Genetic Influence of Eating Disorders

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Until recently eating disorders were believed to originate from influences of developmental, social, and biological factors. Now, in the world of mental health, researchers are beginning to understand that there is also a genetic influence on eating disorders.

Studies We Do Know About

Family studies are typically used to identify if a disorder is found among related members. Research has shown that there is a seven to twelve increase in the prevalence of anorexia and bulimia in relatives of those who have an eating disorder [1].

Even with this data, it is challenging to determine if the disorders are genetic or environmentally influenced.

Other studies have shown that symptoms of eating disorders, such as purging, restricting or fasting, and binge eating are about 46-72% genetic. Results have also shown that self-image and body-image throughs are also somewhat genetic [1].

Genetic Studies

There have been some studies that look at the association of chromosomes to eating disorder pathology. Researchers have been able to identify serotonin and dopamine-related genes in these studies and an increase in the 1438/A allele of the 5-HT2A receptor in women with anorexia nervosa [1].

They have not yet been studied in those with bulimia nervosa.
Further research has also looked at the genes that are related to characteristics and thought patterns in those with anorexia and bulimia.

Michigan State University has recently found that there are genetic based risk factors that contribute to eating disorders. Kelly Klump, an associate professor of psychology at MSU reported that the origin of eating disorders has biological beginnings [2].

She goes on to say that during puberty there is an increased risk for an eating disorder to develop, almost 50% can be attributed to genetic factors that start with the puberty process.

Klump assessed over 500 14-year old female twins and found that prior to puberty environmental factors were the sole reason for the development of eating disorders. But as puberty begins to start, the genetic risk is ‘activated’ and contributes to the development of eating disorders [2].

A gene can be defined as “a sequence of DNA containing the code to make a protein. Very few characteristics or disease are the direct results of a single or even several such proteins” [3].

Eating disorders are incredibly complex and involve various reasons for etiology: biological, environmental, behavioral, family influences, peer interactions, and much more. Genes do have an impact on an eating disorder but are not the sole cause for the emergence of one.

This leads to the idea of susceptibility genes that influence eating disorders. This can increase the risk of the development as it starts due to certain triggers.

UNC School of Medicine reports identifying the very first genetic location for anorexia nervosa, and suggest that there are metabolic underpinnings to anorexia as well [4]. This study looked at almost 3,500 individuals with anorexia, and nearly 11,000 people without an eating disorder.

Researchers discovered one genome, chromosome 12, that they contribute to the development of anorexia. This region, on Chromosome 12 has also been shown to be associated with Type 1 diabetes and autoimmune disorders.

Within this area, researchers also discovered that anorexia is genetically connected to other mental health disorders like neuroticism and schizophrenia. This suggesting that anorexia is, as already thought, a psychiatric illness [4].

The study also revealed high genetic correlations between body mass composition (think BMI) and insulin-glucose metabolism.

Single Gene Causation or Multiple?

Dr. Kaye and Dr. McCurdy conducted a study of over 2000 individuals both with and without eating disorders. They found that there is more than one gene that creates an eating disorder.

Moreover, it also supports the idea that those who do develop anorexia and bulimia tend to have distinct temperaments and personality traits. These characteristics tend to emerge in childhood, before an eating disorder starting [5].

In binge eating, a genome study was conducted to see if there is a genetic factor influencing binge eating [6]. Researchers were able to identify a gene, CYFIP2, that was downregulated in the development of myelination, or the process of forming a sheath around a nerve fiber to allow nerve impulses to move more rapidly.

The Boston University School of Medicine were able to identify cytoplasmic FMR-1 interacting protein 2 (or the CYFIP2). In this study, they also suggest that myelination, when decreased, maybe a neuropathological consequence of binge eating [6].

Final Thoughts

Overall, the idea that genes can determine eating disorder symptoms, behaviors, thought processes, and onset is a fascinating one. As we have a deeper understanding and furthering of science within the mental health field, unknown causation may be identified.

Teen girl on bicycleAs we move towards continued research in this area, it is important to remember that there are many areas which contribute to the development of eating disorders. Environmental factors, social relationships, and media, family influences, as well as biological factors all play a role in when and how an eating disorder develops in one single individual.

We do know that eating disorders can present differently in each person, but there is typically a core of cognitive and behavioral patterns that link each sufferer together. Regardless of the influences that contribute to an eating disorder, we understand that recovery is reachable for all who seek it.


Image of Libby Lyons and familyAbout the Author: Libby Lyons is a Licensed Clinical Social Worker and Certified Eating Disorder Specialist (CEDS). Libby has been practicing in the field of eating disorders, addictions, depression, anxiety and other comorbid issues in various agencies. Libby has previously worked as a contractor for the United States Air Force Domestic Violence Program, Saint Louis University Student Health and Counseling, Saint Louis Behavioral Medicine Institute Eating Disorders Program, and has been in Private Practice.

Libby currently works as a counselor at Fontbonne University and is a Adjunct Professor at Saint Louis University, and is a contributing author for Addiction Hope and Eating Disorder Hope. Libby lives in the St. Louis area with her husband and two daughters. She enjoys spending time with her family, running, and watching movies.


References:

[1] Berrettini, W. (2004, November). The Genetics of Eating Disorders. Retrieved September 06, 2017, from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3010958/
[2] Genetic Factors for Eating Disorders Discovered. (n.d.). Retrieved September 06, 2017, from https://www.sciencedaily.com/releases/2007/05/070511150158.htm
[3] Reflections on Genes and Eating Disorders. (n.d.). Retrieved September 06, 2017, from http://nedic.ca/reflections-genes-and-eating-disorders
[4] U. (2017, March 12). For anorexia nervosa, researchers implicate genetic locus on chromosome 12. Retrieved September 06, 2017, from https://www.sciencedaily.com/releases/2017/05/170512081332.htm
[5] Genetic Studies. (n.d.). Retrieved September 06, 2017, from http://eatingdisorders.ucsd.edu/research/genetic-studies.html
[6] Boston University Medical Center. (n.d.). Genetic risk factor for binge eating discovered. Retrieved September 06, 2017, from https://www.sciencedaily.com/releases/2016/10/161026170543.htm


The opinions and views of our guest contributors are shared to provide a broad perspective of eating disorders. These are not necessarily the views of Eating Disorder Hope, but an effort to offer discussion of various issues by different concerned individuals.

We at Eating Disorder Hope understand that eating disorders result from a combination of environmental and genetic factors. If you or a loved one are suffering from an eating disorder, please know that there is hope for you, and seek immediate professional help.

Published on October 17, 2017.
Reviewed By: Jacquelyn Ekern, MS, LPC on October 17, 2017.
Published on EatingDisorderHope.com