Are Eating Disorders Genetic? A Look At Hereditary Factors
Eating disorders are serious mental disorders that affect many people. While environmental factors and personal experiences may be potential risk factors, a common question people ask is, “Are eating disorders genetic?”
Research suggests that eating disorders may be influenced by genetics. However, researchers are continuing to explore the genetic factors linked to eating disorders, and new findings may lead to advances in how these disorders are diagnosed and treated.
How do genetics play a role in eating disorders?
Researchers have looked into how genetic factors contribute to eating disorders like anorexia nervosa and bulimia nervosa. Family history, specific genes, and interactions between genetic and environmental influences may all influence these disorders.
Are all eating disorders influenced by genetic factors?
Not all eating disorders have been equally studied for their genetic links. Individuals with anorexia nervosa tend to show a strong genetic predisposition to this disorder. Other eating disorders like bulimia nervosa and binge-eating disorder also seem to have genetic factors.
Although the genetic links for other eating disorders are less clear, researchers suggest that genes may still play a role. Environmental factors, such as dieting culture and stress, may interact with genetics to increase the risk of these disorders. The interaction between different factors makes it challenging to pinpoint genetics as a single cause.
Genetic links to anorexia nervosa
Anorexia nervosa is recognized as having a strong genetic influence. Research shows that anorexia nervosa (AN) is highly heritable, with estimates ranging from . Various genetic factors may affect molecular pathways that contribute to AN.
The serotonin or 5-hydroxytryptamine (5-HT) system, which influences food intake, mood, and body weight, appears to be altered in those with anorexia nervosa. Notable potential targets include the 5-HT2A receptor gene and the 5HT-transporter-linked polymorphic region (5-HTTLPR).
Dopamine is a chemical in the brain that influences how we think, feel pleasure, behave emotionally, and eat. Changes in certain genes, like DAT1 and DRD2, which control dopamine levels, have been connected to anorexia nervosa. For example, different forms of the DRD3 gene may make the symptoms of anorexia nervosa worse.
Studies on genes related to opioids show that opioid receptors, which affect how we experience rewards and our appetite, are linked to anorexia nervosa. Specific changes in the OPRD1 gene are especially connected to the restricting type of anorexia nervosa.
Genes that control appetite, such as those related to leptin and ghrelin, may also be linked to anorexia nervosa. For instance, people with anorexia nervosa often have lower levels of leptin, which may affect regulation of energy and food intake. They also tend to have higher levels of ghrelin, a hormone that boosts appetite.
Hereditary patterns in binge eating disorder
Research has shown that binge eating disorder also has a strong genetic link. Twin studies indicate that the heritability of binge eating disorder is between . Therefore, a person who has a close relative with binge eating disorder may be at a higher risk of developing the disorder.
Dopaminergic gene variations may also be involved. Changes in genes like DRD2 and OPRM1 are connected to a higher sensitivity to rewards, which can lead to binge eating. People with certain variations in these genes may find eating more enjoyable, which may increase their likelihood of overeating.
Other genetic factors may include genes that regulate appetite. Hormonal differences, such as lower levels of the PYY hormone, have been found in people with binge eating disorder compared to those with anorexia nervosa. Variations in genes like NR3C1 and CLOCK have also been linked to BED.
Genetic factors contributing to bulimia
Twin and family studies estimate that genetics can account for 28% to 83% of the risk for bulimia nervosa. These studies suggest the strong hereditary links of the disorder.
Research suggests that problems in serotonin pathways may contribute to bulimia nervosa. For instance, the 5-HTTLPR transporter gene affects how serotonin is taken up in the brain and might make some people more vulnerable to developing bulimia nervosa.
Dopaminergic genes may also play a part in bulimia nervosa. Changes in the dopamine system, which influences how we experience rewards and emotions, have been linked to bulimia nervosa. The DAT1 gene, which helps control the reabsorption of dopamine, along with changes in the DRD2 and DRD3 receptors, is believed to be involved in these changes.
