Are People Genetically Predisposed for Eating Disorders?
Article Contributed by Jacquelyn Ekern, MS, LPC & Crystal Karges, MS, RDN, IBCLC
Understanding the many factors that comprise our body image is a complex issue. While many may believe that the mass media is largely to blame for the making of poor body image, research is finding that a genetic component may be involved.
The media can be a culprit for generating images that falsify the reality of human bodies, but what drives an individual to idealize the representation of body perfection? As scientists unfold the blueprint of our genetic make-up, it is evident that both environment and genetics play an integral role in the formation of body image.
Investigating the Interplay Between Genetic and Environmental Factors
A research study published in the International Journal of Eating Disorders studied the possible genetic influences on thin-ideal internalization. While earlier research has analyzed the effect of psychosocial influences, such as media exposure, on body image, this particular study sought to investigate the possible interplay between genetic and non-shared environmental factors in the thin-ideal internalization .
The team of researchers from Michigan State University carried out their study by interviewing over 300 female twins between the ages of 12 and 22. The “thin-ideal internalization” was evaluated among participants by rating how much they desired to look like people seen in the mass media. Interestingly, researchers found that the scores on thin-ideal internalization were much more similar among identical twins than those of the fraternal twins.
The Findings Show A Genetic Link to Eating Disorders
Based on these findings, scientists were able to determine that genetic factors are indeed a part of body image issues, since it is known that identical twins share 100 percent of their genes and fraternal twins share approximately 50 percent of their genetic makeup .
Based on their findings from this study, researchers were able to approximate that the heritability of thin idealization could be estimated at about 43 percent . It was also observed that shared environmental factors, such as exposure to the same media, did not have as great as impact as expected.
The Details of the Discovery
In response to this discovery, authors noted,
“Interestingly, the heritability estimate of more than 40 percent is remarkably similar to the heritability of disordered eating and eating disorders and suggests that thin-ideal internalization is just as heritable as the outcomes it predicts.”
The authors of this study also hypothesized that the genetic factors that sway the internalization of a thin ideal may have common ground with heritable factors that affect personality characteristics, such as perfectionism.
Further Research Is Needed
While further research is needed in this area, the findings of this study give credence to the notion of genetic influence on body image. As a society and culture as a whole, we are continually saturated with unrealistic images of beauty ideals. However, the impact of media is greater on some individuals than others, catalyzing a response that can directly influence our body image. As research has demonstrated, this can be largely attributed to genetic factors.
The Magnitude of Genetics for Eating Disorders
Understanding the magnitude of what interplays in the formation of body image is crucial to breaking stigmas that often surround eating disorders. Our genetic blueprint is a fundamental part of our development, a steering force that can predispose us to a variety of issues, including our perceived body image or risk of an eating disorder.
Knowing that there is more to the story than simply a “desire to be thin” gives deeper compassion to the individual who may be suffering with poor body image or an eating disorder, as well as give greater incentive for the advancement of treatment measures.
: Suisman et al. “Genetic and Environmental Influences on Thin-Ideal Internalization.” International Journal of Eating Disorders published online 3 October 2012.