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Artificial sweeteners linked to glucose intolerance

412 points by bensedat 12y ago

raverbashing 12y ago
This raises more questions than it answers I think (which is a good thing) 1 - Is there such thing as a "sweet base"? Our tongues perceive sweeteners as sweet (duh) but it seems it mimics sugar in a way for bacteria as well. 2 - From the article "Wiping out the rodents' gut bacteria using antibiotics abolished all the effects of glucose intolerance in the mice. In other words, no bacteria, no problem regulating glucose levels." Soooo... Bacteria affects absorption of glucose? They consume it? They change the intestinal PH? Or something else?
jimhefferon 12y ago
Diet soda makes you fat.
themgt 12y ago
I'd be curious if they tried this study with xylitol. I chew xylitol gum for dental health and from my understanding it's not thought to contribute to metabolic problems in reasonable quantities: http://en.wikipedia.org/wiki/Xylitol#Diabetes http://en.wikipedia.org/wiki/Xylitol#Diabetes
- sp332 12y ago
  From the caption on one of the figures (which is all I can access without buying the article) "NAS; saccharin, sucralose and aspartame". So I don't think they tried xylitol.
- 001sky 12y ago
  "from my understanding it's not thought to contribute to metabolic problems in reasonable quantities" Xylitol is quite toxic to some animals, such as dogs tho. http://www.vcahospitals.com/main/pet-health-information/article/animal-health/xylitol-toxicity-in-dogs/4340 http://www.vcahospitals.com/main/pet-health-information/arti... edit: this snippet maybe worth highlighting In both humans and dogs, the level of blood sugar is controlled by the release of insulin from the pancreas. Xylitol does not stimulate the release of insulin from the pancreas in humans. However, when non-primate species (e.g., a dog) eat something containing xylitol, the xylitol is quickly absorbed into the bloodstream, resulting in a potent release of insulin from the pancreas. This rapid release of insulin results in a rapid and profound decrease in the level of blood sugar (hypoglycemia), an effect that occurs within 10-60 minutes of eating the xylitol. Untreated, this [canine] hypoglycemia can be life-threatening.
  - jerf 12y ago
    That doesn't help much, though. There's all kinds of things that are toxic to one species and not another, even just in Mammalia, and everything that anything anywhere ever eats is definitely not good for some other species.
    - 001sky 12y ago
      The mechanism of toxicity (in dogs) is specifically relevant. There are multiple studies showing that artificial sweeteners in general are unhealty -- the body recognizes them -- and takes a variety of actions as a result. Clearly these reactions in some cases may be simply performance related (see: http://www.gssiweb.org/Article/sse-118-carbohydrate-mouth-rinse-performance-effects-and-mechanisms http://www.gssiweb.org/Article/sse-118-carbohydrate-mouth-ri...). Whilst others can be catastrophic (see: xylitol in dogs).
- erickhill 12y ago
  Agreed, or stevia (which is found in some high-priced colas, among other products). http://en.wikipedia.org/wiki/Stevia http://en.wikipedia.org/wiki/Stevia
- whyenot 12y ago
  Xylitol was not included in the study. Because xylitol is absorbed more slowly from the gut and gut microflora appear to be the mechanism of action found in this study, I'd personally be at least a little concerned. Mice in this study were given sweeteners for 11 weeks, long enough that their use apparently led to changes in microflora which were associated with glucose intolerance. Existing studies of xylitol could well be for much shorter lengths of time and might not have been able to detect these kinds of changes.
  - yupmetoo 12y ago
    I wonder then if its the absorption of the gut or if it is the conditioning. If the gut flora have to adapt to trying to break down an impenetrable compound they might become super strong at breaking down simpler molecules no?
coldcode 12y ago
People rarely consider how what you eat affects your microflora which then affects various other systems and may even affect your desire to consume.
- at-fates-hands 12y ago
  This is the same thing with having good oral hygiene. So many serious health problems can be traced back to poor oral hygiene. If you go nothing else, make sure you take good care of your mouth, gums and teeth!
  - deleted 12y ago
    [deleted]
- viewer5 12y ago
  Without delving into a bunch of scientific papers, how could I go about considering how my dietary choices influence my microflora for better or worse?
  - tormeh 12y ago
    Well, you can't really do that. We don't know nearly enough about it. Hell, we're not even good at normal dietary science yet and the whole gut bacteria science field is really new. You can find a healthy and fit person and get them to give you some of their gut flora and then eat it. That could probably work. It also might make you sick (I imagine) and it's terribly disgusting: "On a scale from swallowed to poo, how do you want my eaten food?"
    - dasil003 12y ago
      I don't think that would work (bacteria living the colon can not necessarily survive all the way through the digestive tract). What is an accepted form of gut biome therapy is a stool transplant: http://en.wikipedia.org/wiki/Fecal_bacteriotherapy http://en.wikipedia.org/wiki/Fecal_bacteriotherapy
Dirlewanger 12y ago
"metabolic abnormalities" Anyone know if they go into these into the paper? Really want to know what else is in the paper; I chew way too much sugar-free gum.
- e40 12y ago
  I chew way too much sugar-free gum. At first I thought, yeah, this will never be a problem for me, then I realized the only thing I do consume with artificial sweeteners is gum. I do hope the doses are low enough not to be a problem, but I want to know!
- driverdan 12y ago
  Based on the doses they used you'd have to chew multiple packs of gum per day to get the same amount of sweetener.
- spmurrayzzz 12y ago
  Most sugar-free gum uses some type of sugar alcohol (e.g. xylitol, erythritol). These are not technically-speaking considering NAS. Their mechanisms of absorption vary wildly and, while in some cases they can cause digestive stress in large amounts, there is no good evidence AFAIK that they have a deleterious effect on gut microbiota.
SCHiM 12y ago
Can anybody explain or guess what the consequences of this intolerance are or could be?
- pyre 12y ago
  It's a pre-diabetic state: http://www.diabetes.co.uk/glucose-intolerance.html http://www.diabetes.co.uk/glucose-intolerance.html
- ddebernardy 12y ago
  You might find this video on fructose and metabolic disease (of which glucose intolerance is a symptom) interesting: http://www.youtube.com/watch?v=dBnniua6-oM http://www.youtube.com/watch?v=dBnniua6-oM
  - pyre 12y ago
    It's worth noting that there are many critics of this guy.
    - ddebernardy 12y ago
      True. As I understood them though, the criticism was primarily about his message that fructose would be the key or only reason of metabolic syndrome, or his depiction of sugar as pure evil rather than as something which you can consume in small amounts, more than about the effects of fructose itself. (When not, connections between the critic and the sugar or food industry were quick to Google, thereby reducing the credibility to zero.) This may have changed since I spent time digging into it, though, so please expand if it has.
      - pyre 12y ago
        My point was just to point out that criticism exists. Loads of people watch that video and don't do other research on the topic.
nostromo 12y ago
Here's a nice write up about the results: http://www.newscientist.com/article/mg22329872.600-artificial-sweeteners-linked-to-glucose-intolerance.html http://www.newscientist.com/article/mg22329872.600-artificia... Note that the mice were given the human equivalent of 18 to 19 cans of diet soda a day.
- dang 12y ago
  Thanks. We changed the url to that from http://www.nature.com/nature/journal/vaop/ncurrent/full/nature13793.html http://www.nature.com/nature/journal/vaop/ncurrent/full/natu... because the paper is paywalled. There is also http://www.economist.com/news/science-and-technology/21613311-sugar-substitutes-may-mess-gut-bacteriacausing-obesity http://www.economist.com/news/science-and-technology/2161331..., via https://news.ycombinator.com/item?id=8331143 https://news.ycombinator.com/item?id=8331143.
- kazinator 12y ago
  This write up also only implicates saccharin in the harmful alterations of the gut flora, not other sweeteners. Yet the introductory text talks about artificial sweeteners are a group. You cannot confirm the effects of "artificial sweeteners" as a category with an experiment that is based on saccharin. They are all different molecules. A bacterium that thrives on saccharin might not consume sucralose or aspartame. Also glaringly absent is any mention of the sugar alcohols: sorbitol, xylitol, maltitol. Who cares about saccharin. It is an outdated sweetener which is not widely used. Where can you find a diet soft drink or protein bar sweetened with saccharin?
  - randallsquared 12y ago
    First, I care, since saccharin is (was?) my preferred sweetener, for coffee, etc. Second, saccharin is very widely available at restaurants and so forth, coming in a very close second to aspartame, in my experience.
    - kazinator 12y ago
      I know that it's available if you want it; but then, so are alcohol and cigarettes. If a study could link popular, widely-deployed sweeteners found in processed foods and drinks, that would point to a big public health issue. A problem with saccharin doesn't point to a wide-spread public health issue. Sacharrin has been vilified on and off over its entire lifetime. My parents' and grandparents' generation believed that it was a harmful poison, for instance; I remember hearing that as a kid. Only in the year 2000, in the US, were requirements for warning labels lifted, which had been in the effect since the 1970's, when saccharin was linked to cancer in rodents: http://en.wikipedia.org/wiki/Saccharin#Warning_label_addition_and_removal http://en.wikipedia.org/wiki/Saccharin#Warning_label_additio... In spite of the lift, it doesn't seem that saccharin has made a comeback. Part of the reason could be taste. Particular mixtures of sweeteners are used in diet foods sweeteners in order to better simulate the taste of sugar.
sadfaceunread 12y ago
This is an impressive piece of work but I worry that a larger amount of work is needed in the relationship between glucose intolerance, diabetes and metabolic syndromes in general. The fact that glucose intolerance is induced by a high sugar diet and leads towards a path of clinical outcomes ending in diabetes, doesn't necessarily indicate that glucose intolerance developed via artificial sweetener consumption is indicative of being on the same clinical pathways towards metabolic syndrome and diabetes.
