Chronic non-nutritive sweetener and free sugars consumption alters decision-making and risk-taking in young healthy adults

Background Non-nutritive sweeteners (NNS) are increasingly used as sugar substitutes to enhance food palatability without adding calories. Although their metabolic effects are well documented, their cognitive and socio-emotional correlates remain unclear. Objective This study investigated the associations between chronic NNS consumption, cognitive performance, and socio-emotional behaviors in healthy young adults, controlling for free sugars intake to isolate substance-specific effects. Methods A total of 291 French adults aged 18–30 years completed five computerized tasks assessing decision-making and emotion regulation: the Iowa Gambling Task (IGT), the Game of Dice Task (GDT), the binary dictator game, the Prisoner’s Dilemma, and the Emotion Regulation Questionnaire (ERQ). Daily NNS and free sugars intakes were estimated using quantitative food frequency questionnaires (q-FFQs). Logistic mixed-effects regression models were used to examine the effects of NNS and free sugars intake on choice probabilities. Results Higher NNS intake tended to be associated with selecting an advantageous yet risky option relative to its non-risky counterpart during the final experiential risk block of the IGT (OR = 1.34, 95% CI [1.06, 1.69]; p = 0.063, Bonferroni-corrected). Under explicit risk (GDT), NNS intake was also significantly positively associated with selecting the riskiest option over the moderate risky option (OR = 1.35, 95% CI [1.12, 1.62]; p = 0.006, Bonferroni-corrected). Higher free sugars intake was negatively associated with selecting a disadvantageous and non-risky option relative to its risky counterpart during the final IGT block (OR = 0.78, 95% CI [0.66, 0.94]; p = 0.028, Bonferroni-corrected). No consistent association was observed for free sugars in the GDT. Free sugars intake was negatively associated with cognitive reappraisal (p = 0.027) and expressive suppression (p = 0.028), whereas NNS intake tended to be positively associated with cognitive reappraisal only (p = 0.062). Neither NNS nor free sugars intake had significant effect on altruism or cooperative behavior. Conclusion Chronic NNS and free sugars consumption were differentially associated with decision-making under explicit and experiential risk, as well as with emotion regulation, but not prosocial behaviors. These results provide novel insights into how dietary sweeteners may influence risk-related cognitive and emotional processes in healthy young adults.