Marks Daily Apple
Serving up health and fitness insights (daily, of course) with a side of irreverence.
3 Feb

Do Artificial Sweeteners Cause an Insulin Spike?

The notion that artificial sweeteners (and sweet tastes in general) might produce an insulin response is one of those murky memes that winds itself around the blogs, but it’s never stated one way or the other with any sort of confidence. I briefly mentioned the possibility of non-caloric sweeteners influencing satiety hormones in last week’s diet soda post, and a number of you guys mentioned the same thing. Still, I’ve never seen unequivocal evidence that this is the case.

This whole idea first came to my attention some time ago when my dog Buddha got into a bottle of “alternative sleep assists” which contained, among other things, 5 HTP (version of l-tryptophan) and xylitol (sugar alcohol). Long story short, dogs can’t take xylitol because it causes a spike in insulin, which then severely depletes blood glucose. Buddha got past this with a trip to the vet’s at 10:30 Sunday night (thanks, Dr. Dean). But it occurred to me that the same effect might be seen in humans, which is why I pose the question today…

Do artificial sweeteners induce insulin secretion (perhaps via cephalic phase insulin release, which is sort of the body’s preemptive strike against foods that will require insulin to deal with)?

One of the reasons a definitive answer is rarely given is that the question is improperly framed. Artificial sweeteners is not a monolithic entity. There are multiple types of sweeteners, all of them chemically distinct from each other. A more useful question would be “What effect does [specific artificial sweetener goes here] have on insulin?” So let’s go around the circle and ask.

Does aspartame (aka Equal and Nutrasweet) affect insulin?

Aspartame is pretty gross stuff, what with its awful taste and hordes of people who get terrible reactions from consuming it, but that’s not what we’re interested in today. Luckily, there is a good amount of research explaining what, if any, effect aspartame has on insulin secretion.

One study found that protein produced a significant insulin response, while aspartame had no effect on insulin levels.

Another also found that aspartame had no effect on the insulin response in humans, whether alone or combined with carbohydrates.

Another earlier study (full PDF) examined the effects of aspartame on prolactin, cortisol, growth hormone, insulin, and blood glucose levels and found it had none. The authors used the same amount of aspartame you’d find in a standard artificially-sweetened drink but were unable to record any significant hormonal alterations.

A study of forty-eight healthy volunteers found no evidence that aspartame has an effect on insulin levels.

Overall, the evidence seems to suggest little, if any, effect on insulin secretion as a result of tasting or consuming aspartame.

Does saccharin (aka Sweet’N Low) affect insulin?

Although saccharin has lingered in obscurity and consumer banishment (who ever really picks Sweet ‘n’ Low, anyway?) for most of the last couple decades (until recently when the EPA dubbed it safe for human consumption), there is some research on its effects on insulin.

In one study, fasted human subjects swished around eight different taste solutions for 45 seconds, and then spat them out. No swallowing. Only the sucrose and saccharin solutions activated a cephalic phase insulin release.

On the other hand, another study using humans found the opposite: swishing and spitting sweet solutions (even caloric ones using sucrose) did not elicit CPIR, while another study found that neither saccharin nor aspartame influenced insulin secretion in both fasted diabetics and non-diabetics (although aspartame-fed subjects had slightly higher insulin levels than the control and saccharin groups, this was physiologically irrelevant given the steady blood glucose levels).

The evidence for saccharin’s effect on insulin is mixed, but either way, it doesn’t appear to have too big of an impact in real world terms.

Does acesulfame K (aka Sunett and Sweet One) affect insulin?

In one study, researchers found that direct transfusions of acesulfame K increased insulin secretion in rats in a dose-dependent fashion. The same researchers performed an in vitro study, subjecting isolated rat pancreatic islets to acesulfame K solutions, and found that the artificial sweetener was an independent actor on insulin secretion. Both indicate that there is some effect, but it’s difficult to draw any conclusions from in vitro rat studies using isolated pancreatic cells or in vivo rat studies using direct transfusions of sweeteners (as opposed to oral dosing).

Another study using isolated pancreatic cells found that only those artificial sweeteners with a bitter aftertaste (acesulfame K, saccharin, stevia, and cyclamate) augmented the insulin response in the presence of glucose. Aspartame, which does not have a bitter aftertaste, did not affect insulin. Note, though, that this was an in vitro study using isolated cells and that the presence of glucose was a prerequisite for insulin secretion. Of course, dieters slurping down artificial sweeteners do it during meals, most of which tend to feature large amounts of glucose.