sp332 12y ago
Does this mean diabetes could (in some cases) be caused by gut bacteria? Can we reduce diabetes risk factors with targeted antibiotics that attack certain glucose-intolerance-causing bacteria?
- jonnathanson 12y ago
  It's fiendishly difficult to pry apart correlation and causation for complex conditions like diabetes (which we're steadily reconceptualizing as less of a "disease," and more of a chain reaction of metabolic and hormonal disorders). Changes in gut bacteria are associated with the condition sometimes called "pre-diabetes," or a "pre-diabetic state." But we're not yet sure if they are a causative factor, if they are the result of the condition, or if they're simply co-morbid with it. Whatever the case, gut bacteria appear to play a vital role in our metabolic health, and we're only beginning to explore this area in earnest.
- cauterized 12y ago
  There's also some indication from other studies that antibiotics killing off symbiotic gut flora may be implicated in diabetes.
- UrMomReadsHN 12y ago
  Yes, absolutely possible. There is so much potential in gut bacteria research and we are only starting to recently scratch the surface with it. I get really excited about the topic of gut bacteria for some reason, it is just very interesting. Its hard to separate cause and effect right now though. There also may be a snowball effect. We just know so little so there is a lot of research that needs to be done. Antibiotics are unlikely. Fecal transparents are much more likely. Fecal transparents are starting to be used for c. Diff infections with success.
Someone1234 12y ago
So the public funds studies, which they give to journals for free, who then sell access for $3.99/view. I'm really not sure this was the "free exchange of ideas" which science is based upon. Even the New York times only charges $3.75/week (the nature price is per article/view NOT per week, it would be $4.14 if their $199 plan was weekly) and the NYT has to actually pay journalists to create the content. Nature gets all their content for free. So what are Nature's expenses anyway? They no longer have to type set as it is just an identical PDF which is sent to them. Is hosting and management of the web-site really so costly that it is $3.99/article?
- Swizec 12y ago
  > So what are Nature's expenses anyway? The prestige. (theoretically that means organising the peer review part of science and such)
  - AUmrysh 12y ago
    Nature has the highest impact factor of any research journal. They can basically ask for whatever they want at this point, because someone out there will be willing to pay it to get their paper in nature.
- yincrash 12y ago
  The peer review process, I would think.
  - Someone1234 12y ago
    They don't pay for people to peer review as far as I know.
    - dragonwriter 12y ago
      That the individual peer reviewers aren't paid does not imply that coordinating the peer review process is cost-free to the publication.
  - 12y ago
WesleyRourke 12y ago
Raised insulin levels are much more complicated than we once thought. You can get an insulin response from artificial sweeteners just swished in your mouth and spat out. Solution, eat real food when you can
- 3rd3 12y ago
  Do you have a source for that? The last time I checked this worked with mice, but humans showed no insulin response from sweet taste alone.
  - BSousa 12y ago
    I don't right now, but from my times when competing, I used to read a lot of science based research on nutrition and there was a study that said swishing a carb rich liquid was enough to trigger it. I think I first saw it referenced on an old edition of 'The Complete Guide to Sports Nutrition' by Anita Bean
    - demallien 12y ago
      Artificial sweeteners are not "carb rich". That's kind of the point of them...
      - BSousa 12y ago
        What I meant was there is a possibility of it happening as a sweet taste (parent didn't mention sweeteners, just sweet taste) response since there is a similar response to carb rich drinks (study didn't mention the kind of carbs so no idea)
    - spmurrayzzz 12y ago
      Are you referring to the salivary amylase mechanism? Sounds similar but actually requires starch to be activated. I'm aware of no RCT or even epidemiological research to suggest that NAS causally mediates insulin response.
  - 12y ago
jimrandomh 12y ago
The headline is suspicious, but unfortunately, this article is paywalled, so I can't tell what's really going on. The main problem with the headline is that it lumps together "artificial sweeteners" as a category, when that is in fact a pretty widely varied class of molecules.
- glaugh 12y ago
  Agreed. From the article Nostromo just posted[1], looks like the mouse models were based on aspartame, saccharin, and sucralose, and the human subjects were taking saccharin. [1] http://www.newscientist.com/article/mg22329872.600-artificial-sweeteners-linked-to-glucose-intolerance.html#.VBnjFWRdX4K http://www.newscientist.com/article/mg22329872.600-artificia...
FranOntanaya 12y ago
Do they compare pure sweetener diet with pure sugar diet calorie per calorie, and sweetness units per sweetness units? Sweeteners are still caloric, the point is that they provide the same sweetness for less calories.
mcmancini 12y ago
Overall, this was a nicely done study. The microbiome is fascinating and an exciting area of research. One criticism however would be that the dose of artificial sweetener tested was atypically high. It'll be neat to see further research into the cause of variable responses of the subjects to the artificial sweeteners.
- cschmidt 12y ago
  According to the New Scientist article others have linked to, the equivalent human dose was 9-12 packets of sweetener a day. I'm sure there are heavy coffee drinkers that go through that much. I also don't like those studies where the human equivalent dose is like 50 pounds of sweetener a day, or something silly. This one isn't so bad.
  - whyenot 12y ago
    For comparison, that amount of sweetener (9-12 packets) is found in about 3 cans of Diet Coke (35mg aspartame per packet, 125mg per Diet Coke). I suspect there are quite a few people who consume more than that in a day.
  - mcmancini 12y ago
    I guess I'm having trouble figuring out where the numbers are coming from. I'm seeing that the FDA recommended maximum dose for aspartame is 50mg/kg/day. Assuming a 70kg Standard Man, that's 3.5g/day of aspartame. Diet Coke has 125mg per 12oz. can, so that would be 28 cans/day. Each packet should be around 35mg aspartame, so 100 packets/day (the amount of aspartame per packet was hard to find, and the approx. was from an American Cancer Society article). Agreed that 9–12 packets doesn't sound like much, but I think we're talking way more than that.
    - deleted 12y ago
      [deleted]
kazinator 12y ago
This seems misleading. If you go through the graphs and results, what emerges is that only the sweetener saccharin has that altering effect on the gut bacteria. I cannot find among the results any claim that the other NAS that were studied (sucralose and aspartame) have the effect. The thing is that saccharin is not widely used any more. If saccharin is found to be harmful, that is nice to know, but not highly relevant.
tokenadult 12y ago
I'm paywalled out of seeing the whole article until I try a workaround (after which I may expand this comment), but I think we can all see the abstract of the article if we follow the link kindly submitted here. Yet some questions in other comments raise issues that are already responded to by the article abstract. Here is the full text of the article abstract available in the free view at the link: "Non-caloric artificial sweeteners (NAS) are among the most widely used food additives worldwide, regularly consumed by lean and obese individuals alike. NAS consumption is considered safe and beneficial owing to their low caloric content, yet supporting scientific data remain sparse and controversial. Here we demonstrate that consumption of commonly used NAS formulations drives the development of glucose intolerance through induction of compositional and functional alterations to the intestinal microbiota. These NAS-mediated deleterious metabolic effects are abrogated by antibiotic treatment, and are fully transferrable to germ-free mice upon faecal transplantation of microbiota configurations from NAS-consuming mice, or of microbiota anaerobically incubated in the presence of NAS. We identify NAS-altered microbial metabolic pathways that are linked to host susceptibility to metabolic disease, and demonstrate similar NAS-induced dysbiosis and glucose intolerance in healthy human subjects. Collectively, our results link NAS consumption, dysbiosis and metabolic abnormalities, thereby calling for a reassessment of massive NAS usage." AFTER EDIT: After reading all the comments in this thread to the time of this edit, I see that some participants here disagree entirely with how I commented at first (as above). I note their opinion with interest and say here for the record simply that I saw previous comments that raised questions about information that is available in the article abstract for all of us to read. I meanwhile did find my workaround to get the full text of the article (I have library access with journal subscriptions for one aspect of my work, which is rather slow and buggy) and from the full article text I see that the experimental approach the researchers tried--feeding mice with the artificial sweetener to see if that changed gut microbiota in the mice, and then transferring the gut microbiota to other mice--did indeed bring about clinical signs consistent with the idea that the sweetener itself might cause related clinical signs in human beings. "To test whether the microbiota role is causal, we performed faecal transplantation experiments, by transferring the microbiota configuration from mice on normal-chow diet drinking commercial saccharin or glucose (control) into normal-chow-consuming germ-free mice (Extended Data Fig. 1e). Notably, recipients of microbiota from mice consuming commercial saccharin exhibited impaired glucose tolerance as compared to control (glucose) microbiota recipients, determined 6 days following transfer (P < 0.03, Fig. 1e and Extended Data Fig. 2e). Transferring the microbiota composition of HFD-consuming mice drinking water or pure saccharin replicated the glucose intolerance phenotype (P < 0.004, Fig. 1f and Extended Data Fig. 2f). Together, these results establish that the metabolic derangements induced by NAS consumption are mediated by the intestinal microbiota." This preliminary finding, which of course needs to be replicated, has caused alarm in the industry, according to the link participant nostromo kindly shared in this thread.