Functional Connectivity Underlying Cognitive Control and the Influence of Weight Status

Objectives: Veterans are at high risk for PTSD, and prior research has shown that PTSD is commonly comorbid with eating disorders, especially binge eating.Trauma can cause excessive excitation via glutamate, exacerbating trauma-related symptoms.In previous research, we observed significant reduction in PTSD symptoms from treatment with the low glutamate diet, which eliminates free (non-bound) glutamate and emphasizes nutrient-dense foods.This study aimed to examine whether or not the low glutamate diet could reduce eating disorder symptoms, and if so, whether improvements in PTSD mediate this effect in veterans with Gulf War Illness.Methods: Fifty-six veterans were recruited as part of an ongoing phase III clinical trial.PTSD severity was assessed using the Post-Traumatic Checklist (PCL-5) and eating disorder attitudes and binge eating were measured via the Eating Disorder Diagnostic Scale (EDDS) before and after the diet.Dietary adherence was evaluated using an excitotoxin food frequency questionnaire (FFQ).Pre-and post-diet comparisons were assessed using paired t-tests or Wilcoxon Signed Rank tests, and Spearman tests were used to analyze correlations.PROCESS was used to assess potential mediation of PTSD.Statistical analyses were conducted in R with significance set at p 0.05.Results: On average, the veterans were 57 (7) yrs old, 55% were female, 73% were Caucasian, and they had an average BMI of 31 (7).Dietary adherence was high, with significant reductions in excitotoxin FFQ scores (p < 0.001).Median (IQR) values were significantly improved for both PTSD symptoms (26 [32] to 15 [24], p< 0.001), and ED symptoms (16 [12] to 8 [13], p< 0.001).Reports of binge eating also significantly dropped (30% vs. 5%, p< 0.001).High dietary adherence correlated with reductions in eating disorder attitudes (rs 0.32, p0.03) and binge days (rs0.28,p0.05).PTSD improvement correlated with reduced eating disorder attitudes (rs0.30,p0.04); however, mediation analysis found no evidence that PTSD reductions mediated the relationship between excitotoxin exposure and eating disorder symptoms.Conclusions: These findings suggest that binge eating and PTSD may be comorbid due to both being influenced by dysregulation of glutamatergic neurotransmission, rather than PTSD causing disordered eating.