The Triple Helix @ UChicago

Winter 2018

"The Science and Sociology of Eating Disorders" by Rose Cytryn

 

The Harvard Chan School of Public Health called upon the Center for Disease Control (CDC) to officially monitor eating disorders as part of their national disease surveillance.  The National Notifiable Disease Surveillance System (NNDSS) is a part of the CDC that works to monitor and track diseases at the local, state, and federal levels. The Strategic Training Initiative for the Prevention of Eating Disorders, a coalition initiated in 2009 from a joint effort between the Harvard Chan School of Public Health and Boston Children’s Hospital, started with the goal of training and generating skill sets to combat eating disorders. Their public call on the CDC to officially recognize and surveil anorexia nervosa, bulimia nervosa, and binge eating disorder demonstrates an increasingly serious perspective being taken in regard to eating disorders. The NNDSS adds conditions to the list as environmental issues or new pathogens or viruses emerge as potential issues. These collections and data serve to help track trends of diseases, their possible increase or decrease in prevalence, and the specific areas and demographics that are most greatly affected. 

The National Eating Disorder Association (NEDA), defines an eating disorder as a “…serious but treatable mental illness…” [2]. There is no certain source or cause for eating disorders, however leading ideas in the field suggest that it is in fact a combination of environmental, biological, and psychological factors. Because there is no specific cause, and until now, no specific and intense tracking of disorders, there is not a defined checklist of symptoms. Patients with varying relationships toward food, their own body image, and a myriad other behavioral and physical symptoms can indicate an eating disorder.

Often, when speaking about eating disorders, one is speaking of anorexia nervosa (AN), which is characterized by intense weight loss, difficulty in managing weight and restrictions on caloric intake, or bulimia nervosa (BN), identified by cycles of binging and self-induced vomiting, and binge eating disorder, indicated by recurring episodes of binge eating. The difficulty in truly understanding the causes of these disorders is that, though they affect 20 million women and 10 million men at some point in their lives, these disorders manifest very differently in everyone [3]. Because of this, studies occurring now are looking to psychological and physical factors to understand the potential root causes of eating disorders rather than just biological factors.

According to Dr. Anke Hinney, and Dr. Anna-Lena Volckmar out of the University of Duisburg-Essen, the symptoms and sources of eating disorders are both psychological and physical. Drs. Hinney and Volckmar are looking at the differences between the origins of anorexia nervosa and bulimia nervosa in twins and in families to determine their possible heritability. They found that heritability for anorexia nervosa estimated between 44% and 88% and heritability for bulimia nervosa estimated between 28% and 83% [4]. The study noted that individual environmental factors were not estimated, though they play a major role, allowing the remaining liability. In a second study, conducted by Dr. Hinney and Dr. Volckmar, it was found that “first degree female relatives of patients with anorexia nervosa or bulimia nervosa have at least a tenfold increased risk of developing the full syndrome of AN themselves compared with an epidemiological sample. For BN the risk was approximately fourfold…” [4].

The study continued to explore the presence of serotonin in the biological makeup of a girl beginning puberty and the implications that the neurotransmitter has on body weight, body image, and eating behaviors and disorders. The study found elevated levels of 5-hydroxyindolacetic acid in “weight-restored patients with AN or BN…” [4]. 5-hydroxyindolacetic acid is a metabolite of serotonin and is used, through urine examinations, to determine bodily levels of serotonin. 

Dr. Sarah Leibowiz from the Rockefeller University in New York has studied not only the presence of serotonin as it relates to eating disorders, but the inhibitory nature of serotonin on eating and feeding behavior. The evidence suggests that serotonin affects the “circadian patterns of feeding and macronutrient choice through satiety mechanisms involved in the termination of feeding behavior” [5]. When stimulated with serotonin, the paraventricular and ventromedial nuclei and the suprachiasmatic nucleus reduce carbohydrate intake through the termination of feeding.5 It is believed that the connection between serotonin function and the circadian rhythm trigger is an inhibition and lack of desire to eat due to deficits in energy.   

While eating disorders are clearly based in physiological and psychological foundations, the overlap between the neurobiology of eating disorders and the popularized and romanticized portrayal of, typically female, characters suffering from these disorders makes for a world in which eating disorders are often viewed as vain, superficial, and merely products of the patients desire to look better. The emphasis on the femininity and the culture of idealizing portrayed body types emphasizes the influence of the media and the entertainment industry on a typical patient diagnosed with an eating disorder. 

In data collected by NEDA, of all girls in elementary school who read magazines, 69% say that the pictures they see influence their idea of the “ideal body shape,” while 47% say these pictures cause them to want to lose weight. Furthermore, NEDA reported that one in every 3.8 commercials portrays a message about what is considered attractive, and the average American teenager sees 5,260 of these commercials over the course of a year [6].

The intensity and consistency with which people, specifically teenage girls, are bombarded with these messages serve to normalize these disorders, shifting their impression from disorders to means to reach certain expected ends. 95% of people with eating disorders are between 12 and 25 years of age but only 10% of them will ever seek help [7]. Leading studies show that individuals with untreated anorexia have a mortality rate 18 times higher than their non-anorexic peers [8].

Calling upon the CDC to conduct more strict and regulated surveillance of these diseases is about more than just the reported trends that will be found. And while research is speeding ahead in understanding the specific ways in which serotonin may be decreasing the desire to eat, it is also important to call attention to eating disorders in hopes of growing the percentage of people who seek help. In an environment in which neurobiological disorders are written off as drama and vanity, each percentage counts. 

References

[1] “What Are Eating Disorders?” National Eating Disorders Association. February 21, 2018. Accessed February 29, 2018.  https://www.nationaleatingdisorders.org/what-are-eating-disorders

[2] "Our Work." National Eating Disorders Association. February 22, 2018. Accessed February 24, 2018. https://www.nationaleatingdisorders.org/about-us/our-work.

[3] Hinney, Anke, and Anna-Lena Volckmar. “Genetics of Eating Disorders.” Current Psychiatry Reports , 8 Nov. 2013, doi: 10.1007/s11920-013-0423-y.

[4] Leibowitz, Sarah F. “The Role of Serotonin in Eating Disorders.” Drugs, vol. 39, no. Supplement 3, 1990, pp. 33–48., doi:10.2165/00003495-199000393-00005.

[5] “Home.” And Eating Disorders, www.mirror-mirror.org/media-influence-on-body-image.htm.

[6] McTheny, Christina. "Am I Pretty Now." The Odyssey Online. August 27, 2017. Accessed February 24, 2018. www.theodysseyonline.com/am-pretty-now.

[7] Steinhausen, Hans-Christoph. "Outcome of Eating Disorders." Child and Adolescent Psychiatric Clinics of North America18, no. 1 (November 17, 2008): 225-42. Accessed February 24, 2018.

 

 
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