Approved research

Genes, Education, and Gene-Education Interactions in Obesity and Mental Health

Lay summary

Tackling obesity and depression is vital for population health, because of their high prevalence and societal costs. One policy advocated to reduce obesity and depression is increasing educational attainment, as it is viewed as a fundamental cause of health disparities. As obesity and depression also have strong genetic bases, it is possible that education additionally improves population health by moderating the underlying genetic risk of being obese/depressed through gene-environment (GxE) interactions. GxE interactions occur when the effect of genetic risk varies across the environment. The influence of genetic predisposition towards the likelihood of being obese may differ by educational attainment. A college graduate with a high genetic risk of being obese may never be obese because education is associated with higher income affording the individual to eat healthier and having peers who are conscious about leading a healthy lifestyle. In contrast, a high school dropout with a high genetic risk is more likely to be obese because he/she has a low income, is more likely to consume fast food, and interacts with peers who are obese. The proposed project will apply instrumental variables using quasi-experimental variation in educational attainment arising from the Easter School Leaving (ELR) rule. The use of quasi-experimental variation will, under certain assumptions, produce estimates that are not confounded by (i) the influence of unobserved factors that are correlated with education and health, (ii) reverse causality, (iii) gene-environment correlations, and (iv) population stratification, and these estimates can therefore be given a causal interpretation conditional on these assumptions. This research will make important contributions to our understanding of the relations between education and obesity, and depression, and how heterogeneities reflected in gene-environmental interactions shape those relations. The project will last 36 months.