Acesulfame K appears to affect insulin levels, although this effect has only been shown in contrived settings – either in the presence of glucose in isolated cells (in vitro), in isolated cells in without glucose (in vitro), or by direct transfusions without the presence of glucose (in vivo). We haven’t seen people orally taking acesulfame K in a fasted state and having an insulin response. Yet.

Does sucralose (aka Splenda) affect insulin?

Sucralose activates the sweet receptors in taste buds, and some in vitro studies have shown that sucralose can stimulate the release of incretin hormones, which increase the secretion of insulin, via the sweet taste receptors in enteroendocrine cells (located in the gut). An in vivo study of sucralose infusions into the gut, however, showed that it does not stimulate the incretin hormones GLP-1 or GIP, does not release insulin, and does not slow gastric emptying.

Another in vivo study, this time using healthy human subjects, got similar results: oral dosing of sucralose did not induce a cephalic insulin response, nor did it affect GLP-1. Not even appetite was affected.

The commercial version of sucralose, Splenda, is cut with dextrose as a bulking agent. Dextrose is essentially glucose, which certainly elicits an insulin response, so there’s definitely the potential for a slight insulin response to Splenda, but there’s not much if any evidence that sucralose has an independent in vivo effect on insulin.

Recently, a review of in vivo studies concluded that “low-energy sweeteners” do not have any of the effects on insulin, appetite, or blood glucose predicted by “in vitro, in situ, or knockout studies in animals.” As far as the clinical studies go, I think I’d have to agree. Am I going to use the stuff? No; there are other potential negative effects to artificial sweetener usage, including gut flora disturbances, the promotion of psychological dependencies on sweets, and long term safety issues, but I think it’s important to be clear on where the science lies. So far as I can tell, according to the literature there isn’t an appreciable insulin effect from most sweeteners.

Still, some people anecdotally report an effect. As Jimmy Moore says, “The bottom line is to check your own blood sugar response and see how it impacts YOU.” Word. If you need to know (and most people don’t), testing yourself would be the way to do it.

Let me know if I’ve missed something, or come up short in my analysis. There’s a lot of stuff out there and it’s possible that I’ve overlooked something. And as always, I’d love to hear about your personal experiences with artificial sweeteners, especially regarding their effect on your weight loss/gain, insulin, appetite, and dietary success/failure. Let me know in the comment section!

P.S. If you’re new here and aren’t sure what all the fuss over insulin is about start here: The Definitive Guide to Insulin, Blood Sugar and Type 2 Diabetes (and you’ll understand it)

You want comments? We got comments:

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  1. Thanks for a very informative article, and to all those who mae comments

    Joan Mercantini wrote on February 6th, 2012
  2. This is an old thread but this topic is pretty interesting to me and I think my experience is different from the majority so I thought I’d post it.

    I am a low carb guy and have been for quite awhile. I also was a Diet Pepsi junkie and drank a lot of the stuff (around 250 ounces a day – not a typo). With lunch (salad with chicken and pork, pico de gallo, a little hot sauce and cheese) I’d typically have 100 oz of Diet Pepsi and I notice I’d be nearly passing out from a lack of energy an hour later. So I eventually quit the Diet Pepsi and switched to iced tea.

    The results were that my desire to sleep after lunch stopped occurring immediately and I ended up losing 14 lbs of fat and gained 6 lbs of lean muscle mass in 6 weeks. This was roughly 4 months ago and any cravings I had for sweet tasting beverages has completely gone away.

    Unfortunately I didn’t have my glucose meter back then so I don’t have any test results to see if I was experiencing a crash in blood sugar levels. I’m thinking of doing a test of this but it’s hard to raise any enthusiasm for the project since I’ve been so good since then and don’t want to mess up my success.

    So my personal experience is that large amounts of Diet Pepsi were doing something to me as my energy levels and weight changed as soon as I ditched the stuff. Whether it was the DP is impossible to say but it was the only thing that changed during this time period so I’m not certain what else it could be.

    Bob Johnston wrote on May 2nd, 2012
  3. I get cold sores from all all artificial sweeteners apart from xyilitol and Stevia.

    suzie wrote on May 5th, 2012
  4. Quoting Jimmy Moore in this otherwise well-written, informative article?? EPIC fail, dude. If Jimmy had any real clue, he wouldn’t have been on essentially the same diet since 2004 – still expecting some magically different result. Jimmy Moore is NOT paleo – he’s just adopted it to make money.

