elevated longer than water.

Fourth, we’ve known for awhile that artificial sweeteners can affect the gut biome. A famous 2008 paper found that 12 weeks of sucralose had negative effects on the gut bacteria in male rats, including reduced beneficial bacteria, increased fecal pH, and inhibition of pharmaceutical bioavailability.

While the science is far from settled, I think there’s enough that we can start making some decisions about whether or not to consume artificial sweeteners. And this is sweet (pun absolutely intended) vindication for all the people who’ve reported gaining weight or binging or seeing higher postprandial blood glucose spikes after incorporating artificial sweeteners only to be ridiculed for their “anti-scientific beliefs,” their delusions and their conspiracy theories.

Researchers are finally teasing out what many of you have known all along: individuals have individual reactions to artificial sweeteners. What’s good for the lean, CrossFitting goose may not work for the pre-diabetic gander. And it’s probably our highly individualized gut biomes that determine our highly individualized responses to artificial sweeteners.

Lab mice are a homogenous bunch. They live in the same environments, eat the same foods, feel the same stressors, and presumably have very similar gut biota profiles. Everything is controlled. If a dietary change has an effect, it’ll happen across the board. Humans are a bit rangier. We lead different lives from one another. We eat different foods, have different personal and medical histories, carry different microbial auras, and house different microbial populations in our guts. Some of us – and our bacteria – will respond poorly to artificial sweeteners. Some won’t notice a thing. Some will even lose weight.

But if you’re one of the people to respond poorly, if your postprandial blood sugar is getting worse even though the “science” says it’s impossible, you’re not crazy. And you’re not alone.

There’s more to come on this topic. This study was just a preliminary taste, albeit an important one. Stay tuned.

Let’s hear from you guys. What’s been your experience with artificial sweeteners and glucose tolerance?

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About the Author

Mark Sisson is the founder of Mark’s Daily Apple, godfather to the Primal food and lifestyle movement, and the New York Times bestselling author of The Keto Reset Diet. His latest book is Keto for Life, where he discusses how he combines the keto diet with a Primal lifestyle for optimal health and longevity. Mark is the author of numerous other books as well, including The Primal Blueprint, which was credited with turbocharging the growth of the primal/paleo movement back in 2009. After spending three decades researching and educating folks on why food is the key component to achieving and maintaining optimal wellness, Mark launched Primal Kitchen, a real-food company that creates Primal/paleo, keto, and Whole30-friendly kitchen staples.

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115 thoughts on “Artificial Sweeteners May Leave You Absolutely Gutted”

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  1. I just avoid the whole AS debate altogether by avoiding them. Plain old water or black coffee is fine by me, thanks.

    1. Totally agree. Thankfully I never liked the taste of artificial sweeteners and flavours, nor the fizzy drinks either. Lucky escape I guess.

      1. I get strange looks from my co-workers but I prefer Perrier water..even the unflavored variety. The carbonation just gives it a pleasant bite.

        1. My employer put in the coke machine that can mix 100 different drinks instantly, sugary and artificial sugary. The also put in water dispensers with fruit added for a hint of flavor (berries, melons, etc.). There is always a line at the Coke machines, never a line at the water. The water with fruit has a delicacy that Coke products can’t beat.

    2. I avoid them too… I don’t feel well, for whatever reason, when I eat most sweet things.

      Interesting point that in Chinese medicine it’s the sweet taste that triggers problems. I don’t know any of the details, like if they are saying the sweet taste triggers insulin production, but worth checking into…

  2. Haha – “I ain’t no mouse, Sisson!”

    I’ve never really had much experience using artificial sweeteners. I think the name is enough to put my Paleo brain into defense mode. Thanks for the read, good to know there’s some research highlighting the negative effects that they can cause.

  3. Not that long ago I was drinking 2 to 3 Muscle Milk a day (this has AceK and Sucralose)….and was wondering why I craved it?? I would go to bed and actually say “yes!, I have a muscle milk in the fridge for morning!”. Then I saw an episode on Dr. Oz (don’t hate, you can still learn things from him!)…..talking about the trigger in the pleasure center of the brain and how AS can increase your waist size. So I self experimented. Cut out the muscle milk, waist size decreased. I’m usually a size 4, and I could still get my clothes on, but they were tight in the waist… hanging over, muffin top tight……attractive right?? I was somewhat confused about why I was gaining there only…..and gaining at all…..and I didn’t think it was possible I would find Size 4 clothes with a size 5 waist…nor did I want to! So, I switched my morning shake to berries, whey and goat milk. I contacted Muscle Milk to see if they were coming out with any natural shakes(yes, that addicted)…..R&D is working on an AS free version, using Stevia….not so sure about that either, so I will stick to staying as natural as possible!

