1. Hertzmann and Boyce argue that “it is not genes or environment, nor is it genes and environment, but rather it is gene-by-environment interactions that influence developmental trajectories.” To what extent do you think that GxE interactions can contribute to major disparities along racial/ethnic, socioeconomic, or geographic dimensions? Please consider this both in general and in respect to your particular area of interest.
Life course patterns involving dynamic systems that predicate the accumulation and interaction of exposures over time, lead me to believe that gene-by-environment interactions contribute to health disparities. It is difficult to disentangle how much one contributes over the other, but through Hertzmann and Boyce’s argument, I can understand how some pathways are triggered by gene-by-environment interactions over gene-only effects. Exposures to stressors and living in disadvantageous socioeconomic circumstances, augments risk for disorders through heightened susceptibility. An example provided in the reading, explains how daily encounters with racial and socioeconomic discrimination can accelerate aging processes and lead to the premature onset of age-related disease. Unless the cycle is broken, the extent to which disparities are maintained based on socioeconomic, racial, and geographic dimensions is evident. The unknown cause of uterine fibroids among premenopausal women, makes it hard to understand what genetic or environmental interactions are at play. However, given their outstanding prevalence among women of color, and the heightened severity of their symptoms as a result of them, it is likely that toxic environmental exposures (i.e diet, stress,radiation, etc.) are major contributors.
2. Discuss implications of epigenetic mechanisms of disease for intergenerational effects on health disparities, as well as for interventions designed to address health disparities.
The influence of SES and race/ethnicity on long-term human developmental outcomes and the expression of gradients in human development is eye-opening. Examples of epigenetic mechanisms related to the HPA axis and its accompanying secretion of cortisol in the development of memory, attention, and other cognitive processes, shows systematic differences according to parental income, education, and employment status. De Mendoza’s article on how African American women who reported greater perceived discrimination had decreased DNAm on seven genes/CpG sites, supports intergenerational effects on health disparities. It is worth examining how life experiences continue to affect the epigenome, but also looking to maintain our focus on interventions directly related to the environment, specifically during early windows of opportunity in brain and biological development to properly promote health equity.
3. Discuss how the findings in the Robinette paper relate to socioecological model we are using in this course – e.g. briefly describe how the different levels displayed in this model are related to each other in this paper.
Robinette et. al paper thoroughly examines the distinct interplay of individual and neighborhood SES on allostatic load. At the organizational level of the socioecological model, it is observed that neighborhoods with impoverished physical and social environments, equates to less social engagement and poorer health behaviors among its inhabitants. From this perspective, a downstream effect follows, with an impact on social networks and individual behaviors. By situating the lived stressors of those in low SES neighborhoods, it is obvious that individual behaviors/tendencies (i.e. anxious arousal, exercise habits, smoking, and the consumption of fast food) are a response to one’s surroundings. Although neighborhood cohesion (community in the socioecological model), was not significant predictor of allostatic load, allostatic load was significantly higher among individuals living in neighborhoods perceived as unsafe. I am interested to know how these findings can be applied to international populations and younger groups of people.