Hormonal
Higher body mass index (BMI) is associated with increased striatal dopamine tone in humans, as indicated by the differential displacement of low-affinity PET tracers ([11C]raclopride) compared to high-affinity tracers ([18F]fallypride).
This research suggests that higher body weight is linked to higher baseline (tonic) dopamine levels in the brain's reward centers, which may blunt the response to specific rewards. While this paper does not offer a direct intervention, it implies that weight loss might normalize dopamine tone, potentially improving reward sensitivity. However, the causal direction (does weight cause high dopamine or vice versa?) remains unproven in this cross-sectional study.
Given that [18F]fallypride has greater binding affinity to dopamine type-2 receptors than [11C]raclopride, which is more easily displaced by endogenous dopamine, our results suggest that adiposity is positively associated with increased striatal dopamine tone.
Why this rating
Controlled inpatient study with standardized diet and fasting, using two distinct PET tracers to resolve previous methodological conflicts.
Source
Striatal dopamine tone is positively associated with body mass index in humans as determined by PET using dual dopamine type-2 receptor antagonist tracers
Valerie L. Darcey et al. · medRxiv · 2023
DOI 10.1101/2023.09.27.23296169
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