Anorexia may be linked to brain size
New research suggests that the size of a person’s brain may put them at an increased risk for developing an eating disorder, such as anorexia. Specifically, people with a bigger brain may be able to starve themselves, which can act as a predicting factor for the disorder.
Researchers at the School of Medicine at the University of Colorado looked at 19 adolescent females with anorexia nervosa, and 22 adolescent girls without the disorder. They used MRIs to study the brain volume of all the girls, and found that the ones with anorexia had a larger left orbitofrontal, right insular and bilateral temporal gray matter compared to the females without the disorder. A comparison study was also done in adults with anorexia, and researchers found that these women also had larger orbitofrontal cortex and insula volumes compared to healthy women.
The insula is the area of the brain that is active when we taste food, and the orbitofrontal cortex tells us when to stop eating. Researchers say that this brain pattern could encourage people with eating disorders to stop eating before they have eaten enough, compared to healthy people. In addition, the negative association between a pleasant taste and the heightened ability to stop eating could trigger food avoidance in people with anorexia.
The right insula is also responsible for our perception of body image, which is distorted in people with anorexia. The larger volume of the insula may explain why people with anorexia think they are fat even when they are underweight.
Researchers conclude that while environmental factors can trigger anorexia, there likely are biological mechanisms that also can make a person more likely to develop the disorder as well.