[1] There is epidemiological signal that human beings who consume a lot of artificial sweeteners are not especially healthy people compared to people who consume few. Teasing out the mechanism that may underly that observational finding will take more research, but this is important research to get right. "To study the functional consequences of NAS consumption, we performed shotgun metagenomic sequencing of faecal samples from before and after 11 weeks of commercial saccharin consumption, compared to control mice consuming either glucose or water. To compare relative species abundance, we mapped sequencing reads to the human microbiome project reference genome database16. In agreement with the 16S rRNA analysis, saccharin treatment induced the largest changes in microbial relative species abundance (Fig. 2a, Supplementary Table 2; F-test P value < 10−10). These changes are unlikely to be an artefact of horizontal gene transfer or poorly covered genomes, because changes in relative abundance were observed across much of the length of the bacterial genomes, as exemplified by one overrepresented (Bacteroides vulgatus, Extended Data Fig. 7a) and one underrepresented species (Akkermansia muciniphila, Extended Data Fig. 7b)." The authors sum up their experimental findings by writing "In summary, our results suggest that NAS consumption in both mice and humans enhances the risk of glucose intolerance and that these adverse metabolic effects are mediated by modulation of the composition and function of the microbiota. Notably, several of the bacterial taxa that changed following NAS consumption were previously associated with type 2 diabetes in humans13, 20, including over-representation of Bacteroides and under-representation of Clostridiales. Both Gram-positive and Gram-negative taxa contributed to the NAS-induced phenotype (Fig. 1a, b) and were enriched for glycan degradation pathways (Extended Data Fig. 6), previously linked to enhanced energy harvest (Fig. 2c, d)11, 24. This suggests that elaborate inter-species microbial cooperation may functionally orchestrate the gut ecosystem and contribute to vital community activities in diverging environmental conditions (for example, normal-chow versus high-fat dietary conditions). In addition, we show that metagenomes of saccharin-consuming mice are enriched with multiple additional pathways previously shown to associate with diabetes mellitus23 or obesity11 in mice and humans, including sphingolipid metabolism and lipopolysaccharide biosynthesis25." There have been a lot of questions raised in this thread, and indeed the article itself raises plenty of interesting questions to follow up with further research. When discussing a new preliminary research finding like this, we can work outward from the article abstract to news reports about the article findings to the article text itself to focus on the known issues and define clearly the unknown issues. I appreciate comments from anyone here about how I can help contribute to more informed and thoughtful, in Hacker News sense of "thoughtful,"[2] discussion of research on human nutrition. Other comments here asked why we should respect journal paywalls at all, and the basic answer to that question is a basic principle of economics, that people respond to incentives. (That's the same reason you don't found a startup that you expect will always lose money for all time.) Nature is one of the most-cited scientific journals in the world, so it's a big coup to be published there, and that means Nature gets a lot of submissions. To slog through all the submissions with adequate editorial work does cost money. (I used to be a junior editor of an academic journal.) The article gets more attention (it has received a lot of attention in this thread) if it is in a better rather than worse journal. Some journals are lousy enough to publish anything, and those journals beg for submissions, but Nature can charge for subscriptions and impose paywalls (which expire for government-funded research, with author sharing of author manuscripts on free sites usually being mandatory after a year embargo) because what it publishes is often worth reading (as here). AFTER ONE MORE EDIT: I see that while I was reading the fine article from Nature submitted to open a thread, my comment is now part of a thread that is about the New Scientist popular article on the same research finding. This will be confusing to readers newly visiting this thread. The title of the Nature article is "Artificial sweeteners induce glucose intolerance by altering the gut microbiota" (the Hacker News thread title I saw, per the usual rule of using the article headline as the submission headline) and the article DOI is 10.1038/nature13793 for the full article published online (behind a paywall) on 17 September 2014. [1] http://www.newscientist.com/article/mg22329872.600-artificial-sweeteners-linked-to-glucose-intolerance.html http://www.newscientist.com/article/mg22329872.600-artificia... [2] "The most important principle on HN, though, is to make thoughtful comments. Thoughtful in both senses: both civil and substantial." https://news.ycombinator.com/newswelcome.html https://news.ycombinator.com/newswelcome.html
mladenkovacevic 12y ago
I hope this doesn't hold true for stevia as well :/
- medell 12y ago
  Pure stevia is not artificial, but the verdict is still out on safety. It seems to be OK... for now. I use it, though I try to use honey as well.
  - UrMomReadsHN 12y ago
    The stevia whole leaf has been used for centuries in teas on Brazil. It has been used as an artificial sweetener in Japan for decades accounting for around 40% of the sweetener market there. Weirdly, I always bought it labeled as a dietary supplement in the US before the FDA approved some extracts as food additives.
  - UrMomReadsHN 12y ago
    The stevia whole leaf has been used for centuries in teas on Brazil. It has been used as an artificial sweetener in Japan for decades accounting for around 40% of the sweetener market there. Weirdly, I always bought it labeled as a dietary supplement in the US before the FDA approved some extracts as food additives.
- cmapes 12y ago
  That was my first thought too, I use stevia in almost everything.
driverdan 12y ago
Can someone post the full paper? The charts shown at the bottom seem to contradict some of their conclusions and implications. For example, some of the sweeteners seemed to result in lower chow consumption and increased energy expenditure. That would be a positive effect that isn't mentioned in the abstract.
oomkiller 12y ago
This seems very misleading. The abstract (available without paywall) mentions a group of sweeteners, whereas the findings seem to show that only saccharin has these negative effects. I feel like NAS are probably bad, but without evidence to support it they should not claim that in the abstract.
lee 12y ago
So given a choice, between Diet Soda vs. Normal Soda, what would be worse for your overall health? I imagine even with increased glucose intolerance, you're still better off choosing Diet?
- Wingman4l7 12y ago
  Depends on how much you're consuming.
- _greim_ 12y ago
  Not a direct answer, but noting that there's also a third choice, which is to not drink anything sweet. I'll chug a diet soda once in a while because what's the downside? But in light of new compelling evidence I might change that habit without too much fuss.
- dragonwriter 12y ago
  You're probably better off not choosing carbonated liquid candy -- especially not doing so regularly and in significant quantities -- even if the sweetener happens to be non-caloric. And the point where you've reduced your choices to regular soda vs. diet soda, you've already failed.
  - tedunangst 12y ago
    Failed at what?
    - marcosdumay 12y ago
      Failed at having a healthy diet. (That is, if he does make that choice frequently - a one time event probably won't change anything.)
      - parasubvert 12y ago
        In what way is it unhealthy? Aspartame has zero calories, and decades of studies showing its safety. Put another way, if you want to avoid sugar (which is much less healthy than aspartame), besides water, there's tea, coffee, flavoring mixes like Crystal Light, and various prepared sugar free soft drinks. Many prefer variety over water. There's little scientific basis to believe drinking any of these things are bad. Drinking a mix of these is quite a bit healthier for an adult than chugging juice or sugared drinks - unless you're explicilty trying to carb-load. Milk is a healthy alternative but debatable due to its effects on some.
kolev 12y ago
Sweeteners are suspected to have downed the Roman empire (via lead poisoning), so, learn from history and just change your taste norm and you'll live longer and happier. I had a sweet tooth once and it took about a couple of years to even not being able to tolerate it. The weak find excuses, the strong adapt and improve. Just reject anything with refined sugar or fancy new "healthier" sweeteners - do you like sugar more than tomorrow? Cane sugar is not healthier than HCFS (it might be just slightly less harmful). Agave "Nectar" actually has significantly more fructose than HCFS... and it's not unprocessed as claimed, and so on. Stevia is slightly different, the plant has other benefits, but I wouldn't ever use the adulterated version (Reb A or whatever). Hack your taste buds, hackers!
- kolev 12y ago
  Sugar alcohols (xylitol, sorbitol, maltitol, mannitol, erythritol) have the same negative effect on the gut microbiota.
mratzloff 12y ago
FDA acceptable daily intake (ADI) for aspartame is 50 mg per kg of body mass.[0] For an individual 180 pounds, that's about 82 kg. That means his ADI is 4100 mg. Aspartame in popular diet sodas is between 50 and 125 mg.[1] You'd have to drink A LOT of diet soda to reach these levels. [0] http://www.cancer.org/cancer/cancercauses/othercarcinogens/athome/aspartame http://www.cancer.org/cancer/cancercauses/othercarcinogens/a... [1] http://static.diabetesselfmanagement.com/pdfs/DSM0310_012.pdf http://static.diabetesselfmanagement.com/pdfs/DSM0310_012.pd...
- lucaspiller 12y ago
  I have a friend who used to drink nothing but Diet Coke. He went through a few 2l bottles a day. According to that link (assuming it's the same in Europe), Diet Coke is 125mg per 8 ounces, so a 2l bottle is 125 / 8 x 70.4 = 1100mg. So if he drank four 2l bottles, that's over the daily limit.
skue 12y ago
