A claim popularized by feminists is that anorexia (and other eating disorders) are caused by unhealthy media images of thin women. In the past decade this claim has been undermined by cross-cultural studies of societies with very different ideal female body images, but a recent Dutch survey is the first to provide any evidence that anorexia may have a genetic as well as psychological component.
American researchers began by studying mice who experience an eating disorder similar to anorexia. Research determined that the mice were deficient in a protein called agouti, which was involved in the formation of skin pigment. The substance had a second use, however — its presence in the brain was necessary to stimulate the mice to eat. Those mice who produced too little of this protein suffered from an anorexia-like eating disorder.
Dutch researchers then turned to human beings. Taking blood samples from 145 patients diagnosed with anorexia, the researchers found that 16 of the patients had genetic mutations of the gene that produces the agouti protein in human beings.
This follows up on earlier research that found high risks of anorexia in people whose relatives also suffered from the disorder. According to the BBC, studies of twins have shown that when one twin suffers from anorexia, the other twin has an extremely high 50 percent risk of suffering from anorexia as well. Having a family member who suffers from anorexia increases the risks of suffering from the disorder from 1 in 200 to 1 in 30.
Rather than being simplistically caused by images of thin females in the media, anorexia is turning out to be a very complex disorder with a number of likely factors contributing to its development.
Source:
Anorexia ‘has genetic basis’. Marlene Smits, The BBC, October 7, 2001.