A disease with many faces

Because nothing was known for certain, doubtful or totally inaccurate explanations of eating disorders have also flourished at various times. It has often been difficult to separate the core of the disease from what Cynthia Bulik calls its cultural packaging.

ONE OF THE EARLIEST descriptions of eating disorders concerns the 14th-century nun Catherine of Siena. She fasted for a long time for religious reasons. The people around her were impressed by her seemingly limitless devotion. But a concerned clergy urged her to begin eating again. She reportedly told them that she was ill and could not. Her condition was called anorexia mirabilis, or miraculous self-starvation. But she most likely suffered from what today is called anorexia nervosa and she died of starvation at he age of 33 on 29 April 1380.

In the 1970s the answers were sought in accordance with the spirit of the times in the family environment. Researchers noted that the relationships around individuals with an eating disorder not seldom are characterised by conflict and stress and concluded that a dysfunctional family environment was the root cause of the problem. But many did not recognise themselves at all. Others bought the explanation, leading to guilt and conflicts.

“The notion that it is the family’s fault has caused great damage. Many parents have felt guilty quite unnecessarily. What was not understood earlier was that the disease has a very great impact on the whole family,” says Ata Ghaderi, Professor of Psychology at the Department of Clinical Neuroscience. Today, researchers think exactly the opposite and see the family as part of the solution rather than the problem. In the treatment of young people with eating disorders, the family is involved as an important resource.

“Recent research has also shown that families in which someone suffers from eating disorders are not so special after all. Similar tensions are seen in families where a child suffering from other chronic diseases such as type 1 diabetes,” he says.

TODAY THE PENDULUM has swung from simplistic social models to a combination of psychological and biological risk factors, along with triggering environmental factors. As with many other diseases, most scientists had given up the idea of a simple explanation. Piece by piece, the researchers instead put together a puzzle of many factors that help trigger and maintain the disease. Few or none of the pieces can be found at all with eating disorders, but there is a common overall pattern. Many sufferers are preoccupied with thoughts of their body, food and weight. It is also common to have other psychiatric problems such as depression, anxiety and obsessions. But the sufferers can often feel that there is something else, or at least something more than their thoughts and feelings, that makes it impossible to eat normally.

“Psychological factors are part of the clinical picture. But they alone cannot explain why someone begins to starve him- or herself as with anorexia nervosa; there are stronger physiological mechanisms that are brought into play,” Ata Ghaderi goes on.

The strongest risk factor for eating disorders is slimming. Many people who try to lose weight give up after a while and revert to their usual eating habits. But some react instead with a period of increased eating compared with before they began slimming. This could in turn trigger the person to resume their slimming. If the cycle continues, the person risks getting stuck in a pattern of swings between dieting and overeating. Over time this can turn into binge eating, which is a combination of overeating and a feeling of loss of control over their eating.

A small percentage see their dieting as an unexpectedly positive experience. Instead of irritation and inconvenience, they discover that the negative energy balance, hunger, brings about a sense of calm or even euphoria. Instead of lack of energy, they feel a sense of activation that some channel through physical exercise, which gives them an even greater negative energy balance. Such a person runs the risk of developing anorexia nervosa.

“Dieting is common but few people develop anorexia nervosa. It is also common to eat despite feeling full but only in a few people does this turn into binge eating and a sense of loss of control. We therefore need to learn more about the factors that determine whether an individual develops an eating disorder or not,” says Cynthia Bulik.

WE HAVE KNOWN for a long time that eating disorders are more common in some families and studies of twins carried out by Cynthia Bulik and other researchers show that 40-60 per cent of the risk of developing anorexia nervosa can be explained by genetic factors.

The genetic components do not mean that someone is destined to suffer from the disease; environmental factors are at least as important. “It’s important to study both the biological and the environmental aspects of eating disorders and how they interact,” Cynthia Bulik says.

Which genes are involved has been completely unknown until now. Together with international colleagues, Cynthia Bulik recently conducted a study of abnormalities associated with the disease.

