Anorexia nervosa is a psychiatric disorders characterized by an overwhelming fear of gaining weight coupled with extremely low body weight and distorted body image. Over the years, research has suggested a range of potential causes, including personality traits, genetics, and developmental challenges. However, emerging research has suggested that anorexia may be a metabolic disorder.
Anorexic woman. Image Credit: Westend61 / Shutterstock
What is Anorexia?
Anorexia nervosa (AN) is a type of eating disorder which is considered to have the highest mortality rate of any psychological disorder. Those with AN may over evaluate their weight and overall shape, and as a result, engage in behaviors to reduce their body weight. Such behaviors include over-exercising, purging coupled with self-induced vomiting, and the misuse of diuretics or laxatives. Overall, the disorder is characterized by an individual having a distorted body image, extremely low body weight, and an overwhelming fear of putting on weight. Further signs and symptoms of AN include:
- Lying about your weight
- Lying about when and what food you have consumed
- Avoiding eating foods considered to be fattening
- Skipping meals or eating little food during meal times
What Causes Anorexia?
Like many psychological disorders, research has not highlighted one sole cause of anorexia. Instead, many researchers believe the onset is dependent on a range of factors such as conflicts within their family, having a biological predisposition, developmental challenges and transitions. However, emerging research investigating the biological causes of anorexia suggests that AN may, in fact, be a metabolic disorder.
Is Anorexia a Metabolic Disorder?
A genome-wide association research project involving over 100 academic staff from across the globe have worked to discover eight main genetic variants that are associated with AN. A meta-analysis was conducted and featured the data of over 16,000 and 55,000 cases of AN and control group data, respectively, from 17 different countries.
The group of researchers attached several thousand markers on genomes allowing for comparisons to be made between each participant. This enabled the researchers to ultimately pinpoint specific locations of differences within the genomes. Overall the team found eight areas within the genome which they deemed to be associated with the onset of AN.
Following this, the results were compared to those gathered from similar genetic studies investigating the biological causes of a range of other psychological conditions. It was found that the genetic basis of AN overlapped with those seen in schizophrenia, depression, anxiety, and obsessive-compulsive disorder. This could explain some of the comorbidity and similarity between the symptoms seen in those with AN and previously mentioned psychiatric conditions.
In addition to this, the research also found a link between AN and physical activity. Specifically, it was suggested that there might be a genetic motivation behind the high levels of physical activity often seen in those with the eating disorder.
Relating to the health profile of those with AN; it was found that the genetic factors of AN were also associated with lipid, metabolic, and anthropometric traits which were independent of factors which affect body mass index.
Dr. Cynthia Bulik Discusses Anorexia Nervosa Genetics Study (short version)
What is the Impact of this Research?
This research has been significant in identifying new plausible causes of AN. Traditionally, it was thought that any metabolic implications seen in those with AN were caused as a result of having the eating disorder. However, this research questions the direction of the association between metabolic disruptions and AN. Thus, metabolic differences may be a contributing factor to the development of the psychiatric condition.
Furthermore, conclusions from this research may be able to help shape treatment methods better. For example, the study’s researchers recommended that the condition should be considered to be a ‘metabo-psychiatric disorder’. This also places a need for medical professionals to consider both the metabolic and psychological factors when formulating new treatment methods.