Altered processing of sweet taste in the brain of diet soda drinkers

Abstract

Artificially sweetened beverage consumption has been linked to obesity, and it has been hypothesized that considerable exposure to nonnutritive sweeteners may be associated with impaired energy regulation. The reward system plays an integral role in modulating energy intake, but little is known about whether habitual use of artificial sweetener (i.e., diet soda consumption) may be related to altered reward processing of sweet taste in the brain. To investigate this, we examined fMRI response after a 12-hour fast to sucrose (a nutritive sweetener) and saccharin (a nonnutritive sweetener) during hedonic evaluation in young adult diet soda drinkers and non-diet soda drinkers. Diet soda drinkers demonstrated greater activation to sweet taste in the dopaminergic midbrain (including ventral tegmental area) and right amygdala. Saccharin elicited a greater response in the right orbitofrontal cortex (Brodmann Area 47) relative to sucrose in non-diet soda drinkers. There was no difference in fMRI response to the nutritive or nonnutritive sweetener for diet soda drinkers. Within the diet soda drinkers, fMRI activation of the right caudate head in response to saccharin was negatively associated with the amount of diet sodas consumed per week; individuals who consumed a greater number of diet sodas had reduced caudate head activation. These findings suggest that there are alterations in reward processing of sweet taste in individuals who regularly consume diet soda, and this is associated with the degree of consumption. These findings may provide some insight into the link between diet soda consumption and obesity.

Neural responsivity during soft drink intake, anticipation, and advertisement exposure in habitually consuming youth

“…In contrast, obese versus lean individuals show less striatal activity during palatable food intake (12)(13)(14), which may delay meal termination if individuals are seeking the previously experienced pleasure from food intake. In support, objectively measured food intake beyond needs correlated positively with activity in attention and gustatory regions when anticipating palatable food receipt (15), and striatal response during intake correlated negatively with frequency of consumption of foods similar to those in the scan (16,17). Collectively, data demonstrate differences in neural responsivity to food stimuli during anticipation versus intake as a function of weight status and habitual intake, suggesting that regular consumption of energy-dense, palatable foods leads to hyper-responsivity of reward valuation regions to cues that signal potential intake and hypo-responsivity of reward regions during consumption.…”

Diet Drink Consumption and the Risk of Cardiovascular Events: A Report from the Women’s Health Initiative

“…26 Another study investigating the functional magnetic resonance imaging response to sucrose (a nutritive sweetener) and saccharin (a nonnutritive sweetener) in diet soda drinkers versus non-diet soda drinkers found alterations in the reward processing of sweet taste in individuals who regularly consume diet soda. 27 An alternative explanation for this association could be confounding by dietary patterns or incomplete adjustment for confounders. In a recent study, diet beverage consumers defined as having a healthy diet had a lower risk of metabolic syndrome.…”

Le goût sucré, de l’enfance… à la dépendance ?

“…La mise en bouche d'un stimulus sucré et calorique entraîne l'activation des cortex gustatifs et de régions impliquées dans le circuit de la récompense ; de plus, plusieurs études ont montré que la mise en bouche d'édulcorants ou de glucides non sucrés pouvait aussi entraîner l'activation de ce circuit [4,5,25,26].…”

“…Cela confirme le rôle de l'amygdale dans la représentation de la valeur d'un aliment en lien avec son utilité biologique, et suggère qu'être exposé à la saveur sucrée sans apport de calories entraîne une dégradation de la capacité de la perception sucrée à prédire l'arrivée de calories au niveau de l'amygdale. Les résultats d'une autre étude montrent aussi que la consommation régulière d'édulcorants pourrait être associée à une altération de la valeur de récompense de la saveur sucrée, calorique ou non [26]. Un autre travail montre que chez les adolescents normopondéraux, la consommation fréquente de crème glacée entraîne une sous-activation du striatum en réponse à la mise en bouche de milkshake [22].…”