Eating disorders: New insight into what causes them

Two new studies show that family may play a complex part in eating disorders

Eating disorders have been with us for centuries. Lord Byron was undoubtedly anorexic, as was Elizabeth Barrett Browning. Identifying the origins of the illness is complicated. There seems to be interplay between family history, culture and social pressures as well as biological and psychological causes. Two new studies appear to bear this out.

Recently a team of Dutch and German scientists led by Roger Adan at the University of Utrecht in Holland, identified a genetic mutation that appears more frequently in some people with anorexia than in those without.

The mutation arises in a gene sequence for a protein that is involved in controlling appetite and body weight. The scientists suspect that those with the variant form of the gene may find it easier to lose weight than those without, because their appetite is suppressed.

The study compared 145 anorexia patients with a control group of 244. It found the genetic mutation in 11 per cent of people with the disorder, compared to 4.5 per cent of the controls. From this finding, the scientists inferred that having the mutation could double your risk of developing anorexia.

It is possible that effective drug treatment for some anorexia patients could be developed from this research. ‘It’s clear that there is a genetic component contributing to susceptibility in anorexia nervosa,’ Roger Adan told the New Scientist, while conceding that it only explains a small number of anorexia cases.

Steve Bloomfield of the Eating Disorders Association (EDA) agrees that the mutation can only affect a small proportion of anorexia sufferers. ‘This is an interesting development, but it still doesn’t apply to around 90 %,’ he says. Bloomfield emphasises that any news about these mysterious illnesses contributes to a greater understanding of how they develop.

Psychology is a key component in eating disorders, and a study carried out by Dr Anne Hahn-Smith, from the University of New Mexico in America, suggests there’s a psychological link between mothers’ and daughters’ self-esteem. Young girls who have high levels of ‘maternal identification’ – in other words they want to be like their mothers - had higher self-esteem, a more positive body image and fewer eating problems than women who didn’t want to emulate mum.

The study, published in the International Journal of Eating Disorders, was based on interviews with 92 mothers and their eight-to-13-year-old daughters. ‘Many theories have
supported the idea that mothers were to blame for daughters’ eating disorders and body image problems, and we wanted to see if this was true,’ she says.