Genes that regulate appetite are still being studied, but some of them, like those related to leptin and hormones such as PYY and GLP-1, may influence bulimia nervosa. Patients with bulimia nervosa often have abnormal levels of these hormones. For example, lower levels of PYY, which helps control feelings of fullness, might play a role in the disorder.
Other risk factors of eating disorders
Several factors may contribute to the risk of eating disorders beyond genetics. These include psychological, family, cultural, and biological influences.
Psychological factors
Psychological factors and major psychiatric disorders may play a role in eating disorders. Individuals with obsessive-compulsive disorder (OCD) may develop unhealthy eating habits due to their need for control and perfection. Anxiety disorders may cause people to use food as a way to cope with stress. When someone has a mental health disorder, they might turn to food as a way to cope with stress or emotional pain.
Self-esteem may also affect eating behaviors. People with low self-worth might turn to food for comfort or restrict their intake to feel better about themselves. This negative relationship with food can worsen over time, making it harder to break unhealthy patterns.
Family dynamics
Family dynamics may influence eating behaviors. Certain parenting styles, like being overly controlling about food, may lead to harmful eating patterns. Children might mimic their parents' attitudes toward food and body image. If a parent has an eating disorder, children may be at a higher risk of developing one themselves.
If a child doesn't feel understood or supported, they may turn to food for comfort. Conversely, families that focus on dieting and body image may unintentionally contribute to challenging eating behaviors.
Cultural pressures
Cultural pressures may push individuals toward eating disorders. Society often values thinness, which can make people feel like they need to lose weight to be accepted. Media representations often show mostly slim and fit bodies as ideal, which may worsen eating disorders.
Many individuals may sense a need to change their eating habits to fit in or gain approval online. Social media and cultural expectations may make people think they’re inadequate, leading them to adopt unbalanced eating behaviors to achieve the "perfect" body.
Personality traits
Certain personality traits may influence the development of eating disorders. People with perfectionist tendencies may hold themselves to impossible standards, including in their eating habits. They may feel pressured to maintain a specific weight or body shape.
Impulsivity and compulsivity may also be related to eating disorders. Some individuals may be compelled to binge eat impulsively, while others may compulsively restrict their intake. Both types of behaviors can lead to serious health problems over time.
Biological factors
Biological factors may also play a role. Hormonal imbalances can affect appetite and mood, making it difficult to keep nutritious eating habits. Research suggests that imbalances in neurotransmitters like serotonin and dopamine may influence the risk of an eating disorder.
Some people might genetically have a slower or faster metabolism, influencing their body mass index (BMI) and eating behaviors. These biological differences can make it hard to adopt and maintain beneficial eating habits, especially if they’re compounded by other risk factors.
Recognizing these varied risk factors may support better prevention and treatment strategies.
Finding help for an eating disorder
If you notice signs of extreme dieting, binging, or distorted body image, it may be time to seek support. Physicians and mental health professionals may provide initial assessments. The National Eating Disorders Association offers resources and referrals to specialized treatment centers as well as a helpline for support.
Support groups may also benefit those experiencing an eating disorder. These groups offer a place to discuss experiences and encourage one another. The National Association of Anorexia Nervosa and Associated Disorders provides various support groups and programs.
Hospitals and outpatient clinics may also have specialized programs for eating disorders. Treatment options may include therapy, nutritional counseling, and sometimes medication.
For college students, campus health services may be a starting point. Many universities have counseling centers that provide support and referrals to local treatment options.
Online support for anorexia nervosa, binge eating disorder, or other eating disorders
For individuals who feel hesitant about traditional in-person therapy, online therapy may be a valid option. Online therapy provides the flexibility to receive help in various formats, such as messaging and video calls. Online therapy platforms may also allow you to schedule sessions at a time that works for you, even after business hours.
Is online therapy effective for eating disorders?
One study explored how online cognitive-behavioral therapy (CBT) affected symptoms of eating disorders. CBT aims to help people reframe negative thought processes that may be underlying unwanted behaviors or emotions.
The study developed and tested an online therapy program for people with bulimia nervosa or binge eating disorder. The program was well-received, with 73.2% of participants completing the treatment. Many participants experienced improvements in their eating disorder symptoms, and these positive changes were still evident three months after they finished the program.
