Anorexia is partly genetic and the risk of developing an eating disorder could be passed onto children, a new study shows.
An international collaboration of scientists found that many people who suffer from anorexia nervosa have mutated DNA on a particular chromosome.
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.
However scientists had noticed that anorexia often ran in families.
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 people without eating disorders.
In more than half of 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.
Professor 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 per cent of all sufferers die as a result of their condition.
Sufferers are aged eight to 80, boys and girls, women and men and over the last 25 years, the number of sufferers has rocketed.
Although the researchers are yet to pinpoint the exact genes involved, they say it puts them beyond the 'needle in a haystack' stage. Once identified, they hope to develop drugs which could prevent the effects.
The study was conducted by the Psychiatric Genetics Consortium Eating Disorders Working Group - an international collaboration of researchers at multiple institutions worldwide.
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, 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.
Anyone affected by the issues in this article can call Samaritans 24 hour helpline 116 123, or Bodywhys at 1890200444 or email firstname.lastname@example.org
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Up to a staggering 200,000 people in Ireland are affected by eating disorders. To mark Eating Disorder Awareness Week, Áilín Quinlan talks to Harriet Parsons, psychotherapist with BodyWhys, and with clinical psychologist Dr Malie Coyne, a lecturer at NUI Galway to address some of the common myths surrounding the issue.
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