Jan 27 2014

Sucralose Fearmongering

It is easier to scare than reassure. We seem to be programmed for fear – fear of the unknown, of the “unnatural,” of things over which we have little control. Humans are what psychologists call “risk averse.” While the precautionary principle is fine, as far as it goes, risk averse decision-making can often lead to irrational decisions that are not in our best interest.

Food is a particular fear trigger because we also have the evolved emotion of disgust – a negative emotional reaction to the idea of exposure to or ingestion of contaminated or foul substances. The protective effects of this emotion are obvious, but it is a crude indicator rather than a precise toxicological detector.

Artificial sweeteners are a popular topic for stoking fears about what we eat. Aspartame has been a common target over the years, based on misinformation and distortion of the evidence.  More recently sucralose has been the target. Perhaps it’s because they have the word “artificial” right in the name. The industry uses the term “non-nutritive sweeteners” but this has not caught on in popular use.

Because of the internet and social media, misinformation not only spreads quickly, it keeps coming back around again and again. All it takes is for someone to post a link to a 5 year-old article on their Facebook page, and it can be spread around as if it is news. Often I am sent such items as if they are new, because those sending the article around did not check the dates on the original source documents.

Take, for example, this bit of fearmongering about Splenda (sucralose). These claims about sucralose, that it reduces GI good bacteria by 50% and increases the pH level in the GI systems, are based upon a study from 2008, but has been spread by Mercola (a notorious health crank). Many of the mentions of this information link back to Mercola, rather than the original study.

This is an excellent example of cherry picking – you can find studies that purport to show scary things about just about anything. There are tens of thousands of studies published every year, most of which are preliminary, with varying results. It just takes a bit of searching to find studies to support whatever view you wish.

Mercola writes:

The approval was given after the FDA supposedly reviewed more than 110 animal and human safety studies, but as you’ll soon find out, out of these 110 studies, only two were human studies, and the longest one was conducted for four days!

But then he bases his own conclusions on a single study in rats. The study did conclude that intestinal flora was decreased while pH was increased. It also found increases in the activity of enzymes that metabolize certain drugs in the GI tract. If true this could reduce the bioavailability of certain drugs. (Mercola apparently missed the irony of warning about reduced bioavailability for the drugs that he so often rails against.)

Since sucralose is approved by the FDA, the new study was cause for some concern. An expert panel reviewed the study in detail, as well as previous relevant research. They found:

“The Expert Panel found that the study was deficient in several critical areas and that its results cannot be interpreted as evidence that either Splenda, or sucralose, produced adverse effects in male rats, including effects on gastrointestinal microflora, body weight, CYP450 and P-gp activity, and nutrient and drug absorption. The study conclusions are not consistent with published literature and not supported by the data presented.”

This study was published after Mercola’s article, but this is exactly why you don’t jump on one preliminary study. I also notice there is no update on Mercola’s article citing the review.

The most recent systematic review of the health effects of sucralose is from 2009. They found that sucralose is completely safe.

Another strategy of fearmongers is to ignore the whole issue of dose. Mercola reports that a study of sucralose showed: “Decreased red blood cells — sign of anemia — at levels above 1,500 mg/kg/day.” However, the “FDA Acceptable Daily Intake for sucralose is 5 mg/kg.” This is right from the abstract of the study he is presenting. So – researchers found possible toxicity at doses 300 times greater than acceptable limits. I bet pretty much everything we eat has negative effects at 300 times the recommended use.

What about the issue of non-nutritive sweeteners contributing to weight gain? You will also find this claim common among sweetener critics. The data here is still a bit muddied. 

Long term observational studies do find a correlation between non-nutritive sweetener use and obesity and diabetes. However, it is likely that such studies are confounded by reverse causality – in other words, people use artificial sweeteners because they are already overweight.

Short term experimental studies, however, find that use of artificial sweetener is associated with reduced calorie intake and better glycemic control. These beneficial effects are offset and may even be eliminated by compensatory eating.

I don’t think the final word is in yet on this issue, but the most recent reviews show there is no large effect. There may be a small beneficial effect from avoiding sugars, as long as you don’t make up for it elsewhere.