    CarbSanity wrote on August 24th, 2012
  5. We recently took my 11 yr old daughter and I off sweeteners. We have been off sugar for quite awhile and increased our artifical sweeteners. They created a huge Binge Eating Disorder in my daughter as well as affected her attention in school. I am in more control of my eating in recent years but think artifical sweeteners have been part of the problem all along in my binge eating disorder and bulimia. It;s really amazing actually-I didn’t believe the pediatrician but have now witnessed it first hand!

    Marcie wrote on October 4th, 2012
  6. In case you missed it, this paper
    analyzes the insulin cephalic response in rats to various sweeteners. (Yes, there is one).

    Mike wrote on December 8th, 2012
  7. Okay, once and for all, anything that even potentially causes insulin secretion to go UP will/should cause blood glucose to go DOWN. Because that is what insulin does!
    So to do “as Jimmy Moore says” and “check your own blood sugar response [to a given artificial sweetener] and see how it impacts YOU,” in the text of this article is probably not going to tell you much about the insulinogenicity of any given artificial sweetener unless you consume it by itself. Because all the other macronutrients we eat cause variable degrees of insulin secretion (carbs from fruit and vegetable sources, especially).
    So the popular idea that I read on paleo opinion sites all the time that artificial sweeteners cause “blood sugar” to go up are barking up the wrong tree! The only blood sugar we can measure outside of a research lab is glucose. And glucose does not go up in response to insulin secretion; only the consumption of glucose or starches or sugars that are converted to glucose in the body (amylose, fructose, et al.), none of which these artificial sweeteners are proported to do – they are proported to stimulate insulin secretion – DIFFERENT.
    If you’re going to talk about the science of this stuff, please get it right :)

    Dr. Maapkra wrote on December 23rd, 2012
    • * … fructose, etc.

      ‘et al.’ corresponds to personnel. (Brown, Jones, Smith et al.)

      danR wrote on August 6th, 2015
  8. I see several of these commenters are worried about artificial sweetener chemicals in their bodies but have no problem with drinking their coffee which is also full of chemicals. In fact it is reported that coffee has at least 200 carcinogens in its make up. perhaps worrying about the mountain instead of the mole hill would be more appropriate. Artificial sweeteners may be bad, coffee Way bad.

    Tommy wrote on February 10th, 2013
  9. I have slightly elevated blood sugar so I monitor it each morning when I wake up. I have a pretty good feel for what it should be each morning based on what I ate the previous day and how late at night I ate.

    However, once in a while I’ll forget to check my blood sugar until after I drink some coffee. I use either saccharin or xylitol in my coffee.

    I find that either one of these sweeteners will raise my blood sugar slightly – maybe 20 or 30 points. Not as much effect as a meal but there is definitely a small change in blood sugar from each sweetener.

    But, then again, maybe it’s the coffee that’s making the change. Hard to be certain.

    Knox wrote on February 12th, 2013
  10. Actually, there is noteworthy evidence aspartame does indeed affect insulin levels. Stevia was superior to both aspartame AND sucrose in this relatively well controlled study:

    WJ wrote on February 12th, 2013
  11. I have hypoglycemia. It is usually not a problem. I am not even that careful about what I eat. However, if I drink a diet soda, regardless of when I ate last, my blood sugar bottoms out in less than an hour. It makes me hungry enough to be nauseous every time. Perhaps it does not cause an insulin spike. Whatever the reason, the effect on blood sugar is very strong.

    Edgar Westmoreland wrote on March 13th, 2013
  12. Hi Mark,

    The sucralose section might need some updating if you read this study: Sucralose Affects Glycemic and Hormonal Responses to an Oral Glucose Load



    Petter Olsson wrote on October 7th, 2013
  13. I am a diabetic. I do not know if maybe it is some sort of allergic reaction or not but anything with aspartame makes my blood sugar soar. When I ran out of my insulin I could see 100 point spike after aspartame that would last all day. I do not have any reaction to Splenda (as of now).

    Rachael Jones wrote on October 21st, 2013
  14. I’m doing the low carb diet, so, when I drink something, I use sweeteners. Of course, I prefer sugar than sweeteners, maybe, this point also helps our desire for eating sweets (as the sweeteners are not so good, you will not very interested in their consumption). Anyway, even eating sweeteners some times (not often), I’ve been loosing a lot of pounds.

