Key Topics Covered
For clarification, we are specifically covering artificial sweeteners – not natural sweeteners or sugar alcohols.
And exploring whether or not these raise insulin or blood sugar levels and if so, how much that would actually matter.
Acute Mechanisms
- One proposed mechanism that is quite common is that – “the ingestion of artificial sweeteners results in the release of insulin from the pancreas, due to the sweet taste of these sweeteners being mistaken for glucose. This increases the levels of insulin in blood eventually leading to decreased receptor activity due to insulin resistance.”
- This logic stems from a known mechanism called the cephalic phase insulin response – where oral exposure to sugar or carbohydrates triggers an early low-level rise in insulin.
- But that is just a mechanistic theory. We will explore the actual outcomes seen in the literature later on.
Considerations of These Mechanisms
- If somebody’s insulin raised, without glucose actually coming, and glycogen levels were low, would this lead to a hypo?
- Is it dose-dependent? E.g. if one can of Diet Coke caused this, what would 5 do?
- A study that mentioned this mechanism found that those living with diabetes who had used artificial sweeteners for the longest had the highest levels of insulin resistance.
- But that doesn’t really mean anything due to all the other variables – So I’d be taking those findings with a grain of salt.
Chronic Mechanisms
- One example was touched on in that previous logic – the increased levels of insulin in the blood could lead to a decrease in receptor activity.
- Rebuttal to that – High insulin levels don’t necessarily cause insulin resistance. Otherwise, we would see high carbohydrate intake being linked with diabetes as an independent variable, which we don’t.
- It’s only linked with diabetes in the context of higher calorie intake and/or higher levels of body fat and/or lower levels of activity etc.
- Another example of a mechanism that is a bit more nuanced is regarding the influence on our microbiota.
- If artificial sweeteners change the gut microbiome, that could play a role.
Research Looking At Acute Outcomes
Research Showing Changes
- Some small-scale research has actually found changes in BGLs due to artificial sweetener intake.
- One example is a 2013 study where they gave 17 subjects either water or sucralose prior to an oral glucose tolerance test, in a crossover design.
- They found that blood glucose levels increased slightly more after sucralose with a 4.8mmol vs 4.2mmol increase.
- They also found insulin went 20% higher.
- But I wouldn’t read too much into that.
- The sample size is small. BGLs fluctuate a lot too. I wouldn’t be shocked if that study was repeated with water vs water and they found differences.
- I have also seen reviews of this study saying things like “Scientists believe sucralose causes insulin increase by triggering sweet taste receptors in the mouth — an effect known as cephalic phase insulin release.” But if that’s true – why did BGLs also increase?
Research Showing No Changes
- In one study of 22 subjects trialing 400mg aspartame, 135mg saccharin, or an unsweetened drink – there was no difference in insulin or BGLs.
- A 2020 systematic review involving 26 studies, including thousands of participants found no acute differences in BGLs or insulin.
Impact on Microbiome
- The logic is that regular intake changes the balance of our gut bacteria which could make our cells resistant to the insulin we produce, leading to both increased blood sugar and insulin levels.
Research
- A 2022 study involving 120 participants consumed very high dosages of artificial sweeteners, including saccharin, every day, for 2 weeks.
- They found some changes in the microbiome via stool samples, and it looked like there was some impaired glucose tolerance.
- In that study saccharin was the one that had the largest difference.
- They also specified that the dosage used was lower than what had been considered the “acceptable daily limit” even though it was still higher than a normal intake. (ADI is equivalent to 3.7 cans of diet soft drink for Saccharin – which is actually quite low in comparison to others).
- On the one hand, I wouldn’t read too much into that, particularly since the body of evidence hasn’t consistently had findings like that. But it’s also a reason why saccharin has lost popularity.
- A 2021 review found a neutral impact of artificial sweeteners on BGL levels, indicating not much change in insulin resistance.
Microbiome Summary
- Overall, the microbiome aspect is complex.
- Sucralose and saccharin appear to alter the microbiome.
- On the one hand, it seems unlikely this impact is large, given the lack of link with most health conditions under controlled circumstances.
- But I also wouldn’t completely rule out any level of impact whatsoever.
Summary
- Artificial sweeteners definitely do not impact blood glucose levels or insulin in the short term. That can be said with a lot of confidence.
- The longer-term outcomes are less clear.
- It is unlikely to have a large impact (if at all). Otherwise, we would see different outcomes in that 2021 systematic review.
- But I wouldn’t say with 100% confidence that there is definitely zero impact.
Relevant Links / Resources
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Studies Mentioned