We have decades of research and hundred of studies with non-nutritive sweeteners. Not just the FDA, but multiple agencies and organizations around the world have looked at all this evidence and concluded that they are safe.

Those who make a living out of spreading fear or a particular world view (usually based around the naturalistic fallacy), however, give a distorted view of the evidence, mainly through cherry picking.

Further, the fearmongering is dependent upon accepting a conspiracy-oriented view of reality. In order for the claims about sucralose to be true, then regulatory agencies around the world are either complicit or hopelessly incompetent. In addition, professional organizations must also be on the take or ignorant of their own supposed area of expertise.

I am not, however (as will likely be the accusation) preaching mindless acceptance of authority. I simply think expert systematic reviews are more reliable than distorted or cherry picked evidence with an agenda.

24 responses so far

24 thoughts on “Sucralose Fearmongering”

  1. Kawarthajon says:

    “I bet pretty much everything we eat has negative effects at 300 times the recommended use.”

    LOL, Steve, I think you’re on to something. Imagine eating 300 times more turkey or drinking 900 cups of coffee per day (based on drinking 3/day)? Makes me sick just thinking about it. How much diet soda would you have to drink to have 1500mg/kg/day? A LOT! Ugh, I hate the after taste from sucralose.

  2. SkepticalEsquire says:

    The industry should call them “alternative sweeteners”. I’ll bet they’d see less resistance to them from the woo crowd then.

  3. ccbowers says:

    Organized misinformation that makes use of fear is very difficult to counter. Even after the correction is communicated (and the correction almost never circulates to the same extent as the misinformation), the fallability of memory rears its ugly head yet again.

    The problem is that even if a person is attempting to get things correct, a significant percentage of people will not be able to remember which was the misinformation and which is the correct information. Given that the original topic was a fear-based topic, there is a tendency to rely on the cautionary principle when a person cannot remember if the concern is warranted. Add that to the percentage of people who maybe ideologically motivated on that topic, and the problem becomes worse.

  4. ccbowers says:

    “Food is a particular fear trigger because we also have the evolved emotion of disgust – a negative emotional reaction to the idea of exposure to or ingestion of contaminated or foul substances.”

    I’m not sure if this was intended, but you seem to be limiting the definition of disgust to food in this quote. That is definitely an important area for disgust, but it is my understanding that feelings of disgust can extend far beyond food/substances, and the same emotion occurs when people have a revolting reaction to other things, e.g. the mere sight of a spider or even specific human behaviors.

  5. tmac57 says:

    One tsp. of honey = 22 calories x 300 = 6,600 calories. Honey will lead to obesity and diabetes. 🙂

  6. Kawarthajon says:

    tmac57: Yeah, but honey is all natural, so it’s naturally healthier than “artificial sweetners”, no matter how much you have. 😉

  7. @ccbowers: spiders and other fears/phobias aren’t triggering exactly the same type of disgust. Taste aversions seem to be a special type of disgust that happens to be related to food intake. Getting food poisoning from let’s say bad Chinese food doesn’t make you forever ill whenever you see small cardboard boxes, or chopsticks…but the smell or thought of the food itself might send you over the edge. The disgust is mentally paired with the food stimuli, hence we have a particular cognitive tool that allows for such easy pairing. That was my reading of Dr. N’s intent here.

  8. tmac57 says:

    Kawarthajon- That makes me picture a cartoon where two obese diabetics are sitting in a Dr’s office waiting room,and one say’s ” Well,at least my diabetes is all natural,so I’m feeling pretty good about it”.

  9. Bronze Dog says:

    However, it is likely that such studies are confounded by reverse causality – in other words, people use artificial sweeteners because they are already overweight.

    I can definitely see how things like that would confound a study. I remember a scene from Rocko’s Modern Life where a woman orders an absurd number of snacks at a theater concession stand, “…and a diet soda. Gotta watch my girlish figure, after all.” It’s stereotypical, but I have no trouble imagining that some real people with weight issues might make a concession to a healthier diet by switching to artificial sweeteners for diet food and drink but use that as an excuse to “reward” themselves with indulgences that negate or override the benefit of losing the calories from sugar.

