Is Xylitol Safe?

xylitolWe continue on our journey of looking at different sweeteners today. Xylitol is on the menu today and so lets take a look at this substance and see what we discover. Xylitol is becoming popular in many foods and snacks. It’s a sweetener that is about as sweet as sucrose. It is found in nature but produced commercially chemically. On a personal note I think xylitol has what I can only describe as a “cooling” taste in my mouth, but that’s just me. So what else can we learn about xylitol. Study time!

Insulin and GI

In dogs after administration of xylitol and insulin response was seen. 1,2,3 Insulin did raise more with xylitol than with glucose. It is important to remember two big things from these studies; first is that these are dogs, second is these were infusions of xylitol rather than being ingested. Would ingested xylitol cause a greater response than glucose? I don’t know but it does appear to raise insulin.

After administration of xylitol, researchers measured a significant increase of insulin in the portal veins in man. 4

In another study 5 subjects were given 30gm glucose and 30mg xylitol (months apart) and their insulin responses as well as GIP and motilin. GIP (glucose-dependent insulinotropic peptide) is a hormone that increases insulin secretion. This action is greater when glucose is ingested rather than infused. Motilin does a number of things including stimulation of the motility of the gut. So in this study a solution of xylitol or glucose was given and they measured these factors. Insulin rose in both solutions but more so in glucose. In fact it was a very small increase with xylitol. GIP was not affected by xylitol but was by glucose. Glucose increased motilin and caused faster stomach emptying than xylitol. So what did the xylitol do you ask? Cause diarrhea. Yup it gave 3 of the 5 subjects the runs. The researchers attributed this to an osmotic difference. This is consistent with many reports that xylitol causes Montezuma’s revenge. The good part though is that it only happened that one time and after bowel evacuation the 3 volunteers had no more problems. 5 Very similar effects were seen in both men and rat subjects. 6

Another effect of xylitol, as mentioned above is that it can slow gastric emptying. This may be helpful to help a person feel full longer. A study looking at this gave subjects 25gm xylitol in solution at 10 AM. Others were given other sweet solutions such as fructose and sucrose. At 11 they were given a meal of eggs. The xylitol group maintained the food in their stomach for roughly 30min longer than the others groups. In another part of the study the same preloads were given and 1 hour later the subjects were allowed to eat at an “attractive buffet” (according to the researchers). Calorie intake was measured and the group that had 25gm preload of xylitol ate significantly less calories (690 +/- 45 with 25g xylitol vs 920 +/- 60 with water). 7

It think it’s important to keep this in context. These people were consuming 60 kcal before a meal to consume on average 230 kcal less. Now this would be a net reduction for the people in this study of 170kcal/meal. Not bad but the potential for diarrhea I’m sure would increase with that kind of dose if taken regularly.

So it appears that xylitol does have a very small impact on insulin and definitely the potential for an impact on your porcelain throne. It may also help you eat less when consumed about an hour before meals. What else can xylitol do?


Xylitol is touted as having beneficial properties on dental health, most especially with caries (cavities). One reviewer of articles believes this is due to increased saliva production from xylitol gum and candies rather than preventing bacteria from being able to metabolize the xylitol. 8 Saliva has chemicals that are responsible for tooth remineralization and health. Elderly folks who have chronic dry mouth are at increased risk of having caries. Some believe that streptococcus mutans (the bug responsible for laying down plaques and excreting acid) are responsible for caries and xylitol has been shown to stop this bug from doing it’s nasty deeds. 9,10 It’s possible that xylitol doesn’t interfere with the internal nutrient system in the individual teeth like sucrose does, but that is the topic of an entire article.

Don't let this be the result of poor dental health

Don’t let this be the result of poor dental health

An entire article looking at data has concluded that xylitol chewing gum is beneficial in preventing dental caries. 11 It should be noted it has to be done 3-5 times per day after meals and for at least 5 minutes. Chewing on one piece for 2 hours once a day might not do a thing. Another study done over 40 months in Belize showed that children who chewed xylitol gum had a significant reduction in caries over those who had xylitol-sorbitol combo and most definitely over sugar base gums. 12


Xylitol isn’t calorie free like some people may think. While sugar has close to 4kcal/gram, xylitol has 2.4kcal/gram. So if you’re using xylitol in cooking be aware that while you aren’t putting as many calories in that dish as sugar, you’re still putting calories into the food. So really you can only say that it is a lower calorie alternative to sugar, not a no calorie option.


There are actually nose sprays that one can use to help treat sinus problem and maybe even help resolve sinus and ear infections. Xlear is one company that makes such products. Because the xylitol helps disrupt bacterial plaques it is thought that they can help balance in the nose and ear. I’ve never tried them but if you have and had success I’d love to hear about it.


