It may be difficult for many to understand how and why people with anorexia nervosa starve themselves.  A natural response to someone who is malnourished and underweight might be “just eat more!” But eating for someone with anorexia is far more difficult and distressing than you may think – and neuroscience research is helping us understand why. Complex imaging studies are giving us an increasingly sophisticated understanding of the brain activity that leads individuals with anorexia nervosa to experience intense anxiety before, during and after mealtimes.  

In order to better understand the experience of anorexia, scientists at the University of Colorado Anschutz Medical Campus focused in on the reward-response system in individuals with anorexia and released a compelling new study.  Using brain scans, researchers studied 56 female adolescents with anorexia and 52 healthy adolescents, honing in specifically on brain response to the taste of sugar. Researchers found that brain activity in response to sugar was higher for individuals with anorexia than for those in the control group. Further, the neurological response to sugar was such that instead of triggering a typical reward response (as in “yum, this is good, I want more”), the taste of sugar triggered anxiety.  So this study captured a specific neurological mechanism that is disrupted in anorexia and therefore, leads to eating-related anxiety and consequent food avoidance.

For most people, restricted eating and the associated weight loss leads to certain biological adaptations or changes that trigger heightened interest in food and increased reward response to eating palatable foods. In other words, after a period of deprivation, food just seems more interesting and tastier than ever.  This heightened reward response is a result of complex changes in the body’s production of neurotransmitters – with dopamine, the “feel good” neurotransmitter, at the center of it all. It makes sense if you think about survival: as animals, if food is limited and we are at risk of starvation, our bodies respond by increasing our natural drive to eat.  That said, science suggests that for a minority of people (those with vulnerability to AN), there is a disruption in this reward system. For those with this genetic vulnerability, weight loss leads to increased dopamine response to food but without the feel-good effect. The increased dopamine activity triggers anxiety – not pleasure – understandably, resulting in more intense food avoidance.

These brain imaging studies and others suggest that those individuals with a genetic vulnerability to developing anorexia may be sensitive to food restriction.  So before weight loss sets in, the individual may have a normal response to food but under the influence of weight loss, the reward system adapts – or maladapts, I should say – and food becomes aversive rather than appealing.  For some, these reward system adaptations may even occur before weight loss; it’s hypothesized that these adaptations may occur spontaneously as the hormonal system changes and develops during adolescence.

The increased brain response identified in this study is now being considered a biomarker of the disease. With a greater knowledge of the biological markers that suggest a vulnerability to the disease, researchers may develop more specific treatment interventions and manipulate pathways earlier on.  Further, we find that understanding the way the anorexic brain works, can be incredibly helpful to loved ones, allowing for much more empathy and understanding… including the understanding that someone with anorexia would “just eat” if they could.

How We Help

My3square virtual meal support uses specific interventions to reduce the association between mealtime and anxiety.  We hone in on strategies for coping with the inevitable anxiety that gets triggered by eating.  Learn more about our services, available to recovery-oriented individuals anywhere in the US.

 

In Anorexia, Brain’s Reward Response to Taste Tied to High Anxiety. (2018, July 27). Retrieved from https://psychcentral.com/news/2018/07/27/in-anorexia-brains-reward-response-to-taste-tied-to-high-anxiety/137331.html

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