    1. The fact that “Research & Design” is working on something that the average person might identify as “food” fills me with horror.

      1. Research and Design? Eh? First time I’ve heard something other than Research and Development :p

        I wouldn’t think it would take much research for a palio to turn away from something with the word “artificial” in its name 🙂

        Good article, lots of great info!

  4. I’ve found through N=1 experimentation that eating a bit too much sugar, or certain greens specifically Kale, that I will experience very specific…lets say.. lower intestinal problems. Once can of a sucralose containing beverage usually knocks the symptoms back or eliminates them. I certainly wouldn’t recommend a can-o-chemicals a day but AS may have some use reigning in an out of control subset of the gut biome.

    1. I’ve wondered the same thing. Can putting a Splenda in my coffee now and then help get rid of bad gut bacteria, particularly if I’m supplementing regularly with probiotics and thus replenishing the good bacteria?

    2. Please consider the negative impact AS has on brain health! There is a lot of research out there to suggest that even if it is ‘ok in the gut’ (for you personally) AS will still be chewing away at your brain – the same can be said for different forms of sugar.

      1. And read the labels on stevia products! I recently bought one that had just a small amount of stevia but was mostly made of sucralose! Threw it out.

    1. Stevia is not artificial. In fact, you can grow your own. Mark has written that it is Primal and perhaps even beneficial.

        1. OK. I don’t use it so I’m no expert. Not much of a sweet tooth and I use local, unfiltered honey when I want to add a little sweetness, or just take the edge off of something that is sour or bitter.

          I posted a link to Mark’s page on stevia, but it is held for moderation. LOL. You’d think they could set the site up so that internal MDA links were not held.

        2. @Harry, check out Abel James podcast with Dr. Josh Axe. He gets pretty heavy into artificial sweeteners, especially stevia. Unfortunately stevia has gone down the refined and processed road that so many of our foods have. As you know, once food corps get a whiff of changing taste, they’ll cut any corners they can to make it cheap and profitable.

  5. Okay, so there’s more and more coming out that really shows conduming artificial sweeteners is it really not a good thing. With that said, my current mode of operation, as I do enjoy them, is no more than one day a week of diet soda and usually only in one sitting with a meal or what have you. It’s not like I’m drinking diet soda all day. So my question, is having one or two diet sodas (or one large diet soda) one day a week really enough to make a difference?

    1. If you only have one a week, just enjoy the Mexican Coke made with real sugar.

    2. Hey Ryan, 1 or 2 a week definitely not as bad as everyday but I would say the problem could be the potential for over consuming sugar/refined carbs on the days you do have them. AS can lead to actual sugar cravings as the body is not receiving the sweetness it was being “told” it was having.

      There’s studies from the Washington School of Medicine showing a 20% rise in insulin levels drinking sucralose compared to water so sugar cravings potentially could impact you on those days more than non diet soda days.

    3. Since you limit yourself to once a week, why would you bother with a diet drink at all? IMO, the chemicals in diet soda are much worse for your body than the occasional non-diet version.

  6. We need to shout this from the mountain tops, AS is just not the thing to use. There are lots of naturally sweet things to eat without using them.

  7. Finally a real study on the topic. I determined they weren’t a problem for me a long time ago. Real sugar in any form most certainly is though.

  8. Like others of us I just avoid AS. The sweetest thing I consume is Primal Fuel. People look for all kinds of excuses to overconsume food. This discussion doesn’t seem like the usual MDA good science.

  9. I searched the MDA site and found an article about stevia where mark talks about the benefits of it- in moderation of course 🙂

  10. AS is an acquired taste, but boy, when acquired it does seem addicting. When you stop for a while it seems like you have to re-acquire the taste. I kicked the diet soda habit and now it does not taste good any more.

    I use Splenda to take the edge off plain yogurt and in coffee. I think I’ll try an experiment and eat my plain yogurt plain and my coffee more straight (I use cream).