Some people have had problems with the gut after ingesting xylitol. As mentioned above xylitol can cause diarrhea and maybe fermentation can arise because it arrives to the colon pretty much untouched. There are no large trials that I know of showing adverse effects. Lack of evidence isn’t an indictment but for me xylitol goes into my book as once in a while probably ok but not regularly. This is a natural substance but you don’t get a lot of it naturally and there’s probably a reason for that. Sugar is also natural but really you don’t get a ton of it in nature all in one spot, at least in most areas. We humans condense it down and create abundance. If you are having ill effects but think you’re doing good for say your teeth, then you should reconsider using it. It’s never good to sacrifice one organ system for the other. Try to treat the whole system. Also, xylitol is toxic to your dog. Do not give xylitol to your dog!

If anyone has had any experience with xylitol please share down below. I love hearing anecdotal stories about how they affect different people.


1.Kuzuya, Takeshi, Yasunori Kanazawa, and Kinori Kosaka. “Stimulation of insulin secretion by xylitol in dogs.” Endocrinology 84.2 (1969): 200-207.

2.Kuzuya, Takeshi, Yasunori Kanazawa, and Kinori Kosaka. “Plasma insulin response to intravenously administered xylitol in dogs.” Metabolism 15.12 (1966): 1149-1152.

3.Hirata, Yukimasa, et al. “Blood glucose and plasma insulin responses to xylitol administrated intravenously in dogs.” Biochemical and Biophysical Research Communications 24.3 (1966): 471-475.

4.Berger, W., et al. “Insulin concentrations in portal venous and peripheral venous blood in man following administration of glucose, galactose, xylitol and tolbutamide.” Hormone and Metabolic Research 5.01 (1973): 4-8.

5.Salminen, Eeva K., et al. “Xylitol vs glucose: effect on the rate of gastric emptying and motilin, insulin, and gastric inhibitory polypeptide release.” The American journal of clinical nutrition 49.6 (1989): 1228-1232.

6.Salminen, Eeva K., et al. “Xylitol vs glucose: effect on the rate of gastric emptying and motilin, insulin, and gastric inhibitory polypeptide release.” The American journal of clinical nutrition 49.6 (1989): 1228-1232.

7.Shafer, Rex B., et al. “Effects of xylitol on gastric emptying and food intake.” The American journal of clinical nutrition 45.4 (1987): 744-747.

8.Alanen, Pentti. “Does chewing explain the caries-preventive results with xylitol?.” Journal of dental research 80.7 (2001): 1600-1601.

9.Beckers HJ. Influence of xylitol on growth, establishment, and cariogenicity of Streptococcus mutans in dental plaque of rats. CariesRes 1988;22(3):166-73.

10. Grenby TH, Phillips A, Mistry M. Studies of the dental properties of lactitol compared with five other bulk sweeteners in vitro. Caries Res 1989;23:315-9.

11.Burt, Brian A. “The use of sorbitol-and xylitol-sweetened chewing gum in caries control.” J Am Dent Assoc 137.2 (2006): 190-6.

12.Makinen, K. K., et al. “Xylitol chewing gums and caries rates: a 40-month cohort study.” Journal of Dental Research 74.12 (1995): 1904-1913.

Is Stevia Safe?

steviaWell we’ve hit the major artificial sweeteners in previous posts in this series. Today we look at a natural sweetener, stevia.

Stevia (stevia rebaudiana) is a sweetener that many people have been using for hundreds of years. It is native to Central America and South America. The leaves are around 40 times sweeter than sugar and the extract is about 300 times sweeter. It dissolves very quickly in and can have somewhat of a bitter aftertaste.

So we can’t call stevia an artificially sweet seduction since it is natural. But is it another sweet seduction or is it a winner to make things oh so wonderfully sweet?

Study Time!

In a study of rats, 0.5mg/kg of stevia lowered blood glucose levels in diabetic rats and glucose tolerance testing in normal rats. It also reduced insulin sensitivity in the diabetic rats and enhanced insulin secretion and insulin utilization.1

So even though insulin increased, sensitivity and utilization of the insulin was better. That is important to remember. If insulin merely goes up and isn’t used because of sensitivity, that is bad. If insulin goes up and is used, like in healthy individuals that’s ok. That’s the way it’s supposed to be.

In another study of diabetic induced rats, stevia was used to compare blood glucose levels with normal and diabetic controls. Subjects were fed 150mg/kg, 200mg/kg and 250mg/kg of stevia per day. Significant decreases in blood glucose were measured as well as non-significant decreases in body weight. Glimepiride (a diabetic drug which increases insulin secretion) was also used as a comparator. Glimepiride lowered blood glucose significantly more than stevia at all doses.2

In yet another rat trial, rats were made diabetic and given stevia, methi seeds, stevia with methi seeds, or glimepiride. They were followed for 60 days. Blood glucose decreased the greatest with glimepiride, next with methi and stevia combo, then methi alone, then with stevia alone. Stevia did create a significant effect on blood glucose by itself. 3

Another study shows that rats fed lots of fructose were able to decrease insulin resistance with a good ol dose of … guessed it, stevia.4

In an actual human study, subjects were given preloads of stevia, aspartame or sucrose before being fed a meal. 20 min after the meal blood was drawn and glucose and insulin measured. Compared to sucrose, aspartame and stevia produced less postprandial glucose levels. Stevia produced significantly lower insulin levels compared to aspartame and sucrose.

