Sucralose: a bad gut feeling for athletes

Oct 4, 2018 4:09:59 PM
2 min read

It is no secret that in our Western culture far too much sugar is consumed, with negative consequences such as obesity, diabetes, heart failure, elevated cholesterol and blood pressure, Alzheimer's desease,... That is why different alternatives to sugar have been developed to give products a sweet taste without the resulting calories and health disadvantages.

One of those alternative artificial sweeteners is sucralose, which is 650 times sweeter than sugar but contains only a fraction of the calories.

There has been a lot of controversy about sucralose, but it is considered safe for consumption, with migraine as the only recognized side effect.

But what we really should have a look at as an athlete, is the effect of sucralose (and other artificial sweeteners) on our intestines.

The microbiome: an athletic organ

More and more research emphasizes the importance of the bacteria in our intestines (the ' microbiome') for optimal health and performance.

The number and type of bacteria in our intestines have a great influence on how our body breaks down carbohydrates, fats and proteins for energy production, and on inflammation, the immune system and a whole range of other physiological processes.

And there lies the problem.

Artificial sweeteners such as sucralose, but also Acefulsame K, aspartame and saccharine have a negative influence on the bacteria in our intestines.

For the average person this might not be such a big deal, but for an athlete, whose performance depends among other things on the good digestion of carbohydrates, this is a tremendously important fact.

Intestinal discomfort is high on the list of unwanted effects for an athlete, and sucralose seems to have a negative impact on the number of intestinal inflammations worldwide.

A study (1) showed a dramatic increase in the number of irritable bowel syndrome cases worldwide after the commercialization of sucralose:


  Further studies (2) (3) showed that artificial sweeteners not only had a negative impact on the intestinal bacteria, but that this also caused glucose intolerance, a tragedy for athletes who must be able to optimally digest carbohydrates, but also a health risk that can cause diabetes.

So what's the big deal?

We consider this important findings, even for the average person, and we would recommend to drastically reduce the amount of artificial sweeteners, just like we would advise to cut down on sugar.

However, for an athlete this is even more important: the role of your gut on your performance is not to be underestimated. Athletes therefore even have a different kind of microbiome than non-athletes (4), suggesting that the intestines adapt to deliver top performance, like for example your muscles.

Research of Asker Jeukendrup confirms these findings (5).


Even though artificial sweeteners such as sucralose are considered "safe", however, we believe that they have no place in the diet of an athlete, and maybe not even in the diet of a health conscious person.

Therefore, you will also find no artificial sweeteners in our range, and we prefer to use natural sweeteners such as stevia or thaumatin.



  1. Etiology or inflammatory bowel disease: a unified hypothesis, World J Gastroenterol. 2012 APR 21; 18 (15): 1708 – 1722.
  2. A bitter aftertaste: unintended effects of artificial sweeteners, Cell Metabolism 20, Nov. 4, 2012
  3. J. Suez et al, artificial sweeteners induce glucose intolerance by altering the gut microbiota, Nature, doi: 10.1038/nature13793, 2014
  4. The microbiome of professional athletes differ from that of more sedentary subjects in composition and particular at The functional metabolic level
    Wiley Barton1, 2.3, Nicholas C Penney4, 5, Owen Cronin1, 3, Isabel Garcia-Perez4, Michael G Molloy1, 3, Elaine Holmes4, Fergus Shanahan1, 3, Paul D Cotter1, 2, Orla O'Sullivan1, 2
  5. Jeukendrup AE. Training the gut for athletes. Sports Medicine.


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