Researchers Dispute Loss of Sensory Function Among AN Patients

Fear of food-related stimuli
may be the true problem.

In anorexia nervosa (AN), the sensation of taste and smell are thought to be altered and hunger and pain are believed to be muted. Furthermore, AN-related body image distortion is assumed to obscure the patient’s sense of wasting. These deficits are then, in turn, believed to facilitate self-starvation. However, the results of a small study at the University of Haifa dispute this concept of sensory-perceptual deficit in AN patients (Am J Clin Nutr 2012;95:272).

Dr. Galit Goldzak-Kunik and colleagues studied 30 adolescents, 15 of whom were first-episode, hospitalized AN patients and 15 matched healthy controls. All subjects responded to 5 basic tastes and to odors of foods and nonfoods. The teens were also asked to estimate their body size (using several different manual and qualitative methods). Cold, pain, and auditory and visual processing were also assessed and compared.

On most tests, AN patients did not differ from healthy controls. They were better at recognizing odors, but less successful in central auditory processing and in some measures for assessing size and shape. They may have also been more sensitive to cold. Body image dissatisfaction among the AN patients was not related to inaccurate estimations of body size.

Dr. Goldzak-Kunik and co-workers concluded that there is no systematic sensory-perceptual deficit among AN patients and specifically, no deficits in smell and taste. The authors suggest that the few between-group differences might have been actually been due to fear of food-related stimuli or comorbidity.