A mother and her young daughter are enjoying themselves at an outdoor cafe. – Bilanol // Shutterstock
Are eating disorders inherited? Let’s look at the data.
Contrary to common beliefs, eating disorders are not a matter of choice; they are serious conditions that can be life-threatening. While social and environmental factors do play a role in the development of eating disorders, extensive research over the years has shown that genetics, particularly family history, significantly increase the risk of these conditions.
Pioneering studies from the late 1990s and early 2000s have revealed that anorexia nervosa and bulimia nervosa, two of the most prevalent eating disorders, have a strong familial connection. For example, a comprehensive study of nearly 2,000 individuals found that anorexia was uncommon in families without eating disorders, but female relatives of those with eating disorders were over 11 times more likely to develop anorexia themselves. Similarly, female relatives of individuals with bulimia had about four times the risk of developing the disorder, as concluded by the study.
Recent research has corroborated these earlier findings, indicating a significant genetic component in eating disorders. A twin study conducted in Sweden in 2006 estimated that genetics contribute to 56% of the risk for anorexia nervosa, while environmental factors have a lesser impact, according to the study.
However, a notable gap in research has been highlighted: Many studies have mainly focused on white, slim, young women. Experts stress that these oversights influence who receives treatment and who may be overlooked, resulting in underdiagnosis and undertreatment among men, individuals of color, older adults, and those with larger body sizes. The exclusion of diverse populations only perpetuates stereotypes about at-risk groups, prompting a call for more inclusive studies to gain a comprehensive understanding of eating disorders.
To delve deeper into the biological aspect of eating disorders, Charlie Health has reviewed existing research on genetics and family history as risk factors for these conditions.
Genetics can elevate the risk for both anorexia and bulimia. Twin studies have demonstrated shared genetic factors between anorexia nervosa and bulimia nervosa, indicating that having one disorder increases the likelihood of developing the other due to these shared genetic underpinnings.
A study from 2019 concluded that both anorexia and bulimia have comparable heritability, with genetic factors accounting for approximately 43% of the risk for anorexia and 41% for bulimia. This implies that over 40% of the risk of developing either disorder is attributed to genetic factors inherited within families. Additionally, the study found a substantial genetic overlap between the two disorders, with a genetic correlation of 0.66, signifying a strong connection, according to researchers.
Binge eating disorder has also been shown to be “moderately heritable.” There has been less research on the heritability of binge eating disorder compared to anorexia or bulim
Genetics play a significant role in the development of eating disorders, with up to 43% of the variation attributed to genetic factors, a recent study reveals. Avoidant Restrictive Food Intake Disorder (ARFID) is considered to be highly heritable, with genetics accounting for about 79% of the risk, according to the same study. Researchers point out that this genetic influence is comparable to that seen in other eating disorders and neurodevelopmental disorders.
Recent genetic research, utilizing advanced sequencing techniques and global data sharing, has started to illuminate the genetic underpinnings of eating disorders, particularly anorexia. Studies have identified multiple genetic regions associated with the risk of anorexia, with common genetic variants explaining up to 17% of the heritability of the disorder. Certain genes linked to lower body mass index (BMI) may directly increase the likelihood of developing anorexia, the study suggests.
Notably, researchers have discovered a strong genetic link between anorexia, obsessive-compulsive disorder, and metabolic traits, indicating that both psychological and biological factors play a role in the disorder.
Despite these findings, the genetic risks of severe eating disorders are still not fully understood. Individuals with severe and long-standing anorexia nervosa, characterized by at least 7 years of illness, a lack of response to treatment, extremely low BMI, and a significant impact on quality of life, are often excluded from genetic studies. This omission may hinder progress in identifying genetic risk factors and developing more effective treatments for those with the most severe forms of the disorder.
This information was provided by Charlie Health and reviewed and distributed by Stacker.
