L’anorexia nervosa is the deadliest of all psychiatric illnesses. 5 to 15% of people suffering from it would die prematurely (undernourishment, heart problems, suicide, etc.). And for good reason, it would affect between 1 and 4% of women and about 0.3% of men. Patients may have low body weight and a distorted view of how their body looks. They are thus terrified of the idea of gaining weight. As a result, some eat little, while others exercise hard to burn more calories than they consume.
A new study, published in Nature Genetics this Monday, July 15, allows scientists to take a step further in understanding this disease. Researchers from the University of North Carolina at Chapel Hill (USA) and King’s College London (UK) have indeed discovered that this eating disorder is not only a psychiatric condition, but is also linked to metabolism problems.
Metabolism genes involved
The researchers compared the DNA of nearly 17,000 people with anorexia and more than 55,000 healthy controls, of European ancestry and from 17 different countries. They finally identified eight genes linking the pathology to anxiety, depression and obsessive-compulsive disorder, as they expected. But they also found links to genes involved in fat burning, physical activity and resistance to type 2 diabetes.
In fact, metabolic genes – even healthy ones – seem to combine with those linked to psychiatric problems and increase the risk of anorexia, scientists have found. Half of the cases could thus be explained by genetics, and the rest attributed to life events and other factors.
Environment and genetics interact
Scientists have long considered the family environment and perfectionism to be factors responsible for the disease. But according to Gerome Breen, geneticist at King’s College London and director of this new research, it would be the opposite: “It’s not perfectionism that causes anorexia, it’s the tendency to have anorexia that causes the increase in perfectionismhe explains to Guardian. We believe that family environment and genetics interact”.
“What our study meanshe continues, it’s that we can no longer treat anorexia – and perhaps other eating disorders – as purely psychiatric or psychological disorders.” Moreover, the few genes identified would explain only a fraction of the pathology. It is likely that hundreds, if not thousands, actually contribute to the risk of developing it. Researchers will now study the metabolism of people suffering from anorexia, in order to develop therapies.
Read also :
- Testimonial: “I came out of the hell of bulimia-anorexia”
- Social networks encourage extreme thinness