  11. Followup research needs to cast a wider net. The 3 AS (aspartame, sucralose and saccharin) tested are the most common in processed foods. Nothing would surprise me about aspartame. Sucralose is already suspect as a biome antagonist. No opinion on saccharin, but I avoid it. Would like to see other AS tested, like stevia and monkfruit.

  12. This is a tough one for me. My diabetes precludes the use of any conventional forms of sugar at all. I have never been overweight and never consumed any AS previously, so I can’t say that AS contributed to my diabetes in any way. When I test my blood sugar after using AS, it is normal. That is not to say it is not causing changes to my gut biome or increasing glucose intolerance. I have not noticed any ill effects, but I don’t use a lot of it. Taste-wise I’m not a big fan of Aspartame, Ace-K or Splenda. I would also be interested in seeing more research on stevia, monkfruit and xylitol.

    1. I use a packet of Splenda a day and feel fine. I’d say a packet easily falls under the 20% part of 80/20.

      1. Unfortunately, honey raises my blood sugar above normal levels. I eat to my meter.

    2. Hey Anna, stevia looks pretty decent but ideally you want to get raw stevia leaf powder. It is going to be more of a brighter green color as opposed to the super refined white stevia you find in packets which is generally just an extraction from the glycosides in the plant.

      It seems best to always go with the purest form of something when possible even though i will still take a refined white stevia serving over another artificial sweetener any day!

      1. “raw stevia” the green powder is disgusting tasting. I’m sick of people recommending that – what a way to turn the public off of stevia altogether.

        White refined stevia does not have any evidence of being “bad for you”.

    3. Some research indicates a lot of type 2 is caused by excess fructose consumption, which is then recommended to diabetics for the low index reaction. Good to look into, as the research indicates for those with type 2 because of fructose, you can correct it by eliminating added fructose, as opposed to continuing to get worse because your doctor’s pushing high fructose agave to you as a replacement for all table sugar.

      Nothing like consuming twice as much of what gives you the condition because you have the condition :p

  13. Hey Mark another great post. 🙂 As to your point about the gut biome many people don’t realize that even though it’s dangerous to kill good bacteria, the ratios then get way out of whack which further exasperates the problem. Even though this is preliminary, thanks Mark for looking into for us. Now we can pass your articles onto family and friends who love eating crappy food! 🙂

  14. I drank so much diet soda that I’m surprised I’m still functional at all. I did it to 1) reduce my overall caloric intake, or 2) justify my ingestion of some other higher-coloric snack. I used to get funny looks from store clerks when I’d buy a diet soda and a sugar ladened candy bar at the same time. Makes no sense to me either … now.

    I went Primal in March 2014 and I haven’t had a soda since. I needed the fizz for a while. I satisfied that need with Perrier until June or July. Now, it’s spring water or unsweetened herbal teas.

    This is good information. “Shine the light … and the people will find their way”. – E.W. Scripps Co.

    1. Same here! I drank generous amounts of diet Coke DAILY from the time I was 18 until just recently (I’m 39), while also feeding my out of control sweet tooth with lots of cookies, candy, and ice cream, EVERY weekend.

      The only reason I quit drinking diet Coke is because I started first Whole30 on September 1. I haven’t had one craving the entire time. After reading this article, I’m wondering if ditching the artificial sweeteners has something to do with that.

  15. I am a fervent Diet soda drinker… all the time… here is the weird part. I know it’s bad, and when I try to reduce consumption, I get wicked acid reflux. I mean I am drinking water and get reflux!! Diet soda doesn’t cause this reaction. I think I broke myself! haha Anyone out there have any suggestions for why I seem to run counter to common sense?

    1. Have you tried club soda or a naturally carbonated spring water? If so, did you get reflux with them as well? If not, they might be useful to wean yourself from the diet soda.

      1. I tried those once before and actually enjoy them for the most part. They don’t cause the reflux… on the non-fizzy stuff. I think I am going to try and go that route again….. worth a shot and better than what I am drinking now.

        1. Paul, I was drinking 120+ ounces a day of Diet Coke. I would drink them instead of eat or snack bc they would fill me up. I started to notice that I always had a headache ALWAYS…so almost two months ago I stopped drinking them. I now grab a Lecroix sparkling water in the am (don’t love but enjoy the fizz), unsweetened tea, and water. No more bloat, burps, or headaches…did it cold turkey too. You can do it!