In another human study in subjects undergoing glucose tolerance tests, 5 grams of steavia leaves were given at 6 hour intervals for 3 days. The groups were separated into stevia and an aqueous arabinose solution. Stevia increased glucose tolerance and decreased glucose levels during the study.6

Other effects

Stevia appears to have some fertility effects, at least in rats. In one study a water decoction (a way of extraction by boiling chemicals from herbs or plants) was given to rats that were fertile. The infertility continued for 50-60 days after intake stopped. To the researchers no other effects were noticed. This was in females.7

In male rats in chronic (60 days according to the paper) administration produced,

“produced a decrease in final weight of testis, seminal vesicle and cauda epididymidis. In addition, the fructose content of the accessory sex glands and the epididymal sperm concentration are decreased. Stevia treatment tended to decrease the plasma testosterone level” 8

So these poor buggers not only had smaller testes but also less sperm and decreased testosterone. Not exactly a thrilling side effect.

Gut Flora

Stevia doesn’t appear to alter gut flora which is a good thing. The bacteria are able to alter it to steviol however that was the end of it. The tests were done with samples from human donors in vitro.9, 10  How’s about that for donating to science!? We can suppose that this would translate over to a real life human intestine but you never know in these types of studies. This information is promising though.

Blood Pressure

In a study in China, participants were given 500mg of stevia 3 times per day for two years vs placebo and blood pressure was measured. A significant decrease was noted after 1 week. The change was from 150 [7.3] to 140 [6.8] mm Hg; DBP, from 95 [4.2] to 89 [3.2] mm Hg. That’s not too bad. A side note from this study is that more people on placebo had a thickening of the left ventricle than people on stevia (34% vs 11.5% respectively) Quality of life scores were better with stevia. There was no difference in adverse effects between groups.11

Another study found no difference in blood pressure using 3 different doses of stevia, up to 15mg/kg/day.12 This for me would be the 500mg three times daily. The difference in this study is that it was dosed twice daily rather than three times daily. Is this enough to make a difference? I don’t know. I could develop all kinds of protocols for a study to look at these questions but the real question is does this harm you? In both of these studies no adverse effects were seen compared to placebo.

Some have claimed that stevia will raise epinephrine and cortisol. I can’t find any evidence to support this. If anyone has anything I’d love to see it. If that is true it would be a big ding against stevia but again I can’t find evidence to support it.

Stevia may also have oxalates in them which can be problematic for people with kidney stones made from the same substance. I can totally buy that the leaves have them, but I haven’t been able to confirm the extract.

Final thoughts….for now

It looks as though stevia is probably OK for use. If a person is having problems with infertility it may be best avoided. Some forms are sold with other fillers like maltodextrin so they may not truly be zero calories, although if you’re using 1 packet of the stuff it will be less than 4 calories. But if you’re using bulk you’ll have to take care like you would with sucralose, which you’ll never find in my house. Nasty stuff that is!

If you’re diabetic or worried about blood sugar then it appears stevia is beneficial, at least to some degree. Like I always say, try it out and see what happens to you because you and I are not the same people, and neither of us are rats.

You probably won’t find me using 500mg caps of stevia for blood pressure reduction either since I feel that a good diet and some movement will likely take care of that, but it won’t raise it either (unless you’re eating it with junk). From time to time you might see me sweeten something with it, but not regularly and certainly not in bulk. I like my testes the way they are thanks.


1.Chen, Tso-Hsiao, et al. “Mechanism of the hypoglycemic effect of stevioside, a glycoside of Stevia rebaudiana.” Planta medica 71.02 (2005): 108-113.

2.Sumon, M. H., et al. “Comparative efficacy of powdered form of stevia (Stevia rebaudiana Bertoni) leaves and glimepiride in induced diabetic rats.” Bangladesh Journal of Veterinary Medicine 6.2 (2008): 211-215

3.Rafiq, Kazi, et al. “Comparative efficacy of stevia leaf (stevia rebaudiana bertoni), methi seeds (trigonella foenum-graecum) and glimepiride in streptozotocin induced rats.” International Journal 2229 (2011): 7472.

4.Chang, J-C., et al. “Increase of insulin sensitivity by stevioside in fructose-rich chow-fed rats.” Hormone and metabolic research 37.10 (2005): 610-616.

5.Anton, Stephen D., et al. “Effects of stevia, aspartame, and sucrose on food intake, satiety, and postprandial glucose and insulin levels.” Appetite 55.1 (2010): 37-43.

6.Curi, R., et al. “Effect of Stevia rebaudiana on glucose tolerance in normal adult humans.” Brazilian journal of medical and biological research= Revista brasileira de pesquisas médicas e biológicas/Sociedade Brasileira de Biofísica…[et al.] 19.6 (1986): 771.

7.Planas, G. M., and J. Kucacute. “Contraceptive Properties of Stevia rebaudiana.” Science (New York, NY) 162.3857 (1968): 1007.

8.Melis, M. S. “Effects of chronic administration of< i> Stevia rebaudiana</i> on fertility in rats.” Journal of ethnopharmacology 67.2 (1999): 157-161.

