What can Cause an Eating Disorder? The Role of Genetics
Could genetics cause an eating disorder in certain people? There is evidence that genetics do play a role when it comes to the cause of anorexia, bulimia causes and the other eating disorders.
Genetics, however, are not the only factor in determining what causes eating disorders. Family relationships play a role and contribute to the causes of eating disorders. Eating disorders and the media are certainly no small contributing factor. Personality factors like self-esteem play a role ... as do other mental health issues. In general, these psychological, behavioral, emotional and environmental factors play a significant role in the cause of an eating disorder. But genetics may play a role as well.
Research on Genetics and whether Genetic Factors can Cause an Eating Disorder
In the 90s, researchers were looking for a link between anorexia and genetics. In 1999 a group of researchers in London looked at serotonin, a key chemical most well known in terms of depression, but also one that controls appetite and sexual desire. The rationale was if anorexics don't have an appetite, then maybe something is wrong with the serotonin levels in the brain. Serotonin is thought to play a role in the causes of eating disorders.
The researchers, including Dr. David Collier, found "variations" in the serotonin gene in anorexics as opposed to the same gene found in people who don't have an eating disorder. Preliminary conclusions were if a woman had this variation, and environmental factors aligned just right, she would be more likely to develop anorexia nervosa. Researchers were on the path to determining the link between anorexia and genetics.
In 2000, researchers studied anorexic women from around the world. They concluded that people with anorexia also have perfectionist traits (shock! naw, really?). Their connection in terms of human genetics info was that perfectionism could be a genetic trait. If perfectionism is genetic, and people who develop anorexia are perfectionists, then the common factor, perfectionism, could be a genetic link to anorexia.
In 2002, researchers, including Dr. Walter Kaye in Pittsburgh, studied families with a history of anorexia nervosa. They looked at 200 families where there were at least two direct blood related people with anorexia. That means there could be siblings who had anorexia, mother/daughter, grandmother/granddaughter. Out of those 200 families, the researchers collected 650 DNA samples. They performed genetic tests and determined they may have found genes that are related to anorexia on Chromosome 1. In addition, they found other genes on seven additional chromosomes that may also be related to the development of anorexia nervosa. (Their findings were published in the March 2002 edition of the American Journal of Human Genetics.)
Research has continued. In 2002, researchers concluded that in terms of drive-for-thinness and obsessionality, markers on Chromosomes 1 and 2 could indicate a genetic component to developing these common personality traits. What that means is you could be born with a predisposition to want to become thin, and you could be born with a tendency to become obsessive about things. Eventually this could lead to developing an eating disorder. However, just because you have these genetic markers doesn't mean you will develop an eating disorder. Other factors must first come into play; the combination could lead to cause an eating disorder.
Interestingly, researchers have found in research with twins that 52 - 56% of the time, identical twins both suffer from an eating disorder as opposed to a rate of only 5 - 11% in fraternal twins. Identical twins share the exact same genetic makeup. Fraternal twins do not. The fact that more identical twins both suffer from an eating disorder strongly suggests that there is a strong genetic component contributing to the causes of eating disorders.
In Conclusion
Genetics definitely play a role in the cause of an eating disorder. Many of these studies have looked at anorexia and genetics - mainly the cause of anorexia. But there have definitely been studies that included looking at genetics and bulimia causes, and contributing factors to the other different eating disorders. What you should really take away from all of this is what I have been stressing here and elsewhere on these pages - what you will read over and over again no matter where you read about eating disorders - there is no single cause of eating disorders. There are numerous factors that interplay and come together in precisely the right way and end up in an eating disorder. And just because the same factors are present in another person's life, doesn't necessarily mean they are doomed to develop an eating disorder. So while there is no single cause of an eating disorder, genetics do seem to be a factor in the overall equation.
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