Anorexia could be caused in part by a disruption in the normal processing of cholesterol, which may disrupt mood and eating behavior. This is according to the largest DNA-sequencing study of anorexia nervosa. Scientists have now linked the eating disorder to variants in a gene coding for an enzyme that regulates cholesterol metabolism.
A new direction for research
“These findings point in a direction that probably no one would have considered taking before,” explained Nicholas J. Schork, professor at The Scripps Research Institute (TSRI). Up to 1% of women are affected by anorexia. The mortality rate is 10% or more making it a very deadly psychiatric disease. Anorexics will severely restrict eating, eventually becoming emaciated all the while seeing themselves as fat. Their personalities tend to become perfectionistic, anxious and/or depressed, as well as obsessive. It affects more girls than boys by a 10:1 ratio. While there seems to be a social factor influencing the outcome, studies among twins show there is a genetic component. There is no clear understanding as to how the illness develops.
What are the genetic factors?
Researchers suspect many genes may contribute to the disposition for the disorder. Only a large study would be able to capture the data needed to identify specific genes. Schork worked with an international team of collaborators representing more than 24 research institutions. They used information from more than 1200 anorexic patients and nearly 2000 non-anorexic control subjects. Researchers eventually identified the gene EPHX2, an enzyme known to regulate cholesterol metabolism. “We thought that with further studies this EPHX2 finding might go away, or appear less compelling, but we just kept finding evidence to suggest that it plays a role in anorexia,” exclaimed Schork.
Finding the enzyme is a good start
It isn’t clear how it triggers anorexia or if it maintains the disease. People with anorexia often have high cholesterol levels despite being malnourished. Other studies have shown that weight loss during depression also seem to come with an increase in cholesterol. Studies also show ties between elevated mood and high cholesterol. It may be that anorexics actually feel good when they are not eating. Many of these early hypotheses will be studied further.
Source: MedicalNewsToday, TSRI