    2. Plain water can give me reflux, as well. I’ve had good luck with seltzer water, water with lemon or lime juice, Natural Calm (R). All acidic stuff – maybe just what your lower esophageal sphincter wants, I guess.

  16. I suddenly started getting a quite volatile reaction to Sucralose a few years ago. Invented as a pesticide (so poison basically), it’s in loads of stuff and the product that kicked it all off for me was a Sainsbury’s “be good to yourself” juice drink.

    Within a day of drinking it I got a rash on the inside of my arms that wasn’t raised and didn’t itch but was very visible. I tracked the offending item down to the juice (the only thing that was new) after literally typing “rash on inner arms upon awakening” and was immediately presented with the answer right at the top of page one of Google!

    The site was called Splendor sickness and apparently allergies to artificial sweeteners are common. I’m OK with Aspartame (tho I try to avoid it), but if I have just a tiny bit of Sucralose then I get a rash that takesTWO MONTHS to fade.

    You have to wonder – my body clearly reacts to being poisoned but sweeteners such as Aspartame are in everything from chewing gum and Berocca to aspirin coating and toothpaste. Just stay away!

    1. I have a similar — but different — story. Without warning, my eyes would burn, which triggered tears. But the tears, rather than soothing the burn, only increased it, leading to more tears. After about five minutes, the tears would stop burning and the cycle would end. This would happen a couple of times a month. Very odd! Then, entirely by coincidence, I read that the new generation of artificial sweeteners had been known to cause xerophthalmia (dry eyes) in some people. Hmmm. I’d begun using Splenda in my morning coffee several months earlier. So I stopped putting anything in my coffee but a bit of cream. The dry-eye-thing stopped immediately and has never occurred again. I still drink my coffee with only a bit of cream.

  17. I love aspartame. The hardest thing about this whole Paleo plan is not having Diet Coke. This study makes sense but it also makes me sad.

    1. From what I have read I have come to the conclusion that aspartame is bad for you. I find sweeteners taste awful if I consume them regularly. If you change your diet elsewhere, you may find you can taste better. Abel James talks about this subject.

    2. Wow, I don’t understand what you like about aspartame. The time or two I tried it, I thought it tasted awful. It also gave me an immediate headache.

      True, Paleio is initially difficult for anyone with any kind of a food/drink addiction, but the “withdrawal” part is temporary. It only took me a few days to kick sugar addiction once I made up my mind to do so. As I see it, the downside of Paleo is minor but the payoff is huge.

  18. I’ve come to rely on teeth cleaning (saliva producing) gum (Orbit, Trident, etc.) as an efficient solution to oral hygiene when I don’t have access to a toothbrush; this has got me wondering if I’m doing myself a net disservice here. Anyone know if the AS content in such gums is significant or have experience about this to share?

    1. Sean,

      Most sugarless gum and oral health products are sweetened with xylitol. It is a naturally occurring non fermentable alcohol sugar so disaccharide consuming microbes cannot process it into food. I understand it actual has the effect of reducing the oral biome and helps to recalcify teeth? It is not a zero calorie product but it is supposedly safe for diabetics as it has a low glycemic index.

      1. Thanks for this info, Jack! I’m trying to quit chewing gum, but I have had a chronic habit since I quit smoking 10 years ago. I still allow myself ONE piece of Trident per day because, well, I feel like my mouth needs it! But I’d prefer to get to the point where I don’t feel like I want/need it at all.

    2. Chewing gum is probably harmless and might eliminate (disguise?) breath odor, but it isn’t going to remove anything lodged between the teeth or beneath the gum line. IMO, you might be better off just doing a good swish with plain water when brushing isn’t an option.

  19. Great but scary stuff. Don’t forget about how methanol makes up part of aspartame and how it is oxidated into formaldehyde which can lead to lesions on the brain and also is a known carcinogen.

    This stuff is absolute poison to the point there is an actual Aspartame Toxicity Information Center! If you want to see shady politics at it’s best read the history of the approval of aspartame if you already haven’t.