    I don’t know what sweetener it uses, but I lost about 20 pounds by switching from regular Dr. Pepper to Dr. Pepper Ten. I had to spend a couple months mixing the Ten with regular to get used to the aftertaste before I could drink it straight, but it was worth it. It really made me appreciate just how much sugar is dissolved in that carbonated water. My intuition initially dismissed the idea since “it’s a liquid! Goes right through me!” My case is anecdotal, but I have to admit it showed me that simply switching from regular to diet cola can be more beneficial than expected.

    On the artificial/natural thing, I vaguely remember something about substituting juice for cola not being as beneficial in terms of weight loss as some people expect. I’m quite sure juice is better in terms of vitamins, minerals, and such to make juice a pretty healthy drink, but manufacturing sugar is one of those things plants do. Fruiting plants in particular do it to attract hungry animals so they can spread the seeds. The sweeter their fruit, the more attractive they are, so they spread more seeds that also make sweeter fruit. Then humans come along and breed them to be even sweeter.

  10. locutusbrg says:

    I have seen it making the rounds in facebook which has become woo central distribution.

  11. These sweeteners may not be harmful to the end consumer. but I’m not so sure they’re very good for the workers at the manufacturing plant and the surrounding environment.

  12. locutusbrg says:

    @ kerry
    Why would it be dangerous to manufacture?
    Any food could be dangerous to manufacture without proper safety and personal protective equipment.
    What about manufacturing it is dangerous to the surrounding environment?

  13. TheFlyingPig says:

    About 2.5 years ago, the user c0nc0rdance put up a video about artificial sweeteners on youtube. It remains my go-to video on the topic; it’s very well done.

    I did recently have this Splenda post go through my Facebook feed. Someone responded to it with a link from Snopes debunking it. The response to the debunking was along the lines of “oh well, better safe than sorry. Natural is safe. If I go with natural, I don’t have to worry/think about it.” I got a similar response on Facebook when I challenged some anti-vax woo (I *always* challenge anti-vax stuff because I think it’s the most harmful pseudoscience out there right now). When the person lamented the lack of reliable information on vaccines, I sent them to SBM (in two separate posts); but I doubt they even clicked the links. A common thread I’ve noticed is that while I try to start with the scientific consensus and require a lot of evidence to reject it, others seem to give no weight to it whatsoever.


  14. DavidCT says:

    OK the artificial sweeteners are really dangerous. That is until you compare then to the all natural sweeteners. Take Honey for example. That all natural stuff is mostly fructose. In fact it is more concentrated than the “known killer” – High Fructose Corn Syrup. Then there is sucrose – white, brown, raw or refined. Once in the gut it becomes 50% fructose before absorbed. That is just between the standard 46% and 55% fructose in the most common HFCS. You are dead once again. Then there is fruit -all natural maybe even organic. That stuff breaks down to lots of methanol and formaldehyde. I guess you are stuck with Kale smoothies. Will you live longer? It will surely feel that way.

    I will let others live in fear. Moderation seems to have worked for me. I have finally reached an age where dying young is no longer an option. Cheers.

  15. ChrisH says:

    Kawarthajon: “tmac57: Yeah, but honey is all natural, so it’s naturally healthier than “artificial sweetners”, ”

    Oh, really? A few years ago some Brooklyn bee keepers had very red surprise. 🙂

    Bronze Dog: “I remember a scene from Rocko’s Modern Life where a woman orders an absurd number of snacks at a theater concession stand, “…and a diet soda. Gotta watch my girlish figure, after all.” ”

    Oh, wow. The local university is tearing down old dorms to build new ones, and invited those who had lived in them to an open house before SWAT team and fire department starting some training in them before they were torn down.

    While I did relate to other the happy memory of meeting my husband there, along with burning my horrible chemistry book in its fireplace… I did remember a terrible horrible sight I saw in the restroom near the cafeteria. That was where a friend and I discovered a toilet full of chicken bones, meat, veggie matter and actual blood. We ran to the front desk to tell them that there was a very very sick young lady in the dorm. It turned out the young lady was actually sitting calmly in the restroom with a bag of cookies. It was our introduction to bulimia.

    As the school year ran on, she actually tried to convince other eighteen to twenty year old women that it was a great way to diet!

