Geschatte leestijd: 2 minutenResearchers believe they have found the neurological cause why people with anorexia and bulimia can ignore their hunger.
Anorexia and Hunger
Last month we already paid attention to eating disorders such as anorexia following the documentary “Emma Wants to Live”. The most basic response to people with anorexia is the question:
“Why don’t you eat?”
A simple question that science struggles with. Researchers from the University of Colorado now think they can offer more insight into what goes on in the head of someone with anorexia or bulimia. Literally.
They published their findings in Translational Psychiatry and describe how normal patterns of appetite are actually reversed in people with the mentioned eating disorders. Normally, it’s the hypothalamus that regulates appetite and makes you want to eat. In people with an eating disorder, it appears that other areas in the brain can disrupt this function and even reverse it.
This study provides evidence that white matter structural as well as effective connectivity within the energy-homeostasis and food reward-regulating circuitry is fundamentally different in anorexia and bulimia nervosa compared with that in controls.
Dr. G. Frank, University of Colorado
Dr. Guido Frank specializes in eating disorders. He wanted to study the hierarchies in the brain related to hunger and appetite. What causes hunger and what causes you to listen to it or not? His team used scans to compare the brains of 26 healthy women with those of 26 women with anorexia or bulimia. They wanted to see how these brains responded to tasting a sugar solution.
Significant Differences in Brain Structures
They found significant differences in the brain centers that regulate the reward system for taste and appetite. These were mainly found in the white matter of the brain, which facilitates communication between different areas of the brain. The role of the hypothalamus also differed between the two groups.
In healthy women, the hypothalamus directed areas that stimulate appetite. However, in women with an eating disorder, this connection was much weaker, and the information even went in the opposite direction. The researchers suspect that this allows the brain to ignore the signals to eat.
Below you can see this schematically depicted. Above are the left and right halves of the brains of the control group, below are both halves of the brains of women with an eating disorder (AN: Anorexia, BN: Bulimia). Even without a background in neurology, you can see that certain things work very differently in the group with an eating disorder. For example, you can see that the connection between the hypothalamus and the ventral striatum (“VS”) is almost absent or reversed in the group with an eating disorder.
A Bit More Understanding
Neurology is not my forte either. So I’ll spare you the exact texts from the study, for both your enjoyment and mine. The most important news here, however, is that there is more insight into the functioning of the brains of people with an eating disorder. More insight can lead to better treatment methods. But even if this insight doesn’t yet lead to better treatment, it can at least lead to more understanding.
After all, when you know that the brains of people with an eating disorder simply work differently, you and your friends and family might be able to show more understanding.
References
- G K W Frank, M E Shott, J Riederer, T L Pryor. Altered structural and effective connectivity in anorexia and bulimia nervosa in circuits that regulate energy and reward homeostasis. Translational Psychiatry, 2016; 6 (11): e932 DOI: 10.1038/tp.2016.199
