Glucose-loaded dopamine transporter is associated with mood altering effect of sweet foods and control over eating sweets

Abstract

ABSTRACTDopamine transporter (DAT) mediates reuptake of extracellular dopamine into presynaptic neurons. We investigated the effects of glucose loading on striatal DAT in healthy young adults who underwent18F-FP-CIT positron emission tomography (PET) scans, and sweet taste questionnaire (STQ). Thirty-five healthy subjects were enrolled in this study. Each subject visited the institution three times, for three brain PET scans (two18F-FP-CIT PET scans after the infusion of glucose or placebo and one18F-Fluorodeoxyglucose PET scan). All subjects underwent STQ, 12-item self-reporting to evaluate subjects’ reactions to eating sweets, craving for sweets and degree of control over eating sweet foods (STQ 1: sensitivity to mood altering effect of sweets, and STQ 2: impaired control over eating sweet foods). We created Bayesian models separately with STQ 1, and STQ 2 as predictors, with DAT availability and brain glucose uptake as a dependent variable. From caudate, glucose-loaded DAT availability was significantly higher than placebo-loaded DAT availability, and from putamen, glucose-loaded DAT availability showed the higher trend than placebo-loaded DAT availability. STQ was positively associated with glucose-loaded DAT availability. The effect of STQ markedly overlapped with zero on placebo-loaded DAT availability, and brain glucose uptake. In conclusion, the change of striatal DAT availability after glucose loading is associated with the vulnerability to sweet foods. This may indicate that individuals with higher DAT availability after glucose loading experience a rapid clearance of synaptic dopamine after consuming sweet foods, potentially leading to a desire for additional sweet foods.