Arfid: what is selective eating disorder and what role does genetics play in its development?

It is estimated that between 1 and 5% of the world’s population suffers from an eating disorder that few people know exists.

Known as Avoidant Restrictive Eating Disorder (also known as Binge Eating Disorder or Binge Eating Syndrome or arfidan for its abbreviation in English), the condition is a extreme form of restrictive diet which, if not controlled, can seriously affect a person’s life and health.

As serious as this disorder is, we still know very little about its causes, making it difficult to develop effective treatments.

But in the first twin study of Arfid, our team has now found that it is genetic factors they play an important role in its development.

This research brings us one step closer to understanding what causes artphid and hopefully one day we will find better ways to treat the condition.

Arfid was first defined as an eating disorder in in 2013. People with this condition eat a very limited variety of food or very small amounts of food (or both).

But compared to people with other eating disorders, such as anorexia nervosa, this food restriction it is not driven by body dissatisfaction or a desire to lose weight.

Instead, people may restrict the foods they eat because of sensory aversion to certain tastes, smells and textures, lack of appetiteas well as traumatic experiences while eating, such as choking on food and fear of gastrointestinal pain.

This restriction is so extreme that it leads to weight loss, vitamin and mineral deficienciesand can affect a person’s daily life.

Arfid affects both men and women, while other eating disorders, such as anorexia nervosa and bulimia nervosa, occur more often in girls and women.

Also, unlike other eating disorders, arfid usually develops in infancy.

twins and genetics

We know that other eating disorders are influenced by a person’s genetics (from moderate to high). It is therefore very likely that genetic factors may also partially explain why some people develop artphid and others do not.

We wanted to find out to what extent this was the case, so we looked at something called heritability, a complex concept that measures the proportion of differences in people’s traits that are explained by differences in their genes.

We can use the twin method to estimate the heritability of any trait. This takes advantage of the fact that identical twins share all their genes, while non-identical twins share an average of 50% of the genes that distinguish people from one another.

Furthermore, because twins grow up in the same environment at exactly the same time, we can rule out the possibility that the influences of that shared environment are causing differences between them (as can happen with normal siblings of different ages).

We then compare the similarity of a particular characteristic between identical twins with the similarity between non-identical twins. The degree to which identical twins are more alike gives us an estimate of the heritability of this trait.

To assess the heritability of arfid, we started by looking at data from the Swedish Twin Registry, which tracked the health of just under 34,000 twins. First, we combined data from parent questionnaires and recorded clinical diagnoses to identify children with aphids.

We then apply the twin method and find that Larfid heredity is 70-85%. This means that between 70 and 85% of children had artfid or not, explained by differences in their genes.

This places the arfid in between most hereditary mental disorders. In comparison, the heritability of autism is estimated at 79-84%, and ADHD (attention deficit hyperactivity disorder) at 76-89%.

Furthermore, the heritability of arfid is higher than that of anorexia nervosa (48-74%), bulimia nervosa (55-61%) and binge eating disorder (39-57%), suggesting that it may be a disorder. most heirloom foods.

He hopes for a cure

Findings like these can help reduce stigma and guilt about mental disorders such as artfid and other eating disorders. A person does not decide to develop arphid, and neither does a parent force their child to develop it.

However, the fact that the heritability of arfid is less than 100% also shows that it is not just genes that make someone prone to developing the disorder.

Other factors, such as excessive choking on food or severe allergic reactions, can trigger the development of this eating disorder.

Our findings also suggest that genetic studies have enormous potential to help us understand the causes of arphids. This is what our next research will try to do.

Treatments for arfid are currently being developed using cognitive behavioral therapy and family therapy. However, these methods tend to focus on the symptoms rather than the underlying causes of the eating disorder.

We also don’t know how well these treatments work. But a better understanding of the causes of binge eating disorder, including its underlying biology, will help us develop better treatments.