For those not aware, other studies have shown that consuming diet soda may actually increase the chance of obesity. So that is not necessarily news. If you are curious, here is a pretty good study (full text): http://onlinelibrary.wiley.com/doi/10.1038/oby.2008.284/full http://onlinelibrary.wiley.com/doi/10.1038/oby.2008.284/full More recently, studies have tried to determine whether there is a satiety or protein mechanism that can explain this, whereas this new study demonstrates that gut flora may play a role. This needs to be confirmed, and there may still be other mechanisms at play as well, but it is interesting. (Disclaimer: I do have a healthcare background, but am not a researcher in this field. Would be happy to hear more from anyone who is.)
- Istof 12y ago
  I keep drinking diet soda and I still can't gain weight (news: big eaters get fat)
- jonnathanson 12y ago
  Indeed. I think it helps to unpack the various claims being studied: 1) Carcinogenicity. Do certain sweeteners cause harmful mutations and increase cancer risk? This is one of the oldest and most frequent allegations, especially against saccharin and aspartame. Mostly inconclusive, though both sweeteners have been exonerated at least as often as they've been accused. 2) Insulin triggering. Artificial sweeteners may not bear the caloric load of sugars and starches -- but do they trigger the release of insulin, just the same? Again, the jury is still out, but certain sweeteners (aspartame, sucralose, and possibly saccharin) are looking suspect. 3) Caloric load. Some sweeteners and putatively indigestible molecules (sugar alcohols, "resistant starches," etc.) may contain more effective calories than in vitro studies predict them to contain. This is because the chemicals aren't digested in the traditional sense, but are fermented and absorbed in the gut. Caloric bioavailability is often different from nominal calorie count. (Indeed, this is the entire principle behind the supposed benefits of resistant sweeteners and starches; those benefits may have been overstated or misunderstood). 4) Disruption or adverse selection of gut microbiota. As detailed in this study. While not all sweeteners have been implicated here, this field of study is only just kicking into high gear. It seems reasonable to suspect that molecules fermented by / consumed by gut bacteria could have some effect on flora composition. Many sweeteners fit that criterion. 5) Other toxicities. Liver or kidney toxicity, neurotoxicity, endocrine disruption, etc. As with carcinogenicity, the jury is still out. Unlikely for some sweeteners that are not metabolized via these pathways. Possible for others. Most sweeteners (all?) on the market right now are generally recognized as safe in this respect, despite popular beliefs to the contrary. Notable exceptions exist for those with rare metabolic or genetic disorders, such as phenylketonuria (aspartame contains phenylalanine). 6) Side effects. Some sweeteners, particularly those in the sugar alcohol family (and sorbitol especially), can cause laxative effects and other GI-related issues. Individual tolerance can vary. Breaking this category out from #4 because the action here can be purely mechanical (i.e., increasing intestinal water absorption). I'm not a doctor or medical researcher myself. Just an interested nerd. But I have been following this area for awhile. I welcome any corrections, comments, or additions from people more knowledgeable than I am. I assume there are many such people on HN. :)
blackbagboys 12y ago
The New Scientist article notes that four of the seven human subjects who consumed three to four sachets of sweetener a day saw a significant change in their gut bacteria. As someone who has consumed significantly more than that for a very long time, my question would be, did their gut flora reconstitute itself after they stopped using the sweetener? And if not, how could you go about repopulating your microbiome short of a stool sample?
- BadCookie 12y ago
  A probiotic might help. A gastroenterologist once recommended Align to me, if that's helpful to you.
- uladzislau 12y ago
  The gut flora is as resilient as any other part of human body. It might take a significant time though. I've heard Korean food helps a lot because it's fermented. Also usual bifido youghurts you'll find at any grocery store.
- acomjean 12y ago
  The does in the article is higher than your post: 3-4 sachets taken 3 times a day. Those packets to me are sweet. I alternate between honey and half a packet in my tea. Gut Flora do come back (eg after taking antibiotics which cuts them down). They're crowded in there, so the ratio of them is important. Everyone has different ratio and there is no easy way to measure and control that.
kens 12y ago
This result seems pretty strange to me - why would artificial sweeteners affect bacteria's metabolism in this way? It seems like a bizarre coincidence that bacteria would react in the same way to three different sweeteners, unless they have receptors that happen to match human taste receptors (which also seems unlikely). In other words, to bacteria these sweeteners should just seem like unrelated random chemicals. (I read the Nature paper - most of it looks at saccharin since that had the strongest response, but all three artificial sweeteners caused marked glucose intolerance.)
- joekrill 12y ago
  Well, not everything makes immediate intuitive sense.
  - dragonwriter 12y ago
    Yeah, that's pretty much the whole reason we need science.
- lnanek2 12y ago
  Bacteria are, in general, much more capable at processing various chemicals than humans are. They can even pass around packets of genetics, called plasmids, across species. So it isn't really surprising if bacteria can flourish eating something that tastes sweet to people, but doesn't provide any calories to people. There have been some artificial sweeteners shown to hurt bacteria more than people - Xylitol is famously used in gum, for example, because it costs bacteria energy to try to eat it, but they gain nothing, thus helping to fight bacteria growth.
  - calinet6 12y ago
    Aspartame is essentially just a collection of amino acids, so it's even more feasible (in a total guessing hand-wavey way) that gut bacteria would be affected.
duschang27 12y ago
Abstract can be found here. http://www.nature.com/nature/journal/vaop/ncurrent/full/nature13793.html http://www.nature.com/nature/journal/vaop/ncurrent/full/natu...
biot 12y ago
I like how all the people who benefit from artificial sweeteners are refuting something which the study doesn't claim. For example: "The International Sweeteners Association (ISA) says it strongly refutes the claims made in the study: 'There is a broad body of scientific evidence which clearly demonstrates that low-calorie sweeteners are not associated with an increased risk of obesity and diabetes as they do not have an effect on appetite, blood glucose levels or weight gain.'" It's true that artificial sweeteners have no immediate effect on appetite, blood glucose levels, nor weight gain. None of these are claims made by the study. Everyone is refuting the immediate effects of artificial sweeteners. The study claims that after consuming artificial sweeteners, if you then consume something naturally sweet, the prior consumption of an artificial sweetener alters your glucose tolerance levels. It's the equivalent of saying that removing all the trees from around rivers has no effect on fish population because clearly fish don't live in trees. But it's the secondary effects of this which such a statement ignores: the increase in soil erosion impacting water quality, change in water temperature due to having more direct sunlight, and so on. Also: "'Decades of clinical research shows that low-calorie sweeteners have been found to aid weight-control when part of an overall healthy diet, and assist with diabetes management,' says Gavin Partington of the British Soft Drinks Association." This has little meaning without having a reference point to compare the results to. If the study is correct, take one group of people who use diet soft drinks with an overall healthy diet and compare it to another group of people who consume the same overall healthy diet but drink water instead of diet soft drinks, and the group that drinks water should have a better glucose tolerance response than the diet soft drink group.
- deleted 12y ago
  [deleted]
- azakai 12y ago
  > It's true that artificial sweeteners have no immediate effect on appetite Yes, but the quote you give doesn't mention immediate effects in particular. And to the contrary, they mention things like obesity and diabetes which are not immediate effects. To me, it sounds like they are not saying what you say they are.
pistle 12y ago
The industry takeaway should be to try to isolate the bacteria that play the secondary part in the glucose resistance, then put ANOTHER additive in the drinks to kill that bacteria, then sell a more expensive NEW zero calorie drink? People like sweet. Let's make sweet safe.
louwrentius 12y ago
The maximum dose is quite high, but does the effect also occurs when consuming more sane dosage a day?
devindotcom 12y ago
Doesn't seem so strange - if you create a sugar deficit in your body by significantly reducing your intake, wouldn't you expect the body to be more responsive to sugars when it encounters them?
- mark-r 12y ago
  I believe that's why they had a control group with unsweetened water.
dbbolton 12y ago
Now let's see a human study where people who consume those sweeteners, eat carbohydrates in moderation, and exercise regularly are still at increased risk for diabetes.
voidlogic 12y ago
I'm not really surprised Saccharin isn't great for you personally- but this isn't so damning there are many other artificial sweeteners to choose from. https://en.wikipedia.org/wiki/Sugar_substitute#Artificial_sugar_substitutes https://en.wikipedia.org/wiki/Sugar_substitute#Artificial_su... I'd of course like to see them all studied in this manner.
rcthompson 12y ago
For some biological context, we have taste receptors in our digestive tracts identical or nearly identical to those on our tongue, only the ones in our digestive tract are not hooked directly to sensory neurons, but instead trigger endocrine signals and such. Since the receptors are identical, then anything that tastes sweet on your tongue will activate these receptors as well. If I recall my metabolism course correctly, studies have found that artificial sweeteners can trigger insulin release through these receptors in the same way as real sugar (leading to possible hypoglycemia as your body compensates for a rush of sugar that never comes). So basically, I have no trouble believing that artificial sweeteners can have many of the same long-term health effects as excessive consumption of real sugar, since they're already known to have many of the same short-term effects, including effects on insulin regulation.

