A Swedish study has concluded that as many as 30 per cent of women with the binge-eating disorder bulimia nervosa could be suffering from an imbalance of sex hormones.

The PhD thesis is the work of Dr. Sabine Naessén of the Department of Woman and Child Health at the Karolinska Institutet, Sweden's largest medical training and research centre.

Dr. Naessén suggests that some women with the compulsive over-eating disorder may have too much testosterone, the male sex hormone. "We have shown that one third of female bulimics have metabolic disorders that may explain the occurrence of the eating disorder. These disorders may in certain cases express the hormonal constitution of the patient, rather than any mental illness", she says.

The study shows that bulimia has hormonal and genetic components, as well as the psychological element. The hormone imbalance is due to an over-abundance of testosterone and an insufficiency of the female sex hormone, oestrogen, an active ingredient in oral contraceptives.

It is thought that too much testosterone causes a person to feel very hungry and crave high-calorie foods rich in sugar and fat.

21 bulimic women were treated with oestrogen-dominated oral contraceptives. Within 3 months half of them reported feeling less hungry, and having decreased craving for fatty and sugary foods. And 3 of the women were said to be completely cured with this treatment.

Dr. Naessén suggests "this is a very strong effect. Hormone treatment may very well be an alternative to cognitive behavioural treatment."

Bulimia is usually defined as a psychological disorder normally treated with psychotherapy, with cognitive behavioural therapy being the one most commonly recommended.

According to the diagnostician's "bible", the DSM-IV-TR® Diagnostic and Statistical Manual of Mental Disorders published by the American Psychiatric Association, for patients to be diagnosed with bulimia (as separate from anorexia nervosa), they must be showing the following 4 symptoms:
- Binge-eating "recurrently", i.e. eating far more than most people normally do, together with a feeling that they can't stop or control their eating.
- Repeatedly and inappropriately compensating for the over-eating, such as over-medicating with laxatives, fasting, exercising to exhaustion, or making themselves vomit.
- Been doing these two things (binge-eating and inappropriately compensating) repeatedly at least twice a week for the last 3 months.
- Overly judging themselves in terms of the weight and shape of their bodies.

Unfortunately bulimia is very hard to spot, because unlike other eating disorders, such as anorexia, the bulimic will appear to be of normal height and weight, and because of the shame and guilt associated with the condition, have learned how to mask their symptoms. The long term effect is one of malnutrition, and it may well be a symptom related to this that first brings the bulimic to the attention of the doctor.

Click here for the Eating Disorders Association

Written by: Catharine Paddock
Writer: Medical News Today