Psychology and wellbeing - Sense Of Taste Different In Women With Anorexia

A new study, published in the journal Neuropsychopharmacology, finds that women with anorexia have distinct differences in the insula, a part of the brain that is important for recognizing taste.

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.

Dr. Angela Wagner of University of Pittsburgh and Dr. Walter H. Kaye of the University of California measured, using functional magnetic resonance imaging (fMRI), the brain activity of 32 women, 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.)

In response to 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.

According to Kaye, 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. This could shed light on why individuals with anorexia avoid normally "pleasurable" foods, fail to appropriately respond to hunger and are able to lose so much weight.

"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 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, according to Kaye.

Source: University of California, San Diego, News Center