412 points by bensedat 12y ago

This raises more questions than it answers I think (which is a good thing) 1 - Is there such thing as a "sweet base"? Our tongues perceive sweeteners as sweet (duh) but it seems it mimics sugar in a way for bacteria as well. 2 - From the article "Wiping out the rodents' gut bacteria using antibiotics abolished all the effects of glucose intolerance in the mice. In other words, no bacteria, no problem regulating glucose levels." Soooo... Bacteria affects absorption of glucose? They consume it? They change the intestinal PH? Or something else?

jimhefferon 12y ago

Diet soda makes you fat.

themgt 12y ago

I'd be curious if they tried this study with xylitol. I chew xylitol gum for dental health and from my understanding it's not thought to contribute to metabolic problems in reasonable quantities: http://en.wikipedia.org/wiki/Xylitol#Diabetes http://en.wikipedia.org/wiki/Xylitol#Diabetes

sp332 12y ago
From the caption on one of the figures (which is all I can access without buying the article) "NAS; saccharin, sucralose and aspartame". So I don't think they tried xylitol.
001sky 12y ago
"from my understanding it's not thought to contribute to metabolic problems in reasonable quantities" Xylitol is quite toxic to some animals, such as dogs tho. http://www.vcahospitals.com/main/pet-health-information/article/animal-health/xylitol-toxicity-in-dogs/4340 http://www.vcahospitals.com/main/pet-health-information/arti... edit: this snippet maybe worth highlighting In both humans and dogs, the level of blood sugar is controlled by the release of insulin from the pancreas. Xylitol does not stimulate the release of insulin from the pancreas in humans. However, when non-primate species (e.g., a dog) eat something containing xylitol, the xylitol is quickly absorbed into the bloodstream, resulting in a potent release of insulin from the pancreas. This rapid release of insulin results in a rapid and profound decrease in the level of blood sugar (hypoglycemia), an effect that occurs within 10-60 minutes of eating the xylitol. Untreated, this [canine] hypoglycemia can be life-threatening.
- jerf 12y ago
  That doesn't help much, though. There's all kinds of things that are toxic to one species and not another, even just in Mammalia, and everything that anything anywhere ever eats is definitely not good for some other species.
  - 001sky 12y ago
    The mechanism of toxicity (in dogs) is specifically relevant. There are multiple studies showing that artificial sweeteners in general are unhealty -- the body recognizes them -- and takes a variety of actions as a result. Clearly these reactions in some cases may be simply performance related (see: http://www.gssiweb.org/Article/sse-118-carbohydrate-mouth-rinse-performance-effects-and-mechanisms http://www.gssiweb.org/Article/sse-118-carbohydrate-mouth-ri...). Whilst others can be catastrophic (see: xylitol in dogs).
erickhill 12y ago
Agreed, or stevia (which is found in some high-priced colas, among other products). http://en.wikipedia.org/wiki/Stevia http://en.wikipedia.org/wiki/Stevia
whyenot 12y ago
Xylitol was not included in the study. Because xylitol is absorbed more slowly from the gut and gut microflora appear to be the mechanism of action found in this study, I'd personally be at least a little concerned. Mice in this study were given sweeteners for 11 weeks, long enough that their use apparently led to changes in microflora which were associated with glucose intolerance. Existing studies of xylitol could well be for much shorter lengths of time and might not have been able to detect these kinds of changes.
- yupmetoo 12y ago
  I wonder then if its the absorption of the gut or if it is the conditioning. If the gut flora have to adapt to trying to break down an impenetrable compound they might become super strong at breaking down simpler molecules no?

coldcode 12y ago

People rarely consider how what you eat affects your microflora which then affects various other systems and may even affect your desire to consume.

at-fates-hands 12y ago
This is the same thing with having good oral hygiene. So many serious health problems can be traced back to poor oral hygiene. If you go nothing else, make sure you take good care of your mouth, gums and teeth!
- deleted 12y ago
  [deleted]
viewer5 12y ago
Without delving into a bunch of scientific papers, how could I go about considering how my dietary choices influence my microflora for better or worse?
- tormeh 12y ago
  Well, you can't really do that. We don't know nearly enough about it. Hell, we're not even good at normal dietary science yet and the whole gut bacteria science field is really new. You can find a healthy and fit person and get them to give you some of their gut flora and then eat it. That could probably work. It also might make you sick (I imagine) and it's terribly disgusting: "On a scale from swallowed to poo, how do you want my eaten food?"
  - dasil003 12y ago
    I don't think that would work (bacteria living the colon can not necessarily survive all the way through the digestive tract). What is an accepted form of gut biome therapy is a stool transplant: http://en.wikipedia.org/wiki/Fecal_bacteriotherapy http://en.wikipedia.org/wiki/Fecal_bacteriotherapy

Dirlewanger 12y ago

"metabolic abnormalities" Anyone know if they go into these into the paper? Really want to know what else is in the paper; I chew way too much sugar-free gum.

e40 12y ago
I chew way too much sugar-free gum. At first I thought, yeah, this will never be a problem for me, then I realized the only thing I do consume with artificial sweeteners is gum. I do hope the doses are low enough not to be a problem, but I want to know!
driverdan 12y ago
Based on the doses they used you'd have to chew multiple packs of gum per day to get the same amount of sweetener.
spmurrayzzz 12y ago
Most sugar-free gum uses some type of sugar alcohol (e.g. xylitol, erythritol). These are not technically-speaking considering NAS. Their mechanisms of absorption vary wildly and, while in some cases they can cause digestive stress in large amounts, there is no good evidence AFAIK that they have a deleterious effect on gut microbiota.

SCHiM 12y ago

Can anybody explain or guess what the consequences of this intolerance are or could be?

pyre 12y ago
It's a pre-diabetic state: http://www.diabetes.co.uk/glucose-intolerance.html http://www.diabetes.co.uk/glucose-intolerance.html
ddebernardy 12y ago
You might find this video on fructose and metabolic disease (of which glucose intolerance is a symptom) interesting: http://www.youtube.com/watch?v=dBnniua6-oM http://www.youtube.com/watch?v=dBnniua6-oM
- pyre 12y ago
  It's worth noting that there are many critics of this guy.
  - ddebernardy 12y ago
    True. As I understood them though, the criticism was primarily about his message that fructose would be the key or only reason of metabolic syndrome, or his depiction of sugar as pure evil rather than as something which you can consume in small amounts, more than about the effects of fructose itself. (When not, connections between the critic and the sugar or food industry were quick to Google, thereby reducing the credibility to zero.) This may have changed since I spent time digging into it, though, so please expand if it has.
    - pyre 12y ago
      My point was just to point out that criticism exists. Loads of people watch that video and don't do other research on the topic.

nostromo 12y ago

Here's a nice write up about the results: http://www.newscientist.com/article/mg22329872.600-artificial-sweeteners-linked-to-glucose-intolerance.html http://www.newscientist.com/article/mg22329872.600-artificia... Note that the mice were given the human equivalent of 18 to 19 cans of diet soda a day.

dang 12y ago
Thanks. We changed the url to that from http://www.nature.com/nature/journal/vaop/ncurrent/full/nature13793.html http://www.nature.com/nature/journal/vaop/ncurrent/full/natu... because the paper is paywalled. There is also http://www.economist.com/news/science-and-technology/21613311-sugar-substitutes-may-mess-gut-bacteriacausing-obesity http://www.economist.com/news/science-and-technology/2161331..., via https://news.ycombinator.com/item?id=8331143 https://news.ycombinator.com/item?id=8331143.
kazinator 12y ago
This write up also only implicates saccharin in the harmful alterations of the gut flora, not other sweeteners. Yet the introductory text talks about artificial sweeteners are a group. You cannot confirm the effects of "artificial sweeteners" as a category with an experiment that is based on saccharin. They are all different molecules. A bacterium that thrives on saccharin might not consume sucralose or aspartame. Also glaringly absent is any mention of the sugar alcohols: sorbitol, xylitol, maltitol. Who cares about saccharin. It is an outdated sweetener which is not widely used. Where can you find a diet soft drink or protein bar sweetened with saccharin?
- randallsquared 12y ago
  First, I care, since saccharin is (was?) my preferred sweetener, for coffee, etc. Second, saccharin is very widely available at restaurants and so forth, coming in a very close second to aspartame, in my experience.
  - kazinator 12y ago
    I know that it's available if you want it; but then, so are alcohol and cigarettes. If a study could link popular, widely-deployed sweeteners found in processed foods and drinks, that would point to a big public health issue. A problem with saccharin doesn't point to a wide-spread public health issue. Sacharrin has been vilified on and off over its entire lifetime. My parents' and grandparents' generation believed that it was a harmful poison, for instance; I remember hearing that as a kid. Only in the year 2000, in the US, were requirements for warning labels lifted, which had been in the effect since the 1970's, when saccharin was linked to cancer in rodents: http://en.wikipedia.org/wiki/Saccharin#Warning_label_addition_and_removal http://en.wikipedia.org/wiki/Saccharin#Warning_label_additio... In spite of the lift, it doesn't seem that saccharin has made a comeback. Part of the reason could be taste. Particular mixtures of sweeteners are used in diet foods sweeteners in order to better simulate the taste of sugar.