When they analysed the results, the researchers were able for the first time to link the disease to a specific region in our genes. The area is situated on chromosome 12 and has previously been linked to type 1 diabetes and autoimmune diseases. The researchers also saw that gene variants that increase the risk of anorexia nervosa are linked to the neuroticism personality trait and to obsessions. This is consistent with previous research, which found that neuroticism, anxiety and obsessions are more common in people with eating disorders.

Such relationships can be interpreted in several ways. It is for example possible that anxiety contributes to the occurrence of eating disorders, is a result of eating disorders, or co-exists with an eating disorder. According to Cynthia Bulik there is reason to believe that anxiety can be a contributing factor, at least in young people.

“We have in previous studies linked anxiety in children and young people to a greater risk of developing eating disorders later in life,” she says.

The results also showed that gene variants that were previously linked to a high level of education are also inked to anorexia nervosa. In Cynthia Bulik’s opinion, this confirms previous observations that eating disorders are more common in homes with a high level of education. But this can now be understood in a new light.

“One of the myths about eating disorders is that they are due to young individuals pushing themselves too hard, because they have seen their parents do the same. What we have now discovered is that gene variants that have been linked to a high level of education also increase the risk of developing anorexia nervosa. This means that the relationship to the family's ambitions may be on the genetic level and perhaps is not at all a question of environmental influence within the family,” Cynthia Bulik says.

THE MOST REMARKABLE result according to Cynthia Bulik was that genetic factors associated with anorexia nervosa were also negatively correlated to overweight and obesity. More specifically, gene variants that increase the risk of anorexia nervosa are also linked to a favourable composition of blood fats, but also to a low BMI, low likelihood of obesity, and low percentage of fat in the body’s composition.

“Throughout my career, people have asked me if anorexia nervosa is the opposite of obesity, and I have always answered no. But these results make me fairly confident that I’ve been wrong,” she says.

ACCORDING TO ATA GHADERI, not just anyone can suffer from anorexia nervosa since a specific genetic vulnerability is needed. He believes, however, that anyone, or at least many more, can suffer from bulimia nervosa, or binge eating disorder.

“It's largely about the fact that the brain’s attention has become overly preoccupied with food. We know that the same thing happens in people who diet; when you diet, you start to think very much about calories and food,” he says.

In a similar way, people with eating disorders focus strongly on the body, and sometimes a divergent body image compared to the people around them. In an ongoing project Ata Ghaderi is trying to learn more about what this may be due to.

In an experiment, subjects were asked to look at their own hand and estimate its size. They were asked to make a new estimate after having been instructed to focus on the details of their hand’s appearance. They also estimated the size of other objects before and after the focus on details and the sequences were randomised. It turned out that they estimate their hands to be larger after they focus on the details.

“Constantly focusing on the body and measuring and weighing can probably contribute to it being perceived as larger,” says Ata Ghaderi.

In parallel with the increased focus on food and body, the person devotes a great deal of energy to inhibiting their behaviour, to avoid eating foods that are constantly present in their thoughts. Things break down for some periodically and the person eats compulsively. Ata Ghaderi calls this the “What-the-hell effect”.

“When you eat something that you regard as useless and wrong, it feels like crossing a boundary and relinquishing control, which also makes you tired over time, so they ignore it all and eat large amounts,” he says.

NOT ALL RESEARCHERS agree on exactly how the psychological factors relate to one’s eating behaviour and how to best break the circle. Most treatment options combine eating training and weight goals with variants of psychological treatment, with the aim of giving the person their own psychological tools to break the circle, and avoid landing in it again.

“The aim is for the patient to be their own detective and themselves understand the function of their behaviour. What am I doing, and what do I get out of it? Perhaps I binge-eat to calm myself down? If the person comes to that insight, it may be possible to replace the binge eating with something else that has the same function without being harmful,” Ata Ghaderi goes on.