Non-nutritive sweeteners (NNS) like sucralose have always been hot topics for debate in the nutrition world. The controversy is not just about whether they are “good” or “bad”—it is about the complexity behind each sweetener and the diverse ways they may impact health. Importantly, these sweeteners are largely heterogeneous. Their effects can differ substantially depending on the specific compound and the health outcome being measured. Lumping all NNS together oversimplifies the science and does little to help individuals make informed choices.

Sucralose

Recent attention has focused on sucralose (commonly known as Splenda) and its potential role in altering blood sugar responses. It is critical to evaluate sucralose independently from other sweeteners and to consider its effects in specific contexts—such as fasting, with meals, or in people with and without diabetes.

When Sucralose Is Consumed Alone

Current evidence suggests that when sucralose is ingested by itself (without accompanying carbohydrates), it does not appear to significantly raise blood glucose in healthy individuals or those with diabetes (Pepino et al., 2013; Sylvetsky et al., 2016).

Sucralose and Glycemic Response to Meals

However, the story changes when sucralose is consumed alongside a meal. Several studies have found that sucralose may increase the glycemic response to eating, especially in people who are not habitual users of NNS or who have obesity (Pepino et al., 2013; Romo-Romo et al., 2018; Dalenberg et al., 2020). The magnitude and consistency of this effect, however, remain debated.

Proposed Mechanisms

Researchers have proposed a few mechanisms by which sucralose might influence blood sugar regulation:

• Sweet-taste Receptor Signaling in the Gut: Sucralose may activate sweet-taste receptors in the gastrointestinal tract, potentially increasing glucose absorption after a meal (Dalenberg et al., 2020).
• Hormonal Changes: Some studies have observed changes in hormones like GLP-1 and insulin after sucralose ingestion, which could alter glucose metabolism (Pepino et al., 2013). This may actually be due to the sweet-taste receptor signaling in the gut.
• Inflammation: There is preliminary evidence that sucralose might increase markers of inflammation, though findings are not consistent (Romo-Romo et al., 2018).
• Gut Microbiome: Sucralose may affect the gut microbiota in some individuals, potentially influencing glucose metabolism, but results are highly variable (Suez et al., 2014).

Limitations and Practical Takeaways

It is important to note that many of these studies were not specifically designed or adequately powered to determine whether sucralose has a substantial impact on blood sugar control or long-term health. More well-designed clinical trials are needed before drawing strong conclusions.

For now, people struggling with blood glucose control may reasonably choose to avoid sucralose—provided it is not replaced with regular sugar or caloric sweeteners, which are known to cause a much larger glycemic response, and carry a much higher risk for adverse health outcomes.

Whereas for other folks, this currently does not need to make it to the top of your priority list for dietary adjustments. This is especially true if you find sucralose in foods that are otherwise contributing to an overall healthful dietary pattern.

All the best,

Kevin Rogers, RDN, LD

Founder | Redesign Nutrition

References

Dalenberg, J. R., Patel, B. P., Denis, R., Veldhuizen, M. G., Nakamura, Y., Vinke, P. C., … & Small, D. M. (2020). Short-term consumption of sucralose with, but not without, carbohydrate impairs neural and metabolic sensitivity to sugar in humans. Cell Metabolism, 31(3), 493-502.e7. https://doi.org/10.1016/j.cmet.2020.01.014

Pepino, M. Y., Tiemann, C. D., Patterson, B. W., Wice, B. M., & Klein, S. (2013). Sucralose affects glycemic and hormonal responses to an oral glucose load. Diabetes Care, 36(9), 2530-2535. https://doi.org/10.2337/dc12-2221

Romo-Romo, A., Aguilar-Salinas, C. A., Brito-Córdova, G. X., Gómez-Díaz, R. A., Vilchis-Valverde, D., Almeda-Valdes, P., & Cuevas-Ramos, D. (2018). Sucralose decreases insulin sensitivity in healthy subjects: A randomized controlled trial. The American Journal of Clinical Nutrition, 108(3), 485-491. https://doi.org/10.1093/ajcn/nqy152

Sylvetsky, A. C., Rother, K. I., Brown, R. J. (2016). Artificial sweetener use among children: Epidemiology, recommendations, metabolic outcomes, and future directions. Pediatric Clinics of North America, 63(5), 1145-1158. https://doi.org/10.1016/j.pcl.2016.06.009

Suez, J., Korem, T., Zilberman-Schapira, G., Segal, E., & Elinav, E. (2014). Non-caloric artificial sweeteners and the microbiome: Findings and challenges. Gut Microbes, 6(2), 149-155. https://doi.org/10.1080/19490976.2015.1017700