Researchers have long explored the idea that a person’s likelihood of developing an eating disorder — specifically anorexia nervosa and bulimia — has a genetic component. According to a new study conducted by scientists from the University of Iowa and the University of Texas Southwestern Medical Center, heredity plays a more important role than we ever knew.
The team studied families in which eating disorders spanned generations and uncovered a revealing link: Two rare genetic mutations — in the ESRRA and HDAC4 genes — increase a person’s risk of developing anorexia or bulimia by 90 percent and 85 percent, respectively, according to U.S. News & World Report. Although the mutations are powerful, they’re also rare — 1 in 1,000 have the ESRRA mutation and 1 in 10,000 have the HDAC4 mutation.
“In this study, we had two large families with multiple members affected by eating disorders. We found that a different gene was mutated in each family (ESRRA in the first family and HDAC4 in the second),” Michael Lutter, MD, an assistant professor of psychiatry at the University of Iowa and the senior author of the study, told Yahoo Style.
“This was an unbiased study (that means we looked at all 20,000 genes in the body instead of taking educated guesses at which genes might be mutated). Out of all 20,000 genes in the body, we find two proteins are mutated and they just happened to bind each other and do very similar things in the body. That was surprising to me and really let us feel like we were on the right path, because the chance of that happening by random luck is pretty small.”
The two genes in question were found in a pathway of the brain that boosts a person’s desire for food, according to the publication. The mutations inhibit that function, though, squashing a person’s appetite. Lutter told U.S. News & World Report that this research will allow scientists to better understand how to boost that pathway to prevent eating disorders in people who are prone to developing them.
In the U.S., 20 million women and 10 million men experience a clinically significant eating disorder at some time in their life, according to the National Eating Disorders Association (NEDA). This new research lends even more credence to the argument that eating disorders are bona fide psychiatric conditions, as NEDA confirms.
“One very common misconception is that eating disorders are not ‘real’ diseases, and that people with eating disorders are just seeking attention,” Lutter told Yahoo Style. “We were hoping that by identifying some of the mutations that increase the risk of developing an eating disorder, we would be able to understand the neurobiology of eating disorders better, with the hope of reducing social stigma, improving health care coverage, and identifying novel treatments.”
Leslie Sim, a clinical child psychologist at the Mayo Clinic, tells U.S. News & World Report, “We’re really starting to see this as a true biological illness, where essentially we’re seeing these kids sharing these temperament predispositions that likely places them at risk.” These temperament predispositions include “a high level of anxiety, a strong desire to avoid harm and danger, a fear of making mistakes, and a drive for perfection.” She says these types of kids prefer to maintain control in their lives; they prefer predictability and structure.
Past studies have pointed to genetics as a precursor to eating disorders. The American Psychological Association published evidence in 2002 of a genetic linkage to anorexia on chromosome 1, and called anorexia a “complex psychiatric disorder.” Researchers said at the time, “This is the first genetic linkage finding we have in anorexia, so we’re quite excited.” Research published by the U.S. National Library of Medicine in 2004 identified “strong support for familial transmission” of eating disorders, though scientists admitted the theory was in its infancy.
This most recent study by the University of Iowa and the University of Texas Southwestern Medical Center takes findings to a new level, though. “Our study is slightly different than other past genetic studies because of our approach,” Lutter told Yahoo Style + Beauty. “Most other studies look for common mutations that give a very small increase in risk of developing an eating disorder. Our study looked for rare mutations that give a very high chance of getting an eating disorder.
“The most similar comparison would be the so-called breast cancer genes (BRCA1 and BRCA2). Most women with breast cancer don’t have mutations in BRCA1 or BRCA2, but a very high percentage of women with mutations in BRCA1 or BRCA2 get breast cancer,” he added. “Because the effect is so large, it taught researchers a great deal about how the disease develops. Our findings are somewhat similar in that people with the ESRRA or HDAC4 mutations have a very high risk of developing an eating disorder.”
Genetics don’t make up the whole story though. According to the authors of the study, the tendency to develop anorexia or bulimia is very much a nature vs. nurture situation. Environmental factors play a significant role. “This really can set the stage for utilizing food and controlling weight and shape, because it adds a whole other layer of simplicity to their life. It’s a road map for more certainty,” Sim told U.S. News & World Report.
“In reality, the research pretty clearly shows that the risk of getting an eating disorder is largely genetic (maybe up to 50-70 percent of the risk is inherited),” Lutter told Yahoo Style + Beauty. He points to the “Western ideal of thinness and beauty” as an environmental factor, while Sim posits that “the prevalence of dieting” can bring on an eating disorder. “It’s been said that genes provide the kindling, and dieting provides the fuel,” Sim told the publication. “People who might be vulnerable, who might have those genes, may never develop an eating disorder if they never go on a diet.”
If you are suffering from an eating disorder or suspect someone you love is, know that help is available, and that there are many documented stories of recovery. Help and support is readily available by contacting the National Easting Disorders Association, which can help you find a treatment facility in your area that caters to your unique needs.
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