New study finds differences between obese and anorexic brains
Differences discovered between anorexic and obese brains could lead to a better understanding and treatment of both diseases.
A recent study conducted by the University of Colorado School of Medicine, has found evidence to suggest that the reward system of the brain may function differently for women with anorexia, when compared to women who are clinically obese. The results of the study conducted by the US-based university suggest that women with anorexia have sensitised ‘brain reward circuits’ and comparatively, obese women’s reward circuits are desensitised. This provides a new perspective on anorexia treatment methods.
According to Dr Guido Frank, a member of the developmental brain research programme at the University of Colorado, and the assistant professor director of the department:
“It is clear that in humans, the brain’s reward system helps to regulate food intake [but] the specific role of these networks in eating disorders such as anorexia nervosa and, conversely obesity, remains unclear.”
Informing eating disorder treatment methods
The results of the study have been published in detail in the Neuropsychopharmacology journal online, including details of the purpose of the study, its findings, and in particular, the link identified between brain reward systems, sensual responses and learned associations: “this paradigm involves learning the association between conditioned visual stimuli and unconditioned taste stimuli”. The findings are likely to inform anorexia treatment methods, as continued research into the complexities of anorexia reveals more about the condition, and the development of effective support strategies.
In total, 63 women participated in the study, which used functional magnetic resonance imaging (fMRI) to test the responses of participants to liquids that tasted either sweet or non-sweet. The responses differed between anorexic and obese women, as well as the control group of women, who were identified as a being a healthy weight. Researchers found that the reward systems in the brains of anorexic participants were higher than the neural activity of participants who were obese.
A similar study conducted in 2008, found that there was a link between the chemical dopamine, associated with pleasure, its signalling within the brain, and obesity. According to Dr Emmanuel Pothos, who was a researcher in the study:
"Baseline dopamine levels were 50% lower and stimulated dopamine release was significantly attenuated in the brain reward systems of [the] obesity-prone."
According to Pothos, a number of studies have produced evidence which suggests that when eating food, more dopamine is released by the brain, to the circuits that: “mediate the pleasurable aspects of eating”. In addition, when the body does not get the right amount of food, and leads to weight loss, dopamine levels decrease.
The results of the research published this year, and of the study conducted in 2008, go some way to providing more information about the physiological and psychological complexities of anorexia, aiding the development of effective anorexia treatment.