Anorexia is partly genetic, and the risk of developing an eating disorder could be passed on to children, a study shows.
Many people who suffer from anorexia nervosa have mutated DNA on a particular chromosome, an international collaboration of scientists found.
Until recently, the condition was thought to be driven by a mix of physical, social and environmental triggers such as anxiety, depression or Western culture’s obsession with thin models.
The researchers from King’s College London and the University of North Carolina compared the genetic code of 3 400 people with anorexia to see how it differed from that of people without eating disorders.
In more than half of the anorexia cases, they found faulty genes which are linked to neuroticism, schizophrenia and metabolism — adding to evidence that the condition is a mental and metabolic condition.
Prof Cynthia Bulik, of the University of North Carolina, said: “Anorexia nervosa was significantly genetically correlated with neuroticism and schizophrenia, supporting the idea that anorexia is indeed a psychiatric illness.
“Unexpectedly, we also found strong genetic correlations with various metabolic features including body composition (BMI) and insulin-glucose metabolism.
“This finding encourages us to look more deeply at how metabolic factors increase the risk for anorexia nervosa.”
More than 1.6 million people in the UK are affected by eating disorders.
There are more deaths from eating disorders than from any other mental illness, and it is estimated that 10% of all sufferers die as a result of their condition.
Both women and men can suffer, and numbers have rocketed over the past 25 years.
Once researchers have identified the genes involved, they hope to develop drugs to prevent the effects.
The study was conducted by the Psychiatric Genetics Consortium Eating Disorders Working Group, an international collaboration of researchers.
Dr Gerome Breen, of King’s College London, said: “In the era of team science, we brought over 220 scientists and clinicians together to achieve this large sample size.
“Without this collaboration, we would never have been able to discover that anorexia has both psychiatric and metabolic roots.”
The researchers are continuing to increase sample sizes and see this as the beginning of genomic discovery in anorexia nervosa.
Dr Laramie Duncan, of the University of Stanford, California, added: “Working with large data sets allows us to make discoveries that would never be possible in smaller studies.”
The study was published in The American Journal of Psychiatry. © Telegraph Media Group Limited