ANOREXIC pigs have led scientists in Wales to believe that the condition could have genetic as well as psycho-social causes.
John Owen, professor of agriculture at the University of Wales, Bangor, has found intriguing parallels between anorexia in humans and eating disorders in pigs. The parallels suggest that eating disorders could be caused by a recessive gene.
Professor Owen said: "Over the past few years the food industry has seen a preference among consumers for lean meat. In order to meet this demand, farmers and breeders have been breeding leaner animals. Since this trend has begun pig breeders have recognised two named conditions where symptoms similar to anorexia can be found. They are wasting pig syndrome, found in younger pigs, and thin sow syndrome. In both conditions the pigs restrict their normal intake of food.
Two recessive genes, one inherited from each parent, provide a recessive effect. With intensive selective breeding, an increasing proportion of defective genes are inherited. The result is that more animals exhibit the symptoms. It is suggested that this gene sensitises the animals to stressful conditions which then bring about the eating disorder. Stress-inducing situations for pigs would include early separation from the sow and having to mix with pigs from outside their own group, which leads to bullying until a new social order is established."
Professor Owen has worked with Janet Treasure, of the Eating Disorders Research Group at the Institute of Psychiatry, on the research. He believes that the genetic connection could be equally relevant to human anorexics and hypothesises that people subject to it have a recessive gene that controls the body's composition and weight.
This hypothesis is supported by studies of twins and families with anorexia which suggests that there is a strong hereditary element in susceptibility to the condition.