9.Gardana, Claudio, et al. “Metabolism of stevioside and rebaudioside A from Stevia rebaudiana extracts by human microflora.” Journal of agricultural and food chemistry 51.22 (2003): 6618-6622.

10.Koyama, E., et al. “In vitro metabolism of the glycosidic sweeteners, stevia mixture and enzymatically modified stevia in human intestinal microflora.” Food and Chemical Toxicology 41.3 (2003): 359-374.

11.Hsieh, Ming-Hsiung, et al. “Efficacy and tolerability of oral stevioside in patients with mild essential hypertension: a two-year, randomized, placebo-controlled study.” Clinical therapeutics 25.11 (2003): 2797-2808

12.Ferri, Letícia AF, et al. “Investigation of the antihypertensive effect of oral crude stevioside in patients with mild essential hypertension.” Phytotherapy Research 20.9 (2006): 732-736.

Neotame: The Newest Artificially Sweet Seduction

sugar lipsSucralose, saccharin, aspartame, acesulfame potassium and now neotame are all artificially sweet substances that cause problems for many. Today we discuss the last, neotame.

Neotame (kind of sounds like the Matrix) is essentially aspartame with the addition of a 3,3-dimethylbutyl group which is supposed to stop it from being broken down to phenylalanine and thus safe for people with phenylketonuria. I don’t mean to be an alarmist but this stuff isn’t exactly benign. Here are two links to the chemical properties and handling warnings regarding 3,3-dimethylbutyl;

It is flammable and an irritant to the skin and eyes and respiratory system. Much of the data regarding this substance has been published by industry and not independent researchers. Here is a short review of a review looking at some of those studies. I will post the link so you can take a look at it too if you want.

In a study of 19 healthy males and 12 healthy males in a three way crossover study no  “chemical, haematological, physiological or subjective findings were recorded“.1

In another study 12 people of each sex were given 20mg caps of neotame daily and was well tolerated, according to the paper. The only difference seen was greater availability in women than men. So maybe with long term ingestion women would be more affected.

In another larger study of 76 men and 75 women, neotame was dosed at 0.5mg/kg and 1.5mg/kg bodyweight for 13 weeks. The researchers concluded there was no difference between treatment groups and placebo. Headaches in this study were not significantly different between groups either.1

Another looked at non-insulin dependent diabetics. Neotame was given 3 times a day in capsules at the same doses as the above mentioned study. Plasma glucose and insulin were unaffected. Flu like syndrome, headache and sinusitis were reported with more in the placebo group reporting problems than the test group.1

As far as metabolism goes, 4.9 percent of the total dose given to subjects was excreted as -dimethylbutyl)-L-aspartic acid, so some of the molecules are obviously being cleaved. Could this lead to an alteration of healthy gut flora? It certainly could be possible. No studies yet though to confirm that. Not to mention that the Panel looking at this stated that “there was extensive excretion of neotame metabolites in faeces” which would indicate again the possibility of gut flora alteration over time.

You can read the rest of the paper with the link below. I again have to repeat myself that these studies were not long term and can’t really tell us much about the population at large.

According to one news report neotame is also now being used in cattle feed because the price of molasses is too high. 2 Sweetos apparently is also increasing the amount of weight on the cattle. 3,4 So an artificial sweetener is increasing weight in cattle apparently because of increased feeding.

Side Effects

Many of the side effects of neotame are the same as aspartame which makes sense since neotame is just aspartame with that 3,3-dimethylbutyl group attached to it. Neurologic effects are possible because of the phenylalanine, as discussed with aspartame. I can imagine that  it could effect mood or anxiety. I know my stress goes up when I chew gum with aspartame in it. Seizures have been reported in mice with electroshock potentiation.5 I don’t know how many people are receiving electroshock therapy regularly but the concern would be somebody who is predisposed to seizure activity in the first place.

I also think it worth noting that this substance was approved by the FDA for use in the food supply while things like Stevia could only be allowed as a supplement. I know not all things natural are healthy per se but the things the FDA pulls are just crazy anymore. Neotame is also made by Nutrasweet which is a former part of Monsanto. Dr. Mercola has an interesting chart of people who worked for Monsanto and in the US government.3 Things like this make approvals like neotame and others make sense.

I’ve personally not ever tried neotame…at least to the best of my knowledge. This goes into my category of probably best avoided. It’s becoming increasingly difficult to avoid such things as they creep their way into the food supply. The easiest thing to do is avoid processed foods. If you have stress, anxiety, seizures or other unexplained ailments and you partake of these or think you do, try eliminating them from your diet and give some naturally sweet fruit a shot. Apples taste really good once you train your tongue to taste things as they are and not artificially inseminated with junk. For some having things like neotame every once in a while will probably not adversly affect them at all. I’m just trying to avoid any potential complications all together.

Next up we’ll be talking about some other alternatives like stevia or xylitol.

Do you have any experiences with neotame or any other sweetener? Let me know in the comments.


