Introduction
The standard theory regarding the causes of the eating disorders anorexia nervosa and bulimia nervosa is social effects. However, recent research points to a significant hereditary component of these diseases. The contribution of genetics can be understood in major psychiatric (mental disorders) disorders. Eating disorders refer to abnormal eating patterns, behavior, and disturbances in attitudes and perceptions toward weight and shape. Anorexia nervosa (AN) and bulimia nervosa (BN) are common eating disorders. Anorexia nervosa (AN), bulimia nervosa (BN), and binge-eating disorder (BED) run in families and are heritable. The heritability of diseases and disorders had to be estimated indirectly through family or twin studies. This article shows the link between genetic factors and eating disorders.
What Are Eating Disorders?
Eating disorders are a group of serious mental health conditions characterized by an unhealthy preoccupation with food, body weight, and shape. They typically involve extreme emotions, attitudes, and behaviors surrounding food and eating, which can have negative physical and psychological consequences.
The following are the types of eating disorders:
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Anorexia Nervosa (AN) - AN refers to an extreme fear of weight gain despite being thin or weak.
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Bulimia Nervosa (BN) - BN is characterized by alternating patterns of uncontrollably eating large amounts of food. It emerges after a period of dieting.
How Are Genetics Related to Eating Disorders?
Developmental, social, and biological processes are causes of eating disorders. Cultural and behavioral attitudes towards society are supposed to be the cause of eating disorders. Mental and emotional disturbances are responsible for these behaviors. Dieting behavior is quite common in eating disorders. Only fewer populations are affected after this. Recent studies show that biological vulnerability might be genetic. However, genes can not act alone in causing eating disorders. The following eating disorders are linked to genetics:
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Anorexia Nervosa (AN) - AN is familial. The consistent diagnostic flux seen in eating disorders and specific presentations does not breed true in families. Twin studies have yielded heritability estimates for AN ranging from 0.28 to 0.74. The differences in diagnosis between AN and BN are partially accounted for by shared genetic factors, with twin-based genetic correlations ranging between 0.46 and 0.79. The twin studies of AN showed common comorbidities that reflect shared genetic factors with major depression and obsessive-compulsive disorder (OCD) correlating genetic factors. A wider range of findings from the studies revealed notable genetic relationships between AN and other psychiatric conditions, such as schizophrenia (mental disorders), personality factors including neuroticism, and educational attainment. The significant genetic relationships found between AN and metabolic (the cycle of the process which is essential for life process) traits (features of individuals). These relationships included positive genetic relationships with high-density lipoprotein cholesterol and negative genetic relationships with body mass index (BMI), obesity, fasting insulin, and fasting glucose. Overall, our results supported rethinking AN as a mental and metabolic disorder.
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Bulimia Nervosa (BN) - Due to fewer resources, researchers are less familiar with the genetic distribution of BN than AN. People with family members diagnosed with BN are at a higher risk of developing eating disorders in general and BN in particular. BN's heritability is thought to be around 0.60. There is a substantial genetic correlation between AN and BN (0.46-0.79), as well as between bulimic behaviors and alcohol abuse (0.33-0.61). Although there is a strong genetic link between AN and BN, there may also be some specificity because co-twins of people with bulimic symptoms are more likely to develop BN than AN. The researchers are using genetic variations linked to BN by actively collecting genetic samples from people with BN. This endeavor will aid in the understanding of genes and others that are specific to BN.
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Binge-Eating Disorder - BED is heritable and also accumulates in families. Since BED has just recently been recognized as an official diagnostic category, there are not many genetic studies published on this disease. Twin study estimates heritability based on twins range from 0.39 to 0.45. There are strong genetic links between binge eating and alcoholism, as well as between binge eating and bulimia symptoms (overeating, vomiting, etc.). In addition, there is a weak genetic correlation (0.34) between obesity and BED. The researchers are actively seeking BED patients to investigate BED-related biochemical pathways.
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Other Eating Disorders - Numerous research involving families and twins have not yet been conducted on eating disorders. Large samples are required to determine the exact cause of eating disorders. One strategy might be getting information from large health maintenance organizations with computerized databases or nations with health registers.
How Can This Knowledge Be Used to Help Patients With Eating Disorders?
Clinically, those who suffer from eating disorders and their loved ones and families are very interested in genetic studies. The need for genetic counseling for people with psychiatric disorders and their families has been enforced. Even in the absence of genetic testing, genetic counseling should be made to help people make meaning of genetic information from their family history can lead to important outcomes, including improved knowledge, a more accurate understanding of risk, and increased empowerment and self-efficacy.
Conclusion
Genetic research in eating disorders is accelerating rapidly, and new findings for AN, BN, and BED are expected to emerge in the coming years. Concerted efforts must also be made to extend genetic research to other eating disorder presentations, such as avoidant and restrictive food intake disorders. Awareness of genetic factors in eating disorders is needed to educate and support patients and families. Clinicians and genetic counselors can both play important roles in this process.
