Women with anorexia have distinct differences in the insulta - the specific part of the brain that is important for recognizing taste, a new study by University of Pittsburgh and University of California, San Diego researchers has found. Appearing in Neuropsychopharmacology, the study also implies that there may be differences in the processing of information related to self-awareness in recovering anorexics compared to those without the illness - findings that may lead to a better understanding of the cause of this serious and sometimes fatal mental disorder.
In the study, led by Angela Wagner, from the University of Pittsburgh School of Medicine, the brain activity of 32 women was measured using functional magnetic resonance imaging. The research team looked at images of the brains of 16 women who had recovered from anorexia nervosa and 16 control subjects. They measured their brains' reactions to pleasant taste (sucrose) and neutral taste (distilled water). The results of the study are the first evidence that individuals with anorexia process taste in a different way than those without the eating disorder.
With both the sucrose and water, imaging results showed that women who had recovered from anorexia had significantly reduced response in the insula and related brain regions when compared to the control group. These areas of the brain recognize taste and judge how rewarding that taste is to the person. In addition, while the controls showed a strong relationship between how they judged the pleasantness of the taste and the activity of the insula, this relationship was not seen in those who had recovered from anorexia.
The researchers say that it is possible that individuals with anorexia have difficulty recognizing taste, or responding to the pleasure associated with food. Because this region of the brain also contributes to emotional regulation, it may be that food is aversive, rather than rewarding.
"We know that the insula and the connected regions are thought to play an important role in interoceptive information, which determines how the individual senses the physiological condition of the entire body," said coresearcher Walter H. Kaye. "Interoception has long been thought to be critical for self-awareness because it provides the link between thinking and mood, and the current body state." This lack of interoceptive awareness may contribute to other symptoms of anorexia nervosa such as distorted body image, lack of recognition of the symptoms of malnutrition and diminished motivation to change, concluded Kaye.
Pro-Ana: Still Dying To Be Thin
Anorexia Linked To Emphysema
Source: University of California - San Diego