I no longer support genetics research into eating disorders. Okay, that’s not quite right: I no longer support genetics research into eating disorders under the pretense that it will improve treatment outcomes or prevent eating disorders. I just don’t believe it. Moreover, I think emphasizing the need for a genetic understanding of eating disorders shifts focus away from research and, more importantly, from actions, that can yield much greater benefits much quicker.
It wasn’t always like this. In my third (junior) year of university, I wrote a mini-review on the genetic and neurobiological etiology (cause) of anorexia nervosa. In it, I argued that “in order to improve recovery outcomes, more specific treatments based on genetic and neurobiological evidence need to be developed.” I concluded by writing,
However, with the advent of large-scale genetic databases and worldwide collaboration among researchers resulting in larger sample sizes, the future of AN research
… Continue reading →
Genetics play an important role in the development of eating disorders and disordered eating behaviours. To date, many (over 30!) twin studies have been done and all but two found significant genetic effects on the development of eating disorders and disordered eating. However, no methodology is without limitations and tentative conclusions become more convincing when the findings are confirmed using different experimental approaches.
Twin studies, while they offer many advantages, are not that good when it comes to detecting shared environmental effects on a particular trait (literally, evens that happen to both twins and affect them in the same way). Fortunately, twin studies are just one of several different ways that researchers can use to study heritability. (A quick reminder: Heritability measures the amount of the variability in an observable trait/behaviour that can be attributed to genetic variation. This is NOT the same as … Continue reading →
Puberty at an early age increases the risk for disordered eating behaviours such as bingeing and purging (Jacobi et al., 2004; Kaltiala-Heino et al., 2001). What’s more, the hormone estradiol moderates the risk of disordered eating behaviours. More precisely, in a group of twins with low estradiol levels, differences in disordered eating are likely due to environmental factors (such as family, school, friends), but in a group of twins with high estradiol levels, the differences in disordered eating are more likely due to genetic factors. (I blogged about it here.)
Essentially, estradiol partially moderates the extent to which genes affect disordered eating.
This is interesting because the estrogen system has a role in regulating body weight and food intake, influences eating behaviours during the menstrual cycle, and obviously plays an important role during puberty. Moreover, one study showed that estrogen receptor genes (proteins that bind estrogen) are … Continue reading →