    1. Apparently it takes about 300 cans of diet soda to result in as much formaldehyde formation as from eating one tomato. Limit yourself to 100 cans a day and you should be ok. 😀

      1. Hey Jeff, definitely feels like something out of a Michael Moore documentary. Im real familiar with that timeline now and covered it in my blog about aspartame. Another great bit are the pictures of Rumsfeld and Hull jr riding on the private plane of Hershey and General Foods, the first big purchaser of aspartame…

  20. I think artificial sweeteners are the absolute worst, for so many reasons. Physically and mentally I think they only do harm.

  21. I used to drink diet Dr. Pepper by the gallon. Since I started eating primally, I had to switch to something else. Fortunately, costco sells cases of san pellegrino mineral water for pretty cheap (super cheap if you do the per-bottle math). Fizzy mineral water and lime juice has become my go-to drink.
    Just the taste of super-sweetness causes further cravings for sweets for me. So I had to get rid of AS completely.

  22. Has anyone had weight gain or plateaued weight loss from Kombucha? The stuff I drink is very low calorie, carb, and sugar. It never fails that when I drink it I have a noticeable shift in weight the next day especially if I drink in the evening. No symptoms of a blood sugar spike but many symptoms that Mark describes from consuming artificial sweeteners. Very similar to drinking diet soda or zero calorie juice for me.

  23. Hey, great post! This is something that may affect a lot of otherwise
    primal folks.

    As a small experiment of 2 (hubby and I) we have used the powdered white (bulk) stevia powder from our natural food store for a couple years, in the iced tea (red rooibos) that I make at home.

    After our last two fasting blood tests I noticed that both of us had much higher than usual fasting glucose numbers. He is quite slim and very active and I am a bit overweight (20lbs) but neither of us was ever suspected to be pre-diabetic or anything close. Our numbers were usually something like 72 to 80. I was quite worried When we both began seeing numbers in the mid 90’s, and consulted some people at the store as well as doing some online research. According to what I found, stevia is quite capable of spiking fasting blood sugar levels in some individuals. So, we have stopped using it in the tea and drink it plain instead. Since then, the last test on myself shows a drop back into the 80’s. Interesting!!

  24. So three thoughts: 1) the phrase “artificial sweeteners” is more all-encompassing than just those mentioned in this article and the study Mark referenced. There’s also sugar alcohols which are known to “go right through” some people. I wonder how these …tol’s (sorbitol… which I personally can’t absorb-at-all, etc) compare when it comes to gut microbe impact and glucose levels and insulin resistance. 2) something that isn’t mentioned, but people that do use artificial sweeteners in general tend to think in terms of “a sugar substitute for drinks like soda or coffee”. However, there are many, many foods out there that also use them. So even if you aren’t gulping down diet sodas or pouring Splenda into your morning coffee, you might still be consuming these products and thus dealing with the side effects. Its worth it to always read the ingredient list. Typically speaking, if its sweet, but low in carbs, then there’s an artificial sweetener or sugar alcohol in there. 3) Its also worth mentioning that one of the core tenets of a paleo/primal eating lifestyle is avoiding processed foods or at worst choosing minimally processed foods. No matter how you look at it, 99% of foods on the market containing artificial sweeteners (not just limited to soda) are a processed food containing preservatives, fillers, etc that you won’t find naturally in nature.

  25. Artificial sweeteners are not the answer to anything much. They are useful, in my opinion, to get onto whey protein. After a while you can go to just whey, or a bit of banana, perhaps with some coconut cream. However, regarding the epidemiological studies, you may find that the people had sugar cravings and were diabetic and drinking soda was a way of combating the problem as it got worse (satisfying the craving for sweet things) rather than the artificial sweeteners causing the problem. Linked being the operative word. Jason Seib once said “Coffee is for healthy people”. Mark is kind of saying the same thing. I am not healthy and I take it occasionally, but my long term plan is to avoid it most of the time in the future.

    1. To each his own, and no offense intended, but it seems to me that whey protein is about as processed as anything edible could possibly get. I understand that it can be beneficial in certain instances for some people, but it makes more sense to me to get my protein the old-fashioned way.