sadfaceunread 12y ago

This is an impressive piece of work but I worry that a larger amount of work is needed in the relationship between glucose intolerance, diabetes and metabolic syndromes in general. The fact that glucose intolerance is induced by a high sugar diet and leads towards a path of clinical outcomes ending in diabetes, doesn't necessarily indicate that glucose intolerance developed via artificial sweetener consumption is indicative of being on the same clinical pathways towards metabolic syndrome and diabetes.

sp332 12y ago

Does this mean diabetes could (in some cases) be caused by gut bacteria? Can we reduce diabetes risk factors with targeted antibiotics that attack certain glucose-intolerance-causing bacteria?

jonnathanson 12y ago
It's fiendishly difficult to pry apart correlation and causation for complex conditions like diabetes (which we're steadily reconceptualizing as less of a "disease," and more of a chain reaction of metabolic and hormonal disorders). Changes in gut bacteria are associated with the condition sometimes called "pre-diabetes," or a "pre-diabetic state." But we're not yet sure if they are a causative factor, if they are the result of the condition, or if they're simply co-morbid with it. Whatever the case, gut bacteria appear to play a vital role in our metabolic health, and we're only beginning to explore this area in earnest.
cauterized 12y ago
There's also some indication from other studies that antibiotics killing off symbiotic gut flora may be implicated in diabetes.
UrMomReadsHN 12y ago
Yes, absolutely possible. There is so much potential in gut bacteria research and we are only starting to recently scratch the surface with it. I get really excited about the topic of gut bacteria for some reason, it is just very interesting. Its hard to separate cause and effect right now though. There also may be a snowball effect. We just know so little so there is a lot of research that needs to be done. Antibiotics are unlikely. Fecal transparents are much more likely. Fecal transparents are starting to be used for c. Diff infections with success.

Someone1234 12y ago

So the public funds studies, which they give to journals for free, who then sell access for $3.99/view. I'm really not sure this was the "free exchange of ideas" which science is based upon. Even the New York times only charges $3.75/week (the nature price is per article/view NOT per week, it would be $4.14 if their $199 plan was weekly) and the NYT has to actually pay journalists to create the content. Nature gets all their content for free. So what are Nature's expenses anyway? They no longer have to type set as it is just an identical PDF which is sent to them. Is hosting and management of the web-site really so costly that it is $3.99/article?

Swizec 12y ago
> So what are Nature's expenses anyway? The prestige. (theoretically that means organising the peer review part of science and such)
- AUmrysh 12y ago
  Nature has the highest impact factor of any research journal. They can basically ask for whatever they want at this point, because someone out there will be willing to pay it to get their paper in nature.
yincrash 12y ago
The peer review process, I would think.
- Someone1234 12y ago
  They don't pay for people to peer review as far as I know.
  - dragonwriter 12y ago
    That the individual peer reviewers aren't paid does not imply that coordinating the peer review process is cost-free to the publication.
- 12y ago

WesleyRourke 12y ago

Raised insulin levels are much more complicated than we once thought. You can get an insulin response from artificial sweeteners just swished in your mouth and spat out. Solution, eat real food when you can

3rd3 12y ago
Do you have a source for that? The last time I checked this worked with mice, but humans showed no insulin response from sweet taste alone.
- BSousa 12y ago
  I don't right now, but from my times when competing, I used to read a lot of science based research on nutrition and there was a study that said swishing a carb rich liquid was enough to trigger it. I think I first saw it referenced on an old edition of 'The Complete Guide to Sports Nutrition' by Anita Bean
  - demallien 12y ago
    Artificial sweeteners are not "carb rich". That's kind of the point of them...
    - BSousa 12y ago
      What I meant was there is a possibility of it happening as a sweet taste (parent didn't mention sweeteners, just sweet taste) response since there is a similar response to carb rich drinks (study didn't mention the kind of carbs so no idea)
  - spmurrayzzz 12y ago
    Are you referring to the salivary amylase mechanism? Sounds similar but actually requires starch to be activated. I'm aware of no RCT or even epidemiological research to suggest that NAS causally mediates insulin response.
- 12y ago

jimrandomh 12y ago

The headline is suspicious, but unfortunately, this article is paywalled, so I can't tell what's really going on. The main problem with the headline is that it lumps together "artificial sweeteners" as a category, when that is in fact a pretty widely varied class of molecules.

glaugh 12y ago
Agreed. From the article Nostromo just posted[1], looks like the mouse models were based on aspartame, saccharin, and sucralose, and the human subjects were taking saccharin. [1] http://www.newscientist.com/article/mg22329872.600-artificial-sweeteners-linked-to-glucose-intolerance.html#.VBnjFWRdX4K http://www.newscientist.com/article/mg22329872.600-artificia...

FranOntanaya 12y ago

Do they compare pure sweetener diet with pure sugar diet calorie per calorie, and sweetness units per sweetness units? Sweeteners are still caloric, the point is that they provide the same sweetness for less calories.

mcmancini 12y ago

Overall, this was a nicely done study. The microbiome is fascinating and an exciting area of research. One criticism however would be that the dose of artificial sweetener tested was atypically high. It'll be neat to see further research into the cause of variable responses of the subjects to the artificial sweeteners.

cschmidt 12y ago
According to the New Scientist article others have linked to, the equivalent human dose was 9-12 packets of sweetener a day. I'm sure there are heavy coffee drinkers that go through that much. I also don't like those studies where the human equivalent dose is like 50 pounds of sweetener a day, or something silly. This one isn't so bad.
- whyenot 12y ago
  For comparison, that amount of sweetener (9-12 packets) is found in about 3 cans of Diet Coke (35mg aspartame per packet, 125mg per Diet Coke). I suspect there are quite a few people who consume more than that in a day.
- mcmancini 12y ago
  I guess I'm having trouble figuring out where the numbers are coming from. I'm seeing that the FDA recommended maximum dose for aspartame is 50mg/kg/day. Assuming a 70kg Standard Man, that's 3.5g/day of aspartame. Diet Coke has 125mg per 12oz. can, so that would be 28 cans/day. Each packet should be around 35mg aspartame, so 100 packets/day (the amount of aspartame per packet was hard to find, and the approx. was from an American Cancer Society article). Agreed that 9–12 packets doesn't sound like much, but I think we're talking way more than that.
  - deleted 12y ago
    [deleted]

kazinator 12y ago

This seems misleading. If you go through the graphs and results, what emerges is that only the sweetener saccharin has that altering effect on the gut bacteria. I cannot find among the results any claim that the other NAS that were studied (sucralose and aspartame) have the effect. The thing is that saccharin is not widely used any more. If saccharin is found to be harmful, that is nice to know, but not highly relevant.