Takeaway
What causes an eating disorder?
Genome sequencing and controlled family studies suggest that some people have a genetic vulnerability to developing an eating disorder. But, like many psychiatric conditions, eating disorders are also heavily influenced by psychosocial factors such as personality traits, a culture focused on dieting, and negative messaging from others about one’s weight.
Are eating disorders genetically inherited?
The fields of genetic epidemiology and psychiatric genetics are still exploring the extent to which genetic risk factors influence psychiatric conditions. However, we do know that eating disorders, in particular anorexia nervosa, seem to have at least some genetic basis.
Different chromosomal regions also show significant locuses (or significant associations) with different disorders. Gene sequencing, candidate gene studies and family and twin studies have identified some genetic variations as potential contributors to the development and severity of anorexia nervosa, for example—such as genes that influence reward and weight gain. People with bulimia nervosa or binge eating disorder may experience an increased sensitivity to reward from food due to changes in dopaminergic reuptake
Metabolic genetic correlations revealed by such genome-wide association studies and gene discovery studies suggest that there may be significant biological links between eating disorders and anxiety and affective disorders, like OCD or major depression. Changes in genetic markers for sequences that affect appetite regulation may also play a role, and alterations in serotonergic genes likely affect emotional regulation in ways that promote disordered behavior.
What age do eating disorders start?
Typically, eating disorder symptoms start sometime in adolescence or early adulthood. However, it’s possible for a person of any age to develop an eating disorder.
Can eating disorders like anorexia nervosa or binge eating disorder be cured?
There’s not necessarily a one-and-done cure, but people can fully recover from eating disorders with the right support. “Recovery” is a somewhat nebulous term, but agreed-upon criteria centers primarily around improved physical and psychological well-being, as well as reduction or elimination of problematic eating behaviors. In broadly defined bulimia nervosa, for instance, recovery may mean that the person no longer engages in purging behaviors like self-induced vomiting or excessive exercise.
Recovery may also mean that someone no longer engages in caloric restriction and has been able to maintain a healthy weight or eating pattern for a set period of time.
Often, recovery requires psychological interventions as well, such as learning emotional regulation skills (like taking a few seconds to breath when experiencing food-related anxiety). Factors such as comorbid autoimmune disorders, psychiatric conditions, and other illnesses or psychosocial elements can complicate recovery.
How can you beat an eating disorder?
Eating disorder recovery is typically aided by a team of nurses, specialists, and other health care professionals. There are both inpatient and outpatient options available to manage symptoms and ensure one’s physical safety.
Can children have eating disorders?
While less common, children can develop eating disorders, even those young enough to be in kindergarten. Anorexia nervosa and ARFID (avoidant/restrictive food intake disorder) are more likely to develop at younger ages, as can binge eating disorder. Genetic influences may be more pronounced in these cases.
What type of person develops an eating disorder?
Anyone can develop an eating disorder, but eating disorders tend to arise when certain biological, psychological, and environmental risk factors are present. Personality traits like perfectionism and a social environment that encourages unhealthy food behaviors like excessive restriction are just a couple of such factors.
How many years does it take to overcome an eating disorder?
Eating disorders are typically chronic, meaning symptoms last for months to (more frequently) years. Depending on the disorder, it can take years for someone to even start treatment—according to one study, an average of anywhere from 2.5 to 5.5 years from the onset of symptoms meeting the criteria outlined in the Diagnostic and Statistical Manual of Mental DIsorders.
What personality type is most likely to have an eating disorder?
Personality traits such as perfectionism can come with an increased risk of developing an eating disorder.
What foods trigger eating disorders?
Foods themselves don’t trigger disordered eating behaviors. However, many people with eating disorders find that they have “safe” foods and “unsafe” foods. In anorexia nervosa, “safe” foods may be heavily restricted to low-calorie foods like raw vegetables. In bulimia and binge eating disorder, “unsafe” foods may be those likely to trigger a binge—often calorically dense foods like pizza and sweets.
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