Restrictive early development eating disorders, such as mental anorexia and selective or avoidance food disorder (Tase), could be associated with structural changes in the brain in affected children, reveals a new study published in Mental Health Nature and led by Clara Moreau, researcher at the Azrieli research center in the Sainte-Justine and Deputy Professor The University of Montreal.
What is selective and/or avoidance food disorder?
Clara Moreau
Credit: CHU Sainte-Justine
Better known under its English acronym ARFID (“Avoying/Restrictive Food Intake Disorder”), the tase consists in limiting food intake or eating only certain types of food, but without desire to lose weight and in the absence of a distorted body image. It generally appears during early childhood and would be the result of loss of interest in food, sensory hypersensitivity encouraging to avoid certain textures or tastes, or even a fear of the consequences of eating (eg vomit, choke).
Thanks to brain image analyzes obtained by magnetic resonance (MRI) of children aged 7 to 13 with mental anorexia or a severe tase, the team of researchers highlighted major brain alterations, specific to each of these two eating disorders. If part of these changes is attributable to weight loss, in particular to this crucial period of brain development, the study also shows effects of the disease. Good news: the data collected at different stages of care suggest that these alterations would at least be partly reversible.
This is the first study to document the impact of the tase on cerebral morphometry, and one of the few to assess that of mental anorexia with early development, a less frequent form of this disorder which appears before puberty.
An impact beyond weight loss
By comparing the brains of children with mental anorexia to those of children living with a tase, Clara Moreau shows that the impact of these two disorders is not only linked to thinness. Indeed, although all the children of the study which had a food disorder had a low body mass (BMI) index (<16), the brain alterations were clearly different between the two groups. "In anorexic children, we have observed a significant and generalized thinning of the cerebral cortex," explains the main researcher. This phenomenon had recently been documented in adolescent and adult populations with anorexia, which suggests a significant impact on the brain, regardless of age at the time of diagnosis. " About half of this effect would be attributable to rapid weight loss.
Conversely, in children with a tase, the thickness of the cerebral cortex remains intact, but there is a decrease in intracranial volume and gray matter. Despite a similar BMI, these alterations would not be linked to thinness in these children. “Tase often starts earlier and more progressively than anorexia; It is possible that the brain and metabolism manage to adapt to the food restriction, which could explain the absence of effect on the thickness of the cortex in these children, ”says the researcher.
Support brain recovery to prevent relapses
The study also shows that the brain can recover with weight gain. By comparing children according to their recovery stage, scientists noted that structural differences tend to fade as the BMI increases. “It is very encouraging, as it suggests that a complete recovery is possible when recovery occurs in young age and the number of relapses is limited.”
To better understand the evolution of brain functions over the recovery, Clara Moreau and her team will continue their work from a longitudinal perspective by integrating functional brain imagery. The professor intends to set up a cohort of children followed at the Clinique des Disorders de CHU Sainte-Justine and take advantage of the fine of the Imagine center of this same establishment. “We know that about a third of hospitalized young people for mental anorexia relapse in the year following their leave. Could this be linked to incomplete brain recovery? And if so, could we predict the risk of relapse in order to better support the most vulnerable young people? ”
About the study
The study covers 290 children from 7 to 13 years old, including 124 suffering from mental anorexia and 50, of a severe tase.
The article “Neuroimaging Insights Into Brain Mechanisms of Early-Oset Restrictive Eating Disorders” is published in Nature Mental Health by Clara A. Moreau et al. The study benefited from the financing of several organizations, including the National Institute of Mental Health, the Fondation de France, the National Research Agency, the Pasteur Institute and the German Research Foundation.