      1. I agree with you. However, a few things. I may be wrong, but I don’t think whey is heated much during processing, and is a dessicated milk fraction only. Whey is probably less processed than plant protein powders and Mark S says animal protein is better. Huge doses or prolonged use may not be a great idea, but it is particularly convenient. It is a relatively cheap source of protein for the less well off. It is better than red bull or gatorade. As you say, it can be helpful for periods or for some people. I don’t think the bodybuilding guys and gals are going to give it up any time soon. It is more tolerated than other proteins by many with allergies to some proteins. I am not promoting whey protein, but defending a small use of sweeteners. In an ideal world, noone would consume powdered whey (liquid whey has been a health food in bygone days) but my comment is not ‘naked’ as Mark S has posted about whey and how it can be useful in some circumstances, as you say, and he sells it, so I am not stepping on the toes of the man that runs this joint. I find whey is a useful part of my diet, but perhaps not forever. Thanks for your valid comment, it adds to the ongoing debate.

  26. When I drink plain water I lose weight. Because I get so bloated I can’t force myself to eat. So I drink Diet Rite, which is sweetened with Splenda, so as to be able to get properly hydrated along with getting adequate nutrition from food. My dietician says that’s fine as long as I don’t drink more than six cans per day. My Mom, on the other hand, drank tea sweetened with Saccharin most of her life and had problems for years with low blood sugar. You really do have to figure out what works in YOUR body.

  27. Have not had and AS or soda since 2006 or so. I never felt good after any of them. I have always operated at peak with just real food.
    The longer I stay away from the phony stuff the worse reaction I have to exposure.

  28. OK Mark I accept the evils of sweet. Then why, pray tell, are so many of us cursed with a sweet tooth? Why, in fact, did we evolve with the ability to taste it and the instinct to enjoy it? I, for one, refuse to condemn my biology as a moral failing.

    1. Plenty resources on the net address this – some time/effort/reading is required.

      But no one is stopping anyone from eating a little, or a lot of sugar (sweet stuffs, or even processed foods in general) – in fact today there is more than enough to go around for everyone.

    2. I would not bring morality into it. It is not a moral failing, nor a sin, to enjoy or consume sugar. It is merely harmful to your body.

      1. Just saying a lot of the responses here have a judgmental, righteous ring to them, almost as if we were discussing sex, not nutrition. What’s up with that?

  29. Artificial sweeteners don’t do much to me, but I’ve always suspected that my gut bacteria are pretty tough little creatures. I never get intestinal symptoms or any sort of trouble from any “bad” foods.

    That said, I avoid them on general principle. They taste like chemicals (there’s a disgusting aftertaste to just about any artificial sweetener I’ve tried), they don’t do me any good, and I don’t need them. I’d rather eat real food and not turn myself into a lab experiment.

  30. This is timely info for me. I have never used artificial sweeteners of any kind until I recently started using branch chained amino acids (BCAAs) before and after workouts to try and preserve/gain muscle. The unflavored variety is beyond horrific tasting, impossible to make palatable with anything I tried. So I got several brands of watermelon flavored and they are actually quite pleasant and refreshing mixed with 10 oz water. They contain Sucralose and Acesulfame Potassium. I believe that the BCAAs do help with workouts and recovery and was pleased with them but I also have had some recurrent episodes of diarrhea since I started that I suspected may be caused by the BCAAs, since that condition is very unusual for me since I have been eating primal.

    Here’s an interesting tidbit I just read:

    ‘Splenda (Sucralose) is made by adding chlorine to regular sugar, increasing the number of chlorine atoms. Because of this alteration, Splenda passes through the gut undigested, which is what makes it “calorie-free.” ‘

    To me that actually sounds like a relatively benign form of sweetener but perhaps the additional chlorine atoms don’t have the same effect on the gut biomes?

    1. chlorine is basically bleach… used to kill microbes/germs… would you drinking swimming pool water?

      1. Uh, table salt is half sodium and half… chlorine.

        It’s not unusual that elements that are deadly on their own or in one compound may be harmless or beneficial in another.

        1. No, salt is not half chlorine, it is part chloride. “D”, not “N” in that word. Please look up the facts before you throw comments out.

    2. Re: BCAA

      I’ve bought two types of ‘pharmaceutical grade’ (no flavor) from one supplier:

      Cheaper one – tastes horrible and doesn’t mix well (I inquired of country of manufacture as it’s not stated – China)

      More expensive one – almost tasteless and mixes well (country of manufacture stated – USA)

      If I continue to BCAA then I’m happy to pay more.

    3. Bayrider, why would you be pleased with anything that could be giving you diarrhea? Don’t you think, perhaps, that your body is trying to tell you something?