1.Aguilar, Fernando, et al. “Neotame as a sweetener and flavour enhancer1 Scientific Opinion of the Panel on Food Additives, Flavourings, Processing Aids and Materials in Contact with Food.” (2007).




5.Maher, Timothy J., and Richard J. Wurtman. “Possible neurologic effects of aspartame, a widely used food additive.” Environmental Health Perspectives 75 (1987): 53.

Foods with Sugar

Here is a quick video discussing some foods with sugar in them and how much sugar is there. This isn’t anything novel but I thought it’d be fun to just show a few things and their sugar content. By the way, I know I say tomato soup in the video and a can of tomato paste shows up but both can have added sugar so just enjoy!


Does Acesulfame Potassium Spike Insulin?

sugar lipsWe’ve now looked at sucralose, saccharin and aspartame. Next up is acesulfame potassium. It too is commonly found in soft drinks, tooth paste, medications and I frequently see it in protein powders to sweeten up a post workout shake. But what effect does acesulfame potassium (ace-k) have on insulin or anything else. Well you guessed it, we’re going to find out.

I’ve largely ignored rat studies up till now, but the evidence with this one isn’t as abundant as others so we gotta go with what we have. So lets get dirty.

Rats were given an infusion of ace-k and blood levels were drawn at intervals after the administration of the dose. A dose of 150mg/kg of bodyweight were infused. Lets stop right there. I weigh about 106kg. For me that would be the equivalent of almost 16gm of ace-k. That’s an insane amount of an artificial sweetener and if you ate that much a day I’m sure you wouldn’t be feeling very well. I’ve read that Coke Zero has about 50mg of ace-k per can so to get the equivalent the rats were getting that’s like me drinking 320 cans at one time. If the taste of the Coke didn’t kill me then I’m sure hyponatremia probably would. I know there is probably a conversion that one would need to use to actually figure out what that dose would be in a human and it would be less, but still a lot . Anyway, these rats received a very large amount of ace-k and their insulin levels went up by around double. No increase in blood glucose was seen. 1 So this study supports the notion that if you consume unholy amounts of ace-k your insulin is likely to go up.

In an in vitro study on rat pancreases, islet cells (the ones responsible for insulin release) were bathed in solutions of ace-k. Insulin concentrations were measured at different times after introduction into the ace-k media. Insulin went up. 2 It’s important to remember though that this setting was in vitro, not a real life situation. So these results may or may not translate over to the real clinical realm.

What about humans?

In a human study, diet soda (sucralose and ace-k sweetened) or soda water was given to 22 healthy subjects 10 min before an oral glucose test. Researchers looked at glucose, insulin and GLP-1. Remember that GLP-1 is a hormone that can increase insulin release. Measurements were taken at 30 min intervals for 3 hours after the glucose test. As expected all three rose, the only difference was the GLP-1 rose signifcantly more in those who had the diet soda than those who had soda water.3 In this particular study the GLP-1 didn’t seem to affect insulin. Could this increase in GLP-1 cause problems over time for people? For some people it most certainly could and for others it probably wouldn’t make any difference. The real answer is we just don’t know, and a person can only truly know by testing how it affects themself.

In a feeding study participants who were mild diabetic or borderline diabetic were given meals sweetened either with sugar or aspartame and ace-k. Blood glucose, insulin, triglycerides, FFA, and C-peptides were measured after ingestion of the meals. Blood glucose rose significantly more in the group that had sugar than aspartame and ace-k. Insulin also rose more in the sugar group. 4 This was done over four meals on different days. Again this study shows that, at least in combo with aspartame, ace-k doesn’t seem to affect insulin or blood sugar. Now again this is in a very short term study and doesn’t tell us much about chronic ingestion of ace-k.

From some anecdotal articles I’ve read about people trying to lose weight it has caused problems in some and not in others. One claims that it only hampers the weight loss of “normal people” and very lean athletes. 5


As with the other artificial sweeteners one of the common complaints associated with ace-k is headache. I can say that I do see a lot of migraine medications go out of the pharmacy fairly regularly. I of course can’t claim that it is due to artificial sweeteners like ace-k but I often wonder if people got artficial sweeteners out of their diet if headaches wouldn’t subside at the same time.

In one study of rat feces, researchers noted that anaerobic bacteria were prevented from fermenting glucose with ace-k, cyclamate and saccharin. 6 This doesn’t show conclusively a change in gut bacteria, but it could lead to a change over time which could lead to other problems. What I’m trying to say is that it hasn’t been well studied (at least to my knowledge) and so we can only speculate as to what’s really going on in the gut. Again if you feel like crap after eating something crappy like an artificial sweetener, then stop. Every once in a while, if it causes no problems, then in my opinion it’s like having a nice ice cream (without artificial crap). Ice cream isn’t exactly health food is it? But it sure is tasty and if you give up ice cream forever because it’s not good for you that’s your choice not mine. But I don’t have ice cream every night.

I think if I was ingesting ace-k on a regular basis and was having problems like weight loss or if I was diabetic and having sugar control issues, then I would stop ingesting it for a while and see what would happened. Ultimately the only person responsible for your health is you and if this article has convinced you that ingesting ace-k is ok and won’t cause any problems, then I invite you to reread the article.

