The Change of Dopamine Transporter After Glucose Loading Is Associated With an Individual's Attitude Toward Sweet Foods in Healthy Young Males

The dopamine transporter (DAT) mediates the reuptake of extracellular dopamine into presynaptic neurons. We investigated the effects of glucose loading on the striatal DAT in healthy young adults who underwent ¹⁸F-FP-CIT PET scans and completed a sweet taste questionnaire (STQ). Thirty-five healthy participants were enrolled in this study. Each participant visited the institution three times for three brain PET scans (two ¹⁸F-FP-CIT PET scans after the infusion of glucose or placebo and one ¹⁸F-Fluorodeoxyglucose PET scan). All participants underwent the 12-item self-reporting STQ to evaluate their reactions to eating sweet foods, cravings for sweet foods, and degree of control over eating sweet foods (STQ 1: sensitivity to the mood-altering effect of sweet foods, and STQ 2: impaired control over eating sweet foods). In the caudate, glucose-loaded DAT availability was significantly higher than placebo-loaded DAT availability, and in the putamen, there was a trend toward higher DAT availability following glucose loading. The STQ was consistently positively related to glucose-loaded DAT availability, not with placebo-loaded DAT availability. In conclusion, changes in striatal DAT availability after glucose loading suggest an association with attitudes toward sweet foods in healthy young males. This may indicate that individuals with higher DAT availability after glucose loading experience rapid clearance of synaptic dopamine after consuming sweet foods, potentially leading to a desire for additional sweet foods.