When patients look at their family medical histories, the first thing they probably look for is diabetes, cancer or heart disease. It’s true that those health issues can show up in family histories, but they’re not the only things that you can be looking for. Eating disorders can be linked genetically just like heart disease and cancer, so make sure you’re keeping an eye out for eating disorders like anorexia and bulimia if you’re looking up your family’s medical history.
Though research has found that 40-50% of the risk of having an eating disorder is linked to genetics, few people realize that this is a factor in both anorexia nervosa and bulimia. In fact, anorexia has been found to be just as inheritable as disorders like bipolar disorder and schizophrenia.
Family studies have shown that women with a mother or sibling that have faced an eating disorder are 12 times more likely to develop an eating disorder themselves. Even more startling are the results that have been gained from studying twins and eating disorders. If one of a pair of identical twins suffers from anorexia, there is a 59% chance that the other twin will also develop the disorder. In fraternal twins, who share only 50% of their genetic makeup, the likelihood of developing an eating disorder drops to 11%, but the data is still very significant. These hereditary studies show that genetics can play a huge role in the likelihood of developing an eating disorder.
Though there are many ideas and hypotheses surrounding genetics and eating disorders, a study from London and Pittsburg showed that serotonin receptors might play a role, whereas other studies suggest that personality traits passed down from one generation to the next might be what triggers the development of an eating disorder. And though there’s significant evidence that shows this genetic predisposition, it’s important to state that not everyone who has a family history anorexia or bulimia will develop an eating disorder—not all triggers are genetic. Non-biological triggers such as trauma, outside pressures and problematic diets can be the catalyst for eating disorders as much as genetics.