I’d love to hear any experiences you’ve had with ace-k or any other  artificial sweeteners.


1.Liang, Yin, et al. “The Effect of Artificial Sweetener on Insulin Secretion 1. The Effect of Acesulfame K on Insulin Secretion in the Rat (Studies In Vivo).” Hormone and metabolic research 19.06 (1987): 233-238.

2.Liang, Yin, et al. “The effect of artificial sweetener on insulin secretionII. Stimulation of insulin release from isolated rat islets by Acesulfame K (in vitro experiments).” Hormone and metabolic research 19.07 (1987): 285-289.

3.Brown, Rebecca J., Mary Walter, and Kristina I. Rother. “Ingestion of diet soda before a glucose load augments glucagon-like peptide-1 secretion.” Diabetes Care 32.12 (2009): 2184-2186.

4.Fukuda, Masahiro, et al. “Aspartame-Acesulfame K-containing Low-Energy Erythritol Sweetener Markedly Suppresses Postprandial Hyperglycemia in Mild and Borderline Diabetics.” Food science and technology research 16.5 (2010): 457-466.


6.Pfeffer, M., S. C. Ziesenitz, and G. Siebert. “Acesulfame K, cyclamate and saccharin inhibit the anaerobic fermentation of glucose by intestinal bacteria.” Zeitschrift für Ernährungswissenschaft 24.4 (1985): 231-235.

Does Aspartame Spike Insulin?

sugar lipsWell we’ve looked at sucralose and insulin as well as saccharin. What about aspartame? It is one of the most commonly used artificial sweeteners and you’ll most likely find it in soda and other sweetened snacks along with acesulfame potassium. So lets take a look at aspartame and sort out what may or may not be correct.

First lets take a quick look at what aspartame is. Aspartame contains phenylalanine, an amino acid, aspartic acid and methanol. That’s right, methanol or wood alcohol. 1 Methanol gets converted into formaldehyde and formic acid, which are both toxic. Two reviews of the safety of aspartame have concluded that this isn’t a problem at the doses typically consumed by the public. 2,3  We’ll talk more about the safety in a bit. Lets now focus on insulin.

In one study of 6 males administration of aspartame had no effect on insulin levels. 4

In another study aspartame was given in meals to 16 normal individuals and they looked at several hormones after ingestion. I think this part is funny. In the study the researches claim,

Serum insulin decreased slightly and serum glucose increased slightly over the course of all test procedures; both responses were statistically significant in nearly all tests”

They then go on to say,

” We found no effect of any of the test meals on serum cortisol, GH, insulin, or glucose…” (emphasis added)

So they either had a typo or forgot that the results were signficant. It is most likely that the decrease in insulin was from the morning meal and the levels were just decreasing back to baseline, and the authors come to the same conclusion. 5

In one study of 48 people, researchers gave sucrose or aspartame over a four month period in crossover. No differences were seen in the subjects with regards to insulin. 6

In another study looking at preload meal compared sucrose, stevia, and aspartame sweetened cream chease and crackers with tea on insulin levels. Blood samples were taken post meal and found that the sucrose and aspartame samples elevated insulin the same after 30 min while the stevia group was significantly lower. This study doesn’t look strictly at aspartame vs sucrose and I think it’s useful in this case because calories were also consumed with the sweeteners as would be done in a real life situation. Aspartame didn’t raise insulin anymore than the sucrose, but it was the same. 7

In a hospital study, diabetic subjects were given aspartame and researchers looked at…you guessed it glucose and insulin, as well as triglycerides and HDL. No change was seen. 8

Another study looked at pretty much the same thing (I feel like I’m beating a dead horse here) but also compared saccharin to aspartame in a drink. No differences were noted with the exception of a small increase in the AUC (total insulin exposure) with the aspartame over saccharin. 9 The researchers claimed there was probably no clinical significance to this. Maybe not and maybe so. Who knows for sure?

Just like the last two articles discussed, these studies weren’t done over a long term (3 years or more) and to be able to make any strong conclusions about aspartame’s true effect on insulin or glucose cannot be made based on these studies. It just looks like if you have something sweetened with aspartame every once in a while, the effect on insulin and glucose in and of itself probably isn’t significant. If you’re eating carbs though with these sweeteners, which isn’t unlikely, are the results different? It’s possible but we just don’t know without the research as a whole. If you check blood glucose and notice that it went down after decreasing aspartame ingestion then you would have your answer.

Aspartame in my opinion, just like other artificial sweeteners is not all that pleasant tasting. It is very sweet, but yeah….not pleasant for me. Ice cream sweetened with aspartame is an abomination. It tastes so much better with good ol sucrose. And yes I do have ice cream from time to time because hey, it’s ice cream!  It is very often found in diet sodas. Sodas are probably the biggest sources of it followed by yogurt and powdered soft drinks, at least according to the Nutrasweet company. 10

But what about other health concerns?

