Human brain responses to the artificial sweetener sucralose and sucrose in the presence of flavour modifier.

Abstract

Objectives: There is a significant need to reduce sugar in food. We can replace sugar with non-nutrient sweeteners; however, they need to be desirable. Previously, we found adding a flavour modifier to a taste can result in neural super-additivity that could drive enhanced pleasure. It is not known if adding a flavour modifier to a non-nutrient sweetener could affect brain activity in the same way.

Methods: Healthy adults (N = 48, Mean age 26 yrs.) participated. We examined the neural effects of adding a flavour modifier to the non-nutrient sweetener sucralose (SLM) and the neural effects of sucrose vs sucralose. We examined whole brain data and the ROIs insula, pre- and postcentral gyrus, identified from a meta-analysis on brain responses to sweet tastes.

Results: Super-additive neural effects to SLM were in the mid/inferior temporal gyri, pre- and post-central gyri and parietal areas at the whole-brain level, p < 0.05 Family Wise Error corrected threshold. Superior frontal gyrus activity correlated with SLM pleasantness. There were no whole brain differences including reward-related differences between sucrose and sucralose. We did find greater ROI somatosensory activity (p = 0.01) for sucrose vs sucralose.

Discussion: We provide the first evidence that adding a flavour modifier to a non-nutrient sweetener reveals synergistic neural activity in brain areas associated with taste sensation, intensity, attention, perception and multisensory integration. Modifiers added to sweeteners could help consumers switch to healthier options and producers reduce the amount of sugar in foods. Future studies should examine if neural super-additivity effects can be used to predict subsequent consummatory behaviour.