Anorexia nervosa is seen as serious a psychiatric disease, but the devastating illness may also stem from problems with metabolism, according to a new global study.
Anorexia nervosa is characterised by having dangerously low body weight and a distorted view of how your body looks, as well as being terrified of putting on weight. It affects between 1% and 4% of women and about 0.3% of men.
For the first time, scientists have identified eight genes associated with an increased risk of developing the eating disorder. The findings have been described as groundbreaking.
Researchers analysed the DNA of 16,992 people with anorexia and 55,525 people without the disease from 17 countries.
The study, published in Nature Genetics, found genetic mutations that were more common in anorexia patients, including some that control the body’s metabolism, particularly those involving blood sugar levels and body fat.
“There is something in those systems that has gone awry,” professor Janet Treasure, from the Institute of Psychiatry at King’s College London, told BBC News.
Researchers now say the disease should be considered a disease of the mind and body.
So what does this mean?
While researchers have not fully explored how these mutations work, they suspect the mutations might allow people to starve their bodies for longer as opposed to the majority of people for whom weight loss triggers signals in the body that push back, stimulating appetite to ultimately control a weight ‘set point’ .
“It’s possible that when people lose weight with anorexia nervosa, they haven’t got such strong drivers getting the set-point back to normal, Prof Treasure explained.
How significant are these findings?
The findings are very significant in that they increase understanding of the origins of the illness, suggesting there are a number of aspects from both the body and mind at play.
Nick Martin, head of the QIMR Berghofer genetic epidemiology laboratory, told ABC News researchers had known for quite a longtime there were genetic factors influencing the psychiatric mental and health aspects of anorexia, but did not know what the specific genes were.
However, it was the strong links with metabolism that had taken researchers by surprise, he said, adding it could explain why some patients struggle to maintain a healthy weight, even after undergoing treatment.
Scientists say this could open the door to developing new treatments for the disease down the track.
There is also hope that by knowing they could be genetically predisposed to the disease, patients might be more likely to seek treatment.
If you or anyone you know need help or support for an eating disorder or concerns about body image, please call Butterfly Foundation National Helpline on 1800 334 673 (ED HOPE).