According to one epidemiologic study there was no significant findings for adverse events or toxicity. 11 Another study shows that at doses of 75mg/kg/day of aspartame for 24 weeks with no adverse effects significant over placebo. 13 A quick Google search will quickly dispel those studies with anecdotal evidence. I’m not a person to discount anecdotal evidence, in fact I think it’s important, especially if the N=1 is you. But the studies are important too so I want to review a review that you can access online:

First recall that aspartame gets broken into 3 parts in the body; phenylalanine, aspartic acid, and methanol. Phenylalanine plays an important role in neurotransmission as it is a precursor for DOPA, dopamine, epinephrine and norepinephrine. It also competes for a ride on a protein called neutral amino acid transporter (NAAT). This transports not only phenylalanine but others as well. Large amounts of one amino acid will out compete the others for a spot on the NAAT and stop the balance that is normally attained. In this case with increased phenylalanine in the brain, levels of catecholamines can be increased. Tryptophan can also be displaced by too much phenylalanine and cause lack of serotonin in the brain. This can lead to sleep problems and and appetite problems. Aspartame may also bind to NMDA receptors and cause neurologic damage.

Aspartic acid may play a role as an excitatory nuerotransmitter and may play a role in the problems caused by ingesting aspartame. Additionally methanol, as discussed earlier can be converted to formaldehyde and formic acid. According to the researchers fibromyalgia, spasms, shooting pains, numbness in the legs, cramps, vertigo, dizziness, headaches, tinnitus, joint pain, depression, anxiety, slurred speech, blurred vision or memory loss have been attributed to aspartame.12

Headache's a problem? Ditch Aspartame

Headache problems? Ditch Aspartame

Much of the anecdotal evidence I’ve seen revolves around headaches. I’ve also read reports about gut problems and other neurologic problems that sound similar to fibromyalgia symptoms. I haven’t come across anything that shows there is an effect on gut bacteria. It wouldn’t surprise me if it did, but I can’t say that it does.

So should you avoid aspartame? Probably. Every once in a while probably won’t do anything if you’re otherwise healthy but I can’t recommend it regularly. The taste is gross and because of that and that companies would taint the oh so wonderful goodness of ice cream with it is enough for me…..and the possible health detriments too of course.

What are your stories? I’d love to hear about any experiences you’ve had with aspartame.


1.Humphries, P., E. Pretorius, and H. Naude. “Direct and indirect cellular effects of aspartame on the brain.” European Journal of Clinical Nutrition 62.4 (2007): 451-462.

2.Magnuson, B. A., et al. “Aspartame: a safety evaluation based on current use levels, regulations, and toxicological and epidemiological studies.” CRC Critical Reviews in Toxicology 37.8 (2007): 629-727.

3.Butchko, Harriett H., et al. “Aspartame: review of safety.” Regulatory Toxicology and Pharmacology 35.2 (2002): S1-S93.

4.Møller, Svend E. “Effect of Aspartame and Protein, Administered in Phenylalanine‐Equivalent Doses, on Plasma Neutral Amino Acids, Aspartate, Insulin and Glucose in Man.” Pharmacology & toxicology 68.5 (1991): 408-412.

5.Carlson, Harold E., and Jayendra H. Shah. “Aspartame and its constituent amino acids: effects on prolactin, cortisol, growth hormone, insulin, and glucose in normal humans.” The American journal of clinical nutrition 49.3 (1989): 427-432.

6.Spiers, Paul A., et al. “Aspartame: neuropsychologic and neurophysiologic evaluation of acute and chronic effects.” The American journal of clinical nutrition 68.3 (1998): 531-537.

7.Anton, Stephen D., et al. “Effects of stevia, aspartame, and sucrose on food intake, satiety, and postprandial glucose and insulin levels.” Appetite 55.1 (2010): 37-43.

8.Okuno, Giichi, et al. “Glucose tolerance, blood lipid, insulin and glucagon concentration after single or continuous administration of aspartame in diabetics.” Diabetes research and clinical practice 2.1 (1986): 23-27.

9.Horwitz, David L., Michael McLane, and Peter Kobe. “Response to single dose of aspartame or saccharin by NIDDM patients.” Diabetes Care 11.3 (1988): 230-234.


11.Magnuson, B. A., et al. “Aspartame: a safety evaluation based on current use levels, regulations, and toxicological and epidemiological studies.” CRC Critical Reviews in Toxicology 37.8 (2007): 629-727.

12.Humphries, P., E. Pretorius, and H. Naude. “Direct and indirect cellular effects of aspartame on the brain.” European Journal of Clinical Nutrition 62.4 (2007): 451-462.

13.Leon, Arthur S., et al. “Safety of long-term large doses of aspartame.” Archives of internal medicine 149.10 (1989): 2318.

Artificially Sweet Seductions – Saccharin

sugar lipsIn the last post we looked at sucralose and it’s effect (or lack of) on insulin. It also has an effect on gut microbes. But sucralose isn’t the only artificial sweetener. Today lets look at saccharin and see what it can do.

Saccharin was discovered in 1878 by a chemist who when sitting down for dinner and noticed a sweet taste after a day at the lab. After tasting the substance he went back to the lab and began tasting everything to find the source. Serendipity led to the “discovery” of saccharin. And it was sweet.