tokenadult 12y ago

I'm paywalled out of seeing the whole article until I try a workaround (after which I may expand this comment), but I think we can all see the abstract of the article if we follow the link kindly submitted here. Yet some questions in other comments raise issues that are already responded to by the article abstract. Here is the full text of the article abstract available in the free view at the link: "Non-caloric artificial sweeteners (NAS) are among the most widely used food additives worldwide, regularly consumed by lean and obese individuals alike. NAS consumption is considered safe and beneficial owing to their low caloric content, yet supporting scientific data remain sparse and controversial. Here we demonstrate that consumption of commonly used NAS formulations drives the development of glucose intolerance through induction of compositional and functional alterations to the intestinal microbiota. These NAS-mediated deleterious metabolic effects are abrogated by antibiotic treatment, and are fully transferrable to germ-free mice upon faecal transplantation of microbiota configurations from NAS-consuming mice, or of microbiota anaerobically incubated in the presence of NAS. We identify NAS-altered microbial metabolic pathways that are linked to host susceptibility to metabolic disease, and demonstrate similar NAS-induced dysbiosis and glucose intolerance in healthy human subjects. Collectively, our results link NAS consumption, dysbiosis and metabolic abnormalities, thereby calling for a reassessment of massive NAS usage." AFTER EDIT: After reading all the comments in this thread to the time of this edit, I see that some participants here disagree entirely with how I commented at first (as above). I note their opinion with interest and say here for the record simply that I saw previous comments that raised questions about information that is available in the article abstract for all of us to read. I meanwhile did find my workaround to get the full text of the article (I have library access with journal subscriptions for one aspect of my work, which is rather slow and buggy) and from the full article text I see that the experimental approach the researchers tried--feeding mice with the artificial sweetener to see if that changed gut microbiota in the mice, and then transferring the gut microbiota to other mice--did indeed bring about clinical signs consistent with the idea that the sweetener itself might cause related clinical signs in human beings. "To test whether the microbiota role is causal, we performed faecal transplantation experiments, by transferring the microbiota configuration from mice on normal-chow diet drinking commercial saccharin or glucose (control) into normal-chow-consuming germ-free mice (Extended Data Fig. 1e). Notably, recipients of microbiota from mice consuming commercial saccharin exhibited impaired glucose tolerance as compared to control (glucose) microbiota recipients, determined 6 days following transfer (P < 0.03, Fig. 1e and Extended Data Fig. 2e). Transferring the microbiota composition of HFD-consuming mice drinking water or pure saccharin replicated the glucose intolerance phenotype (P < 0.004, Fig. 1f and Extended Data Fig. 2f). Together, these results establish that the metabolic derangements induced by NAS consumption are mediated by the intestinal microbiota." This preliminary finding, which of course needs to be replicated, has caused alarm in the industry, according to the link participant nostromo kindly shared in this thread.[1] There is epidemiological signal that human beings who consume a lot of artificial sweeteners are not especially healthy people compared to people who consume few. Teasing out the mechanism that may underly that observational finding will take more research, but this is important research to get right. "To study the functional consequences of NAS consumption, we performed shotgun metagenomic sequencing of faecal samples from before and after 11 weeks of commercial saccharin consumption, compared to control mice consuming either glucose or water. To compare relative species abundance, we mapped sequencing reads to the human microbiome project reference genome database16. In agreement with the 16S rRNA analysis, saccharin treatment induced the largest changes in microbial relative species abundance (Fig. 2a, Supplementary Table 2; F-test P value < 10−10). These changes are unlikely to be an artefact of horizontal gene transfer or poorly covered genomes, because changes in relative abundance were observed across much of the length of the bacterial genomes, as exemplified by one overrepresented (Bacteroides vulgatus, Extended Data Fig. 7a) and one underrepresented species (Akkermansia muciniphila, Extended Data Fig. 7b)." The authors sum up their experimental findings by writing "In summary, our results suggest that NAS consumption in both mice and humans enhances the risk of glucose intolerance and that these adverse metabolic effects are mediated by modulation of the composition and function of the microbiota. Notably, several of the bacterial taxa that changed following NAS consumption were previously associated with type 2 diabetes in humans13, 20, including over-representation of Bacteroides and under-representation of Clostridiales. Both Gram-positive and Gram-negative taxa contributed to the NAS-induced phenotype (Fig. 1a, b) and were enriched for glycan degradation pathways (Extended Data Fig. 6), previously linked to enhanced energy harvest (Fig. 2c, d)11, 24. This suggests that elaborate inter-species microbial cooperation may functionally orchestrate the gut ecosystem and contribute to vital community activities in diverging environmental conditions (for example, normal-chow versus high-fat dietary conditions). In addition, we show that metagenomes of saccharin-consuming mice are enriched with multiple additional pathways previously shown to associate with diabetes mellitus23 or obesity11 in mice and humans, including sphingolipid metabolism and lipopolysaccharide biosynthesis25." There have been a lot of questions raised in this thread, and indeed the article itself raises plenty of interesting questions to follow up with further research. When discussing a new preliminary research finding like this, we can work outward from the article abstract to news reports about the article findings to the article text itself to focus on the known issues and define clearly the unknown issues. I appreciate comments from anyone here about how I can help contribute to more informed and thoughtful, in Hacker News sense of "thoughtful,"[2] discussion of research on human nutrition. Other comments here asked why we should respect journal paywalls at all, and the basic answer to that question is a basic principle of economics, that people respond to incentives. (That's the same reason you don't found a startup that you expect will always lose money for all time.) Nature is one of the most-cited scientific journals in the world, so it's a big coup to be published there, and that means Nature gets a lot of submissions. To slog through all the submissions with adequate editorial work does cost money. (I used to be a junior editor of an academic journal.) The article gets more attention (it has received a lot of attention in this thread) if it is in a better rather than worse journal. Some journals are lousy enough to publish anything, and those journals beg for submissions, but Nature can charge for subscriptions and impose paywalls (which expire for government-funded research, with author sharing of author manuscripts on free sites usually being mandatory after a year embargo) because what it publishes is often worth reading (as here). AFTER ONE MORE EDIT: I see that while I was reading the fine article from Nature submitted to open a thread, my comment is now part of a thread that is about the New Scientist popular article on the same research finding. This will be confusing to readers newly visiting this thread. The title of the Nature article is "Artificial sweeteners induce glucose intolerance by altering the gut microbiota" (the Hacker News thread title I saw, per the usual rule of using the article headline as the submission headline) and the article DOI is 10.1038/nature13793 for the full article published online (behind a paywall) on 17 September 2014. [1] http://www.newscientist.com/article/mg22329872.600-artificial-sweeteners-linked-to-glucose-intolerance.html http://www.newscientist.com/article/mg22329872.600-artificia... [2] "The most important principle on HN, though, is to make thoughtful comments. Thoughtful in both senses: both civil and substantial." https://news.ycombinator.com/newswelcome.html https://news.ycombinator.com/newswelcome.html

mladenkovacevic 12y ago

I hope this doesn't hold true for stevia as well :/

medell 12y ago
Pure stevia is not artificial, but the verdict is still out on safety. It seems to be OK... for now. I use it, though I try to use honey as well.
- UrMomReadsHN 12y ago
  The stevia whole leaf has been used for centuries in teas on Brazil. It has been used as an artificial sweetener in Japan for decades accounting for around 40% of the sweetener market there. Weirdly, I always bought it labeled as a dietary supplement in the US before the FDA approved some extracts as food additives.
- UrMomReadsHN 12y ago
  The stevia whole leaf has been used for centuries in teas on Brazil. It has been used as an artificial sweetener in Japan for decades accounting for around 40% of the sweetener market there. Weirdly, I always bought it labeled as a dietary supplement in the US before the FDA approved some extracts as food additives.
cmapes 12y ago
That was my first thought too, I use stevia in almost everything.

driverdan 12y ago

Can someone post the full paper? The charts shown at the bottom seem to contradict some of their conclusions and implications. For example, some of the sweeteners seemed to result in lower chow consumption and increased energy expenditure. That would be a positive effect that isn't mentioned in the abstract.

oomkiller 12y ago

This seems very misleading. The abstract (available without paywall) mentions a group of sweeteners, whereas the findings seem to show that only saccharin has these negative effects. I feel like NAS are probably bad, but without evidence to support it they should not claim that in the abstract.

lee 12y ago

So given a choice, between Diet Soda vs. Normal Soda, what would be worse for your overall health? I imagine even with increased glucose intolerance, you're still better off choosing Diet?

Wingman4l7 12y ago
Depends on how much you're consuming.
_greim_ 12y ago
Not a direct answer, but noting that there's also a third choice, which is to not drink anything sweet. I'll chug a diet soda once in a while because what's the downside? But in light of new compelling evidence I might change that habit without too much fuss.
dragonwriter 12y ago
You're probably better off not choosing carbonated liquid candy -- especially not doing so regularly and in significant quantities -- even if the sweetener happens to be non-caloric. And the point where you've reduced your choices to regular soda vs. diet soda, you've already failed.
- tedunangst 12y ago
  Failed at what?
  - marcosdumay 12y ago
    Failed at having a healthy diet. (That is, if he does make that choice frequently - a one time event probably won't change anything.)
    - parasubvert 12y ago
      In what way is it unhealthy? Aspartame has zero calories, and decades of studies showing its safety. Put another way, if you want to avoid sugar (which is much less healthy than aspartame), besides water, there's tea, coffee, flavoring mixes like Crystal Light, and various prepared sugar free soft drinks. Many prefer variety over water. There's little scientific basis to believe drinking any of these things are bad. Drinking a mix of these is quite a bit healthier for an adult than chugging juice or sugared drinks - unless you're explicilty trying to carb-load. Milk is a healthy alternative but debatable due to its effects on some.

kolev 12y ago

Sweeteners are suspected to have downed the Roman empire (via lead poisoning), so, learn from history and just change your taste norm and you'll live longer and happier. I had a sweet tooth once and it took about a couple of years to even not being able to tolerate it. The weak find excuses, the strong adapt and improve. Just reject anything with refined sugar or fancy new "healthier" sweeteners - do you like sugar more than tomorrow? Cane sugar is not healthier than HCFS (it might be just slightly less harmful). Agave "Nectar" actually has significantly more fructose than HCFS... and it's not unprocessed as claimed, and so on. Stevia is slightly different, the plant has other benefits, but I wouldn't ever use the adulterated version (Reb A or whatever). Hack your taste buds, hackers!

kolev 12y ago
Sugar alcohols (xylitol, sorbitol, maltitol, mannitol, erythritol) have the same negative effect on the gut microbiota.

mratzloff 12y ago

FDA acceptable daily intake (ADI) for aspartame is 50 mg per kg of body mass.[0] For an individual 180 pounds, that's about 82 kg. That means his ADI is 4100 mg. Aspartame in popular diet sodas is between 50 and 125 mg.[1] You'd have to drink A LOT of diet soda to reach these levels. [0] http://www.cancer.org/cancer/cancercauses/othercarcinogens/athome/aspartame http://www.cancer.org/cancer/cancercauses/othercarcinogens/a... [1] http://static.diabetesselfmanagement.com/pdfs/DSM0310_012.pdf http://static.diabetesselfmanagement.com/pdfs/DSM0310_012.pd...

lucaspiller 12y ago
I have a friend who used to drink nothing but Diet Coke. He went through a few 2l bottles a day. According to that link (assuming it's the same in Europe), Diet Coke is 125mg per 8 ounces, so a 2l bottle is 125 / 8 x 70.4 = 1100mg. So if he drank four 2l bottles, that's over the daily limit.

skue 12y ago

For those not aware, other studies have shown that consuming diet soda may actually increase the chance of obesity. So that is not necessarily news. If you are curious, here is a pretty good study (full text): http://onlinelibrary.wiley.com/doi/10.1038/oby.2008.284/full http://onlinelibrary.wiley.com/doi/10.1038/oby.2008.284/full More recently, studies have tried to determine whether there is a satiety or protein mechanism that can explain this, whereas this new study demonstrates that gut flora may play a role. This needs to be confirmed, and there may still be other mechanisms at play as well, but it is interesting. (Disclaimer: I do have a healthcare background, but am not a researcher in this field. Would be happy to hear more from anyone who is.)