  31. I’ve been mixing a drink of fresh pomegranite juice with lemon juice, both from our tree, then adding water. In trying to hedge all my bets, I mix xylitol, stevia, and if I need it a bit sweeter I’ll add a tsp. of raw honey.

  32. This article made me think of the other sugars out there.
    One called D-mannose, that is used to treat UTI’s.
    Now I’m wondering if D-mannose affects the gut microbiome and blood glucose levels? Anyone know?

      1. Thank you. I sure hope someone, Mark?, has an answer for these questions.

        Many women are taking D-mannose either for crisis treatment or maintenance doses for UTI infections. It is not recommended for pregnant women, and some believe they have lost their child over having taken D-mannose while pregnant. Surely then, D-mannose must have an effect upon the gut microbiome…and so those using this vital treatment need to know what that is.

        1. Wow! I’ve never heard that about D- mannose. Would like to know more. Do you have any links about miscarriage possibly related to it?

        2. Hi RenegadeRN, I couldn’t find a reply button to your most recent post to my last one, so am replying to mine.

          Here is what was recently sent to me…it is a quote and then I will follow with the link from Chris Kresser’s site. Her comment is at the bottom of the page, last one. I am thinking that as she posted it in a public comments that it is alright to bring here to allow others to follow the “sugar” questions.

          Author: Julia Comment: So good to see UTIs being discussed and to acknowledge what a big issue they are for Women. I have had UTIs for 10 years and was on a low dose antibiotic everyday for one year. Fortunately after a paleo diet and Dmannose I have had no problems for the past 2 years. Dmannose was a miracle for my UTIs. However a year ago I got pregnant for the first time at 38. I continued to take low dose Dmannose most days. My baby died at 14 weeks. I see from the above discussion that Dmannose is not recommended while pregnant. My pharmacist and the Company website suggested it was safe in pregnancy. Never the less I will not be taking Dmannose as I try to get pregnant again. Unfortunately cranberry is not effective for me so I am back to antibiotics as the only effective treatment and see my health being compromised again…it’s a double edged sword.

  33. The only item in which I use sucrolose (a/k/a liquid Splenda) is house-made ketchup. Which uses an entire THREE DROPS. You’ll excuse me if I don’t panic.

  34. Almost any industrial, chemically derived product is likely to be bad for you in some way. Like many, I avoid this by avoiding AS.

  35. I am diabetic and have been for nine years. I strongly dislike artificial sweeteners, sugar alcohols and stevia so I simply don’t use them and never have. If I really need a small amount of sweetening I will use sparing amounts of sugar. After nine years I am fairly accustomed to the taste of food without any sweetening unless it is extremely sour. My diabetes is strongly hereditary in origin and has stayed mild because I am careful what I eat and try to get some daily exercise in even if its just a walk around the block.

  36. I gave up all sweeteners, including AS, as part of a no-refined-foods-whatsoever plan about 6 weeks ago. There were some cravings in the first week, but now I don’t miss them AT ALL…any of them. I am delighted that the cravings (not to mention some nasty acid reflux issues) are gone. I think I’m on the road to healing numerous SAD issues, and find myself filled with the zeal of the newly converted. Note to self: lots of people just don’t care 🙂


    Suppversity covered this. Effects weren’t seen with aspartame, and if we’re going to rip on food frequency questionnaire studies that vilify fat, we should rip on ones that vilify non-nutritive sweeteners.

    Here’s a nice human meta analysis of the effect of NNS on body weight/fat:

    In short, if you want to drink diet coke instead of regular coke, go for it.

  38. My sister-in-law died at the age of 39 from a rare form of abdominal cancer. She was known for consuming at least one, but regularly several, diet cokes per day since high school. No one knows for sure what caused the cancer but the aspartame is highly suspicious. I myself have always hated the taste of diet sodas. Ick….

  39. Back in my soda drinking days, I went the full Monty: real sugar only (which, of course, later became high fructose corn syrup) – I could never tolerate the chemical taste of artificial sweeteners. In retrospect, I’m grateful for that!
    Now it’s a bottle of kombucha a day, one or two glasses of wine a month, and if I need a little sweetness in my iced green tea, stevia does the trick. But I prefer water most of all.

  40. I’ve highly cut back on diet soda the past few months, but for the occasional one I’d still rather have it than a sugary one. I don’t feel any effects of a possible insulin response from a diet soda when I definitely can from a sugary one, that’s enough for me. I prefer the taste now too, sweet things really don’t appeal to me anymore ever since my body has kicked the addictive effect of sugar.