It didn’t take a genius to figure out the implications and soon it began to be added to make things sweet. So the question is how does it affect blood sugar or insulin.

In one study participants, while fasting “sipped, and washed out their mouths with eight taste solutions (sucrose, saccharin, acetic acid, sodium chloride, quinine hydrochloride, distilled water, starch, and sodium glutamate) for 45 s and spat them out again”. 1 Insulin levels raised significantly with the sucrose and the saccharin solutions, but not the others. Blood glucose was not affected during any of the solutions. This study says that there is a potential to raise insulin with saccharin.

In another study different drinks were given to participants with either saccharin, aspartame or non-sweetened drinks and researchers looked at insulin levels.2 No significant difference in insulin levels were seen.

In another study similar to the first one listed, no differences were seen in any case with insulin. 3

In another study researchers gave sucrose or starch sweetened with saccharin in equal caloric amounts and measured insulin levels, glucose levels, triglycerides and glucose excretion. After 6 weeks and crossover for the two groups of another 6 weeks there was no difference. 4

It doesn’t look as though saccharin has a lot of influence on insulin, at least in these human studies. Again it would be good to have a long term study to really look at the impact on insulin and blood sugar. What about weight?

In a study with rats, when added to the diet, saccharin and aspartame increased weight gain. 6 But what about in humans?

To be honest I can’t find randomized controlled trials that show saccharin ingestion and weight increase. There are epidemiological studies that show associations but we all know these do not equal causation. There are many studies in rats that seem to show weight gain like the one I just mentioned above but I don’t always transpose what happens in rats to what happens in humans.

What has saccharin been found to do? In rats it appears to inhibit some digestive enzymes. 6 It also makes stomachs hemorrhage and causes iron deficiency anemia in rodents. 7 It should be noted these affects are in high doses, levels we humans probably wouldn’t get. Another study shows that saccharin reduces good bacteria in rats. 8 This is similar to what was reported with sucralose. This could be very problematic. While I haven’t seen any experiments in humans for this phenomenon I don’t doubt this is something that could translate over into humans.

The problem with most of these studies is that they’re short term. Long term nutritional studies are hard to do. A significant decrease in good gut bacteria probably won’t show up as anything over a 6 week period. Over a 6 year period or longer though that could be problematic. The gut is definitely a crucial part of overall health and disrupting good bacteria may lead to many problems from digestive to autoimmunity.

People have reported nausea and other gut dysfunction and have anecdotally correlated that with saccharin ingestion. It’s important to note that saccharin has a sulfa component to it, which is a major cause of drug allergies in many people. This could be part of the reason why nausea seems to be a problem. It could be a low level intolerance or allergy to this sulfa component. If you have a known sulfa allergy it would be good to avoid saccharin.

The FDA almost got a ban on saccharin back in the 70’s but it got defeated. They were concerned with bladder cancer in rodents. While a little saccharin here and there probably isn’t at all a problem for many, many others might feel its effects quickly. Ultimately the only way to know is to experiment with yourself but my advice is overall stay away from artificial sweeteners. Saccharin has a nasty aftertaste anyway.


1.Just, Tino, et al. “Cephalic phase insulin release in healthy humans after taste stimulation?.” Appetite 51.3 (2008): 622-627.

2.Horwitz, David L., Michael McLane, and Peter Kobe. “Response to single dose of aspartame or saccharin by NIDDM patients.” Diabetes Care 11.3 (1988): 230-234.

3.Teff, Karen L., John Devine, and Karl Engelman. “Sweet taste: effect on cephalic phase insulin release in men.” Physiology & behavior 57.6 (1995): 1089-1095.

4.Cooper, P. L., M. L. Wahlqvist, and R. W. Simpson. “Sucrose Versus Saccharin as an Added Sweetener in Non‐insulin‐dependent Diabetes: Short‐and Medium‐term Metabolic Effects.” Diabetic medicine 5.7 (1988): 676-680.

5.Feijó, Fernanda de Matos, et al. “Saccharin and aspartame, compared with sucrose, induce greater weight gain in adult Wistar rats, at similar total caloric intake levels.” Appetite (2012).

6.Lok, Eric, Frank Iverson, and David B. Clayson. “The inhibition of urease and proteases by sodium saccharin.” Cancer letters 16.2 (1982): 163-169.

7.Okamura, T., E. M. Garland, and S. M. Cohen. “Glandular stomach hemorrhage induced by high dose saccharin in young rodents.” Toxicology letters 74.2 (1994): 129-140.

8.Mallett, Anthony K., Ian R. Rowland, and Carol A. Bearne. “Modification of rat caecal microbial biotransformation activities by dietary saccharin.” Toxicology 36.2 (1985): 253-262.

Disclaimer: All info on this website is for education purposes only. Any dietary or lifestyle changes that readers want to make should be done with the guidance of a competent medical practitioner. The author assumes no responsibility nor liability  for the use or dissemination of this information. Anyone who chooses to apply this information for their own personal use does so at their own risk.