The Groundbreaking Study
In September of 2007, the news media publicized a study done by by University of Pittsburgh and University of California, San Diego, which was later published in the journal Neuropsychopharmacology. This study examined the connection between anorexia and taste sensations, and implied that women who previously struggled with anorexia have a different sense of taste than women who did not. As there were only 32 women in the study, further research is necessary to ensure that this relationship holds true. Yet, how did they figure it out?
The researchers gathered 16 women who had previously struggled with anorexia and 16 women who had not, but had similar backgrounds. They then gave each woman a glass of water and a glass of sugar water, and examined the action in their brains through FMRI (functional magnetic resonance imaging) technology. They found that the women who had had anorexia had significantly less activity in the insula, or taste-pleasure section of the brain, while drinking both drinks. Even the previous anorexics who said that they enjoyed the taste of the sugar water had this reduced activity, relative to the brain activity of the women who had never had anorexia.
What Do These Results Mean?
According to Walter Kaye, one of the researchers in the study, there are a few possible explanations of the results. It could be that people who have had anorexia in the past actually experience fewer taste sensations than the people around them. Alternatively, they may experience anorexia recognize the taste, but merely have fewer positive emotional reactions to the sense of taste than a non-anorexic. In fact, people who have experienced anorexia may find normally pleasurable food somewhat aversive, possibly because of the emotional negative toward food that developed when they were going through anorexia.
Alternatively, it could be that anorexia does not cause a change in taste sensations at all. Instead, it could be that certain people are prone to developing anorexia due to their lack of interoception, especially regarding food. Interoception is the way that a person experiences physiological sensations within the body. This lack of interoception would lead to anorexics' ability to avoid responding to hunger pangs more easily than others, as well as their ability to view their body as "fat" no matter how much weight they lose, ignore the symptoms of malnutrition that crop up while suffering from anorexia, and resist changing their attitudes toward food during therapy for eating disorders.
Further research into this alleged connection between anorexia and taste sensations is necessary to pinpoint exactly how to interpret these results. The research should focus on whether anorexia causes changes in taste sensations, or whether a dulled sense of taste is one of the causes or risk factors of anorexia.