  41. Ever since I quit putting Spenda in my coffee, my headaches have been reduced over 80%! It only took me a couple of days before I loved the taste of coffee without a sweet taste. 🙂

  42. The ‘researchers performed fecal transplantations’ in mice…

    What did you do at work today honey?

  43. Thanks for sharing! I definitely used to be addicted to artificial sweeteners..especially in sugar free gum! Cant even say the havoc that reeked on my digestive system.

  44. I have used splenda for a long time. Going primal, i have considered stopping, but at this time i have stopped so much, i just can’t give up sweet in my coffee and tea. i have stopped my diet sodas for the most part. What i wanted to add though is this: i have fibromyalgia, and using real sugar at all causes my symptoms to flare. Especially the all over pain. The AS does not do this. So using the real thing is definitely not for me. i hope to one day learn to drink my drinks without sweetener, but not yet.

  45. I have had an on-and-off problem with diet coke since I went off to college at 18. I think I drank so much diet coke in college that my blood stream was probably diet coke. I drank it before bed and first thing in the morning. I actually felt like water first thing made me feel sick.

    While I wasn’t obese, I do know that my diet coke breaks during the day often were accompanied by M&Ms or some other sugary treat. I thought I had an insatiable sweet tooth.

    I gave up all pop for about 7 years when I first was diagnosed with Crohns Disease. I wasn’t primal or paleo then. I wonder if we’ll find that these gut biome changes not only lead to diabetes, but can also lead to Inflammatory Bowel Disease in susceptible people like myself.

    Sadly I got back on the “sauce” a few years ago, I’m not quite sure why. And I saw my weight creep up. And up. And every afternoon diet coke was accompanied by a sugary treat.

    Since then, I’ve done a few Whole 30 and cut diet soda out (obviously) and saw my sugar cravings disappear. I go back to diet soda and back they come.

    I’m off the diet soda/soda again and really committed to Just Say NO to pop. If I get to the point in the future where I think I can handle it, I’ll try Coke for a super dose of sugar.

    Thanks for the great summary of the study. These things keep my strong and committed to staying away from diet soda.

    1. Thanks for sharing this, Virginia. I noted earlier that I am having no sugar cravings on my first Whole30 (it’s day 24), and after reading this article I think that the fact that I’ve ditched diet sodas has a lot to do with it. I’ve always known deep down that AS were evil…who knows what else they’ve done to me that I’m not aware of. I’ll never go back to them.

  46. I don’t drink coffee or tea so I just use erythritol (AS) to sweeten a cake or a pancake that I eat 2 or 3 times a month.

    QUESTION: Should I change the AS for dates for example, since they are very good to sweeten and are a fruit but a lil’ high in carbs or since I only eat once in a while using the AS is not a problem?

    Thanks (:

  47. I’ve never liked the taste of artificial sweeteners. Most of the diabetics I know have a long history of consuming diet drinks. I just consume regular soda and juices and enjoy every bit of them.

  48. How about Xylitol? I’ve been using it for about a month as a sweetener – I’m finding it’s ok for flavor, and doesn’t zap my blood sugar up…

  49. Thanks for the interesting article, Mark. I have been eating paleo for a year and a half and over the last few weeks have become more ketogenic to reach my goals. The morning before I read this article, I tested my blood sugar with my hubby;s meter and my BS result was 101. This made no sense to me as the day before I had eaten very low carb. After reading your article, I made the decision to go cold turkey on the artificial sweeteners. I love saccharin (Sweet N Low) and have used it for years in coffee, tea, amongst other things, usually in large quantities. 24 hours after not consuming saccharin (which almost killed me lol, I may have to give up coffee) my blood sugars have been consistently in the 70’s -80’s instead of the 90’s which is where they were staying despite the very low carb diet. I’m completely convinced the info in your article is correct and have had to readjust to the fact that I truly thought I was making a healthier choice when choosing saccharin but clearly was not for me. Thanks again for challenging us to be the best healthy version of ourselves.

  50. Hello Mark. Always great info from you and your team. thanks! … Can we get an updated report on artificial sweeteners, since this article is from 2014?

  51. Hello Mark,
    I’ve been using Swerve for about 3 years. What is your opinion of Swerve?