High-fat taste challenge reveals altered striatal response in women recovered from bulimia nervosa: A pilot study

Abstract

Objectives Individuals with anorexia nervosa (AN) and bulimia nervosa (BN) tend to have disordered thinking and eating behaviours in regards to fat containing foods. This is the first study to investigate neuronal pathways that may contribute to altered fat consumption in eating disordered patients. Methods We used functional magnetic resonance imaging (fMRI) to compare responses to a high-fat cream stimulus, water, and a non-caloric viscous stimulus (CMC) to control for response to viscosity in individuals recovered from AN (N = 15), BN (N = 14) and a healthy control sample (CW, N = 18). Results An interaction analysis (ANOVAR) comparing the three groups (AN, BN, CW) and the three conditions (cream, CMC, water) revealed significant differences in the left anterior ventral striatum (AVS). A post hoc analysis displayed a higher magnitude of response for the contrast cream/water in BN compared to AN or CW and for the contrast CMC/water in BN compared to AN. Conclusions BN showed an exaggerated AVS response for the cream/water contrast in comparison to AN or CW. Moreover, BN showed an exaggerated AVS response for the CMC/water contrast in comparison to AN. These findings support the possibility that BN have an altered hedonic and/or motivational drive to consume fats.

Altered intrinsic functional brain architecture in female patients with bulimia nervosa

“…Specifically, patients with bulimia nervosa showed exaggerated response to food stimuli in the striatum and OFC 5 and reduced amygdala response to disgusted facial expressions. 4 Altered activity in the ACC and OFC has been observed in patients with bulimia nervosa during impulse-control tasks, which has been associated with self-regulatory deficits 12,13 (i.e., an inability to inhibit impulses in favour of a delayed reward).…”

“…8 Dysfunction in these regions has been proposed to comprise key neural mechanisms underlying altered reward and emotional sensitivity, 2,[4][5][6][7] interoceptive deficits 3 and self-regulatory difficulties, 12,13 especially in response to eating-and body-related stimuli. These multidimensional pathological features collectively induce the body image distortion and binge eating and purging behaviours characteristic of bulimia nervosa.…”

“…We hypothesized that patients with bulimia nervosa would show abnormal topological properties in functional brain networks and that the functional disturbances would be apparent in the cortical and subcortical regions involved in reward and emotional processing, sensorimotor and visual perception, and interoception, based on potential relevance of these neural functions to bulimia nervosa. [2][3][4][5][6][7][8][9][10][11][12][13][14][15] We also examined the behavioural/symptom correlates of these network properties.…”

Neural signature of food reward processing in bulimic-type eating disorders

“…Studies examining gustatory processing have found that the reactivity of the reward system is positively related to binge eating episodes in patients with BED (Wang et al, 2011), whereas in BN, both increases (Radeloff et al, 2014) and decreases (Frank et al, 2006;Bohon and Stice, 2011) in brain responses within the reward network have been observed. Furthermore, general reward processing (i.e.…”

Advances in the neurobiology of eating disorders

“…Although people recovered from anorexia nervosa and bulimia nervosa both report preferring water to high fat/high viscosity solutions, their patterns of brain activation differed in that people with bulimia nervosa had greater activation to a high fat/high viscosity solution in the anterior ventral striatum, whereas people with anorexia nervosa had less activation in the same area [43]. This suggests that the encoding of reward to food taste differs across the two forms of disorder.…”