    Nathália wrote on November 3rd, 2013
  15. What a crock! The only non-sugar sweeteners that impact blood glucose and creates an insulin response are “sugar alcohols” like sorbitol, mannitol, and xylitol, and fructose. Less of an impact than sugar, but still significant. How do I know this? I’m a Type 1 diabetic on an insulin pump. I could drink only Diet Coke all day long and my glucose would be stable. And I have done this once in a while on busy days where I was concentrating on something and put off eating. If it rose, that would mean I would need to pump some insulin to offset it. Protein doesn’t produce an insulin response either, that’s why diabetics are encouraged to focus on meat and green veggies to keep our carb levels and insulin requirements low. Stop the panic! Artificial sweeteners are very helpful for controlling blood glucose and supporting weight loss, so I’m sick and tired of people trying to bash aspartame in particular, which has been clinically tested to death in double-blind studies by every developed country, and continually found to be safe except for those with specific genetic blood conditions. I have consumed at least 35,000 cans of diet soda over the last 30 years of having diabetes, and I’m in very good shape, thanks very much.

    Angela wrote on November 11th, 2013
  16. Mark, I have a question that came up after I read your comments about Splenda. I work in a lab and have access to free lab work. I want to drink a splenda flavored drink and then have my insulin level drawn and my blood sugar checked. I would do this several times and also have it drawn after drinking plain water. I need to know how long after I drink the Splenda or the water should I wait before having blood drawn? I can’t find an answer anywhere. Does your pancreas shoot it out immediately after ingestion, or does it take thirty minutes for optimal rise? Please tell me what you think or know about this. I really enjoy cooking with splenda and drinking water sweetened with Splenda. I use the liquid splenda which bypasses the problem of the dextrose filler. Thanks

    Jane Windham wrote on February 17th, 2014
  17. All you guys blaming binge eating on Splenda are out of your minds. As a bodybuilder, I am a HUGE advocate of Splenda.

    One of the most rewarding things you can treat yourself at the end of a hard day in the gym and office is a cup of calorie free lemonade or fruit punch.

    When I cut right before summer last year from 10% BF to 7% BF eating ~1200 calories a day as a 180lb male and the only thing entering my mouth was alternating chicken breasts and protein powder throughout the day, I gave myself 80 calories to drink a cup of KOOL-AID if I really earned it that day. Such a SWEET reward and was a huge motivator to keep feeding away on chicken all day long.

    Let me tell you, the fact that now I can drink that same kool-aid with 0 calories is an even better feeling, now I can put those extra 80-100 ‘kool-aid calories’ to better use with some barbeque sauce for my chicken next summer.

    Stop binging, and stop blaming splenda – your issues are psychological and much deeper than that.

    Zack wrote on February 18th, 2014
  18. I am from Brazil, and here we are lucky to have all sweeteners in liquid form (plus, cyclamate is legal here). This means they are diluted in distilled water (so, no extra carbs from maltodextrin, lactose or whatever), distributed in small flasks, and you put a few drops of the solution on whatever you want to sweeten. We have the powder as well, but most people prefer the liquid because it’s more practical. The only problem is that the only affordable ones are those based on the saccharin/cyclamate combo, which I can’t tolerate because of the bitter aftertaste. All others are outrageously expensive here, especially sucralose (about $5 USD for a 2-fl. oz. flask, less than $1 for a similar saccharin/cyclamate flask).

    What about stevia? Not very popular after Lydia Rodarte-Quayle, I suppose, but some people love it. Others, however, find it strongly bitter and very little sweet (if at all), and that includes me. Yuck!

    Goytá wrote on July 15th, 2014
  19. I don’t know about insulin releases, but both my wife and I are type 2 diabetics, she can control hers by diet, I inject 35 units of N morning and night. Now to the saccharin. We both test 4 times a day, in the morning after 8 hr fast the 2 hrs after each meal. Sometimes we have coffee in the morning anywhere from an hour to 10 minutes before testing. My wife has coffee every morning and I skip slot. That’s what got my attention. The wife’s sugar is high almost every day (120-170). Mine on the mornings I have coffee runs about the same as the wife’s. We use great value sweetner, saccharin according to the packaging, no creamer or flavoring. Now I tried the coffee without anything except the water, wife says no way, for about a week and my blood glucose levels stay below 110 every day. At the end of the week I returned to using the sweetner and the bgl went right back to 173. This is not the most scientific study by any means, but it convinced me. Like the man said test yourself.

    Sam Hill wrote on July 28th, 2014

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