  16. Kawarthajon says:


    Dammit! Now all the bees are going to die of cancer too! Wait a second, maybe that why bee colonies are collapsing all over the continent – they’ve turned to artificial sweeteners and it’s killing them in droves, or hives, or whatever.

  17. @Steven Novella

    Unfortunately your article misses the point entirely. The issue is not that a crank makes a fuss. The world will always be full of cranks making noises. The real issue is this —

    “…you can find studies that purport to show scary things about just about anything. There are tens of thousands of studies published every year, most of which are preliminary, with varying results. It just takes a bit of searching to find studies to support whatever view you wish.”

    Or in other words, glossing over the fact that the tonnes of garbage quality science (most of it?) gets published in journals each year.

  18. Bruce says:

    I am not sure it is Steve who missing the point, Will.

    I do look forward to your upcoming blog on “Only Science that is Useful to the Human Race, as deemed by me, Will Nitpicks”.

    Also, this is something Steve has picked up on before, if you use the little search box on the top right of the page you might have found:


    There may be others, but I guess it would be a waste of your precious posting time to actually look for anything.

  19. Martin Lewitt says:

    The association of glucose and fructose with glycation and oxidative stress is well established in the literature. When I encountered attempts at a rational defense of low carb diets, I found that they were difficult to refute. It turned out that most studies demonizing saturated fats and/or low carb diets, didn’t control for Calories and weren’t really low carb at the level being advocated, respectively. So I went looking for exactly what mechanisms accounted for the toxicity of poorly controlled glucose levels. How does high blood sugar destroy kidneys, and cause neuropathy and loss of limbs? It turns out there are very good reasons we have evolved to tightly control levels of this valuable but toxic substance, and that fructose is an even more toxic substitute.

  20. BillyJoe7 says:

    How many “nitschkes” are there between the point Steven Novella is making and the point that should be made?

  21. Four Nitschkes plus three Cannotsay’s

  22. @locutusbrg

    From wikipedia:
    “It is manufactured by the selective chlorination of sucrose (table sugar), which substitutes three of the hydroxyl groups with chlorine. This chlorination is achieved by selective protection of the primary alcohol groups followed by acetylation and then deprotection of the primary alcohol groups. Following an induced acetyl migration on one of the hydroxyl groups, the partially acetylated sugar is then chlorinated with a chlorinating agent such as phosphorus oxychloride, followed by removal of the acetyl groups to give sucralose.”

    Seeing as much of the worlds sucralose is produced in Singapore, I don’t imagine they use the latest state-of-the-art safety equipment for either the workers or the environment.

  23. atorbellino says:

    Hi, I am currently studying nutrition science and I have found that there is a lot of misinformation on the web that can lead to confusion or distrust, specially when it comes to artificial sweeteners. Actually today I found a study published by the Journal of Toxicology and Environmental Health called “SUCRALOSE, A SYNTHETIC ORGANOCHLORINE SWEETENER: OVERVIEW OF BIOLOGICAL ISSUES” which states: “cooking with sucralose at high temperatures was reported to generate chloropropanols, a potentially toxic class of compounds”.

    So after reading that study and the information above, I am confused. This is the first time for me visiting this blog and I am not a Mercola follower (never heard of him until today), but the study and this blog (it seems) are based on scientific evidence and now I don’t know which information is correct.

    The study is available here http://www.tandfonline.com/doi/abs/10.1080/10937404.2013.842523#.UuhP1Pnn_IV

    Can you tell me your thoughts on this?

    Thank you in advance.

  24. pdeboer says:

    I’m a frequent drinker of caffeine free diet Coke ( I do not work for them though ). Whenever the harm of aspartame comes up I have my standard response about the brain lesions/tumors accusation. The studies that show that aspartame can cause lesions in the brain are done in rats. When performed on primates it has no effect, likely because we have a mechanism to prevent the amino acid from crossing the blood brain bridge.

    However, I never had a response to the claim that it can cause diabetes because your body responds to the non-nutritive sweetener as if it is sugar.

    My response was generally that I am skeptical that our brain is in control of our insulin by our opinion of taste.

    Thanks Steve for making me finally find a response to this claim. I found a review blog that went through the popular sweeteners and linked to several studies showing no insulin change from consuming splenda, sweet n low or aspartame.

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