Authors of a study published in the Journal of Studies on Alcohol and Drugs state that rates of alcohol dependence are elevated in women with eating disorders who engage in binge eating or compensatory behaviours compared with women with eating disorders who do not report binge eating or compensatory behaviours and with healthy controls. Alcohol dependence, binge eating, and compensatory behaviours are heritable; however, it is unclear whether a shared genetic liability contributes to the observable association among these traits, and little information exists regarding this shared liability in men.
Researchers investigated genetic and environmental correlations among alcohol dependence, binge eating, and compensatory behaviours in male and female twins.
Participants included 5,993 same- and opposite-sex twins from the Australian Twin Registry who were assessed for lifetime alcohol dependence and binge eating. Compensatory behaviours were assessed via a general health questionnaire in women only. Biometrical twin models estimated genetic and environmental influences on alcohol dependence, binge eating, and compensatory behaviours.
In women, the multivariate twin model suggested that additive genetic and nonshared environmental effects influenced alcohol dependence, binge eating, and compensatory behaviours, with heritability estimates ranging from 38% to 53%. The best-fitting sex-limitation model was a common effects model that equated all genetic and nonshared environmental influences in men and women. The heritability estimates were 50% and 38% for alcohol dependence and binge eating, respectively. Overall, there were significant genetic correlations between alcohol dependence and binge eating, alcohol dependence and compensatory behaviours, and binge eating and compensatory behaviours.
These findings indicate that common genetic factors may underlie the vulnerability to alcohol dependence and the liability to binge eating and compensatory behaviours.
Source: A Twin Study of Alcohol Dependence, Binge Eating, and Compensatory Behaviours, Melissa A. Munn-Chernoff, AE Duncan, JD Grant, TD Wade, A Agrawal, KK Bucholz, PA F Madden, NG Martin, AC Heath. J. Stud. Alcohol Drugs, 74, 664–673, 2013 [Open access].