Istof 12y ago
I keep drinking diet soda and I still can't gain weight (news: big eaters get fat)
jonnathanson 12y ago
Indeed. I think it helps to unpack the various claims being studied: 1) Carcinogenicity. Do certain sweeteners cause harmful mutations and increase cancer risk? This is one of the oldest and most frequent allegations, especially against saccharin and aspartame. Mostly inconclusive, though both sweeteners have been exonerated at least as often as they've been accused. 2) Insulin triggering. Artificial sweeteners may not bear the caloric load of sugars and starches -- but do they trigger the release of insulin, just the same? Again, the jury is still out, but certain sweeteners (aspartame, sucralose, and possibly saccharin) are looking suspect. 3) Caloric load. Some sweeteners and putatively indigestible molecules (sugar alcohols, "resistant starches," etc.) may contain more effective calories than in vitro studies predict them to contain. This is because the chemicals aren't digested in the traditional sense, but are fermented and absorbed in the gut. Caloric bioavailability is often different from nominal calorie count. (Indeed, this is the entire principle behind the supposed benefits of resistant sweeteners and starches; those benefits may have been overstated or misunderstood). 4) Disruption or adverse selection of gut microbiota. As detailed in this study. While not all sweeteners have been implicated here, this field of study is only just kicking into high gear. It seems reasonable to suspect that molecules fermented by / consumed by gut bacteria could have some effect on flora composition. Many sweeteners fit that criterion. 5) Other toxicities. Liver or kidney toxicity, neurotoxicity, endocrine disruption, etc. As with carcinogenicity, the jury is still out. Unlikely for some sweeteners that are not metabolized via these pathways. Possible for others. Most sweeteners (all?) on the market right now are generally recognized as safe in this respect, despite popular beliefs to the contrary. Notable exceptions exist for those with rare metabolic or genetic disorders, such as phenylketonuria (aspartame contains phenylalanine). 6) Side effects. Some sweeteners, particularly those in the sugar alcohol family (and sorbitol especially), can cause laxative effects and other GI-related issues. Individual tolerance can vary. Breaking this category out from #4 because the action here can be purely mechanical (i.e., increasing intestinal water absorption). I'm not a doctor or medical researcher myself. Just an interested nerd. But I have been following this area for awhile. I welcome any corrections, comments, or additions from people more knowledgeable than I am. I assume there are many such people on HN. :)

blackbagboys 12y ago

The New Scientist article notes that four of the seven human subjects who consumed three to four sachets of sweetener a day saw a significant change in their gut bacteria. As someone who has consumed significantly more than that for a very long time, my question would be, did their gut flora reconstitute itself after they stopped using the sweetener? And if not, how could you go about repopulating your microbiome short of a stool sample?

BadCookie 12y ago
A probiotic might help. A gastroenterologist once recommended Align to me, if that's helpful to you.
uladzislau 12y ago
The gut flora is as resilient as any other part of human body. It might take a significant time though. I've heard Korean food helps a lot because it's fermented. Also usual bifido youghurts you'll find at any grocery store.
acomjean 12y ago
The does in the article is higher than your post: 3-4 sachets taken 3 times a day. Those packets to me are sweet. I alternate between honey and half a packet in my tea. Gut Flora do come back (eg after taking antibiotics which cuts them down). They're crowded in there, so the ratio of them is important. Everyone has different ratio and there is no easy way to measure and control that.

kens 12y ago

This result seems pretty strange to me - why would artificial sweeteners affect bacteria's metabolism in this way? It seems like a bizarre coincidence that bacteria would react in the same way to three different sweeteners, unless they have receptors that happen to match human taste receptors (which also seems unlikely). In other words, to bacteria these sweeteners should just seem like unrelated random chemicals. (I read the Nature paper - most of it looks at saccharin since that had the strongest response, but all three artificial sweeteners caused marked glucose intolerance.)

joekrill 12y ago
Well, not everything makes immediate intuitive sense.
- dragonwriter 12y ago
  Yeah, that's pretty much the whole reason we need science.
lnanek2 12y ago
Bacteria are, in general, much more capable at processing various chemicals than humans are. They can even pass around packets of genetics, called plasmids, across species. So it isn't really surprising if bacteria can flourish eating something that tastes sweet to people, but doesn't provide any calories to people. There have been some artificial sweeteners shown to hurt bacteria more than people - Xylitol is famously used in gum, for example, because it costs bacteria energy to try to eat it, but they gain nothing, thus helping to fight bacteria growth.
- calinet6 12y ago
  Aspartame is essentially just a collection of amino acids, so it's even more feasible (in a total guessing hand-wavey way) that gut bacteria would be affected.

duschang27 12y ago

Abstract can be found here. http://www.nature.com/nature/journal/vaop/ncurrent/full/nature13793.html http://www.nature.com/nature/journal/vaop/ncurrent/full/natu...

biot 12y ago

I like how all the people who benefit from artificial sweeteners are refuting something which the study doesn't claim. For example: "The International Sweeteners Association (ISA) says it strongly refutes the claims made in the study: 'There is a broad body of scientific evidence which clearly demonstrates that low-calorie sweeteners are not associated with an increased risk of obesity and diabetes as they do not have an effect on appetite, blood glucose levels or weight gain.'" It's true that artificial sweeteners have no immediate effect on appetite, blood glucose levels, nor weight gain. None of these are claims made by the study. Everyone is refuting the immediate effects of artificial sweeteners. The study claims that after consuming artificial sweeteners, if you then consume something naturally sweet, the prior consumption of an artificial sweetener alters your glucose tolerance levels. It's the equivalent of saying that removing all the trees from around rivers has no effect on fish population because clearly fish don't live in trees. But it's the secondary effects of this which such a statement ignores: the increase in soil erosion impacting water quality, change in water temperature due to having more direct sunlight, and so on. Also: "'Decades of clinical research shows that low-calorie sweeteners have been found to aid weight-control when part of an overall healthy diet, and assist with diabetes management,' says Gavin Partington of the British Soft Drinks Association." This has little meaning without having a reference point to compare the results to. If the study is correct, take one group of people who use diet soft drinks with an overall healthy diet and compare it to another group of people who consume the same overall healthy diet but drink water instead of diet soft drinks, and the group that drinks water should have a better glucose tolerance response than the diet soft drink group.

deleted 12y ago
[deleted]
azakai 12y ago
> It's true that artificial sweeteners have no immediate effect on appetite Yes, but the quote you give doesn't mention immediate effects in particular. And to the contrary, they mention things like obesity and diabetes which are not immediate effects. To me, it sounds like they are not saying what you say they are.

pistle 12y ago

The industry takeaway should be to try to isolate the bacteria that play the secondary part in the glucose resistance, then put ANOTHER additive in the drinks to kill that bacteria, then sell a more expensive NEW zero calorie drink? People like sweet. Let's make sweet safe.

louwrentius 12y ago

The maximum dose is quite high, but does the effect also occurs when consuming more sane dosage a day?

devindotcom 12y ago

Doesn't seem so strange - if you create a sugar deficit in your body by significantly reducing your intake, wouldn't you expect the body to be more responsive to sugars when it encounters them?

mark-r 12y ago
I believe that's why they had a control group with unsweetened water.

dbbolton 12y ago

Now let's see a human study where people who consume those sweeteners, eat carbohydrates in moderation, and exercise regularly are still at increased risk for diabetes.

voidlogic 12y ago

I'm not really surprised Saccharin isn't great for you personally- but this isn't so damning there are many other artificial sweeteners to choose from. https://en.wikipedia.org/wiki/Sugar_substitute#Artificial_sugar_substitutes https://en.wikipedia.org/wiki/Sugar_substitute#Artificial_su... I'd of course like to see them all studied in this manner.

rcthompson 12y ago

For some biological context, we have taste receptors in our digestive tracts identical or nearly identical to those on our tongue, only the ones in our digestive tract are not hooked directly to sensory neurons, but instead trigger endocrine signals and such. Since the receptors are identical, then anything that tastes sweet on your tongue will activate these receptors as well. If I recall my metabolism course correctly, studies have found that artificial sweeteners can trigger insulin release through these receptors in the same way as real sugar (leading to possible hypoglycemia as your body compensates for a rush of sugar that never comes). So basically, I have no trouble believing that artificial sweeteners can have many of the same long-term health effects as excessive consumption of real sugar, since they're already known to have many of the same short-term effects, including effects on insulin regulation.