A landmark international genetic study published in Nature Mental Health reveals that eating disorders are influenced by psychiatric and metabolic biology rather than primarily psychological factors. Researchers analyzed DNA from tens of thousands of individuals worldwide, including participants from New Zealand, uncovering distinct genetic variations tied to binge eating and anorexia nervosa.
A collaborative effort led by King’s College London and the University of North Carolina, featuring input from the University of Otago, challenges the view that these are primarily psychological illnesses. By mapping the human genome across global datasets, scientists have provided some of the clearest evidence yet that DNA plays a role in these conditions.
In Plain English: The Clinical Takeaway
- Genetics Over Stereotypes: DNA analysis shows that biological markers influence eating disorders, suggesting they are not primarily psychological.
- Divergent Pathways: Anorexia nervosa and binge eating operate on distinct genetic tracks, reacting differently to metabolic factors like body mass index (BMI).
- Targeted Treatments on the Horizon: Understanding the specific molecular loci (fixed positions on a chromosome) associated with each disorder may help develop more precise treatments targeting the specific biology of each condition.
Uncovering the Genomic Architecture of Binge Eating and Anorexia Nervosa
The research, executed under the umbrella of the Eating Disorders Working Group of the Psychiatric Genomics Consortium and partially funded by the US National Institute for Health (NIH), includes the largest ever genetic study of anorexia nervosa. Scientists compared the DNA of about 25,000 individuals with anorexia nervosa and almost 40,000 individuals with binge eating against over 1.2 million unaffected people across 27 global datasets.
According to Dr. Helena Davies, postdoctoral research fellow at the Institute of Psychiatry, Psychology & Neuroscience (IoPPN) at King’s College London and joint-first author on the study, the findings confirm on a genetic level that eating disorders are not just about body weight. A significant portion of the gene variants tied to these conditions differ from those associated with an individual’s weight. The team identified six loci associated with binge eating and eight loci associated with anorexia nervosa in people from European backgrounds. Six of the anorexia loci had been implicated in a 2019 genetic study, while two were identified for the first time.
Lead senior author Dr. Jonathan Coleman, Senior Lecturer in Statistical Genetics at King’s IoPPN, stressed how crucial it is to look past anorexia nervosa to grasp the genetics behind binge eating—a behavioral sign that manifests across multiple eating disorders, prominently in binge-eating disorder, alongside bulimia nervosa and select instances of anorexia nervosa. The data also highlighted metabolic intersections, noting that a binge-eating locus near a well-known gene called FTO—tied to higher body weight—suggests that binge eating may help explain part of the connection between FTO and higher BMI.
Divergent Metabolic Relationships and Regional Research Impact
The genomic relationship between body weight and eating disorders differs depending on the condition. Researchers observed that genetic factors associated with higher body weight were associated with an increased likelihood of binge eating. Conversely, for anorexia nervosa, genetic factors associated with higher body weight appeared to reduce the likelihood of developing the disorder. Crucially, these genetic contributions could not simply be explained by genes influencing body weight or body mass index.
| Condition | Genomic Loci Identified | Relationship with Higher Body Weight / BMI Genetics | Primary Source Cohort Scale |
|---|---|---|---|
| Binge Eating | 6 loci | Associated with an increased likelihood of the symptom | ~40,000 cases / 1.2M+ controls |
| Anorexia Nervosa | 8 loci (2 newly discovered) | Associated with a reduced likelihood of the disorder | ~25,000 cases / 1.2M+ controls |
University of Otago Associate Professor Jenny Jordan noted that these results help understand both shared and distinct causes of eating-related traits, which may help develop more precise treatments targeting the specific biology of each condition. The next phase of the research will draw on approximately 4,000 New Zealand participants.
Contraindications & When to Consult a Doctor
The Future of Precision Psychiatry in Eating Disorders
Subsequent stages of the investigation intend to broaden the scope of analyses to incorporate additional eating conditions, including Avoidant/Restrictive Food Intake Disorder (ARFID) and atypical manifestations, alongside diverse global ancestries, with the goal of enhancing the applicability of the outcomes across varied populations.
References
- Nature Mental Health: Genomic analysis of binge eating and anorexia nervosa
- Psychiatric Genomics Consortium: Eating Disorders Working Group Meta-Analyses
- National Institutes of Health (NIH): Research Portfolio on Genetic Contributions to Psychiatric Conditions
Disclaimer: This article is for informational purposes only and does not substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your physician or other qualified health provider with any questions regarding a medical condition.
