SECTION 4
Looking Ahead
Epigenetics: One Intersection of Biology with Sociopolitical Determinants of Health Despite the many ways in which new scientific developments like precision medicine threaten to entrench biological racism, new fields such as epigenetics, developmental origins, and life course research are contributing to our understanding of how racism, not race, has biological effects on the body. Epigenetics and other biopsychosocial fields are pulling together biology, psychology, and upstream determinants of health to answer how racism “gets under the skin,” showing how the social and structural determinants of health (mediated or created by racism) can literally embed themselves in our cells. Research in the developmental origins of disease has shown that the first one thousand days after conception (up to age two) is a critical period in which the developing fetus and child’s cells are most susceptible to outside influences. During this period, the fetus grows from one cell to trillions, so any early changes in these cells will be replicated and reproduced for the entirety of one’s life. Thus, exposures in the uterine environment and early childhood environment can either be protective or increase the risk of developing chronic diseases in adulthood. Literature shows, for example, that low childhood socioeconomic status both increases the physiological response to stressors and increases the reactivity to social support.152 That is, growing up poor can both increase the body’s stress response and increase the body’s ability to calm down or resists those responses in the presence of social support. Furthermore,
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certain exposures during this critical or sensitive period have been shown to increase the risk of type 2 diabetes, stroke, heart disease, some cancers, impaired cognitive function, and mental health issues. The exposures posited to increase chronic disease risk in adults include environmental exposures, such as toxins and pesticides, but also “normal” or endogenous exposures produced by the mother and transmitted to the fetus in utero.153 Although the majority of literature has focused on the effects of cortisol, the stress hormone that acts as a danger signal for the growing fetus, there is also a role of environmental racism (a form of structural racism) that increases exogenous exposures. These articles posit that the more stress a mother is under during pregnancy (including overt physical and mental, as well as more subtle or everyday stressors, such as racist microaggressions), the more cortisol reaches the cells of the fetus. This is also referred to as the mother’s “allostatic load,” or amount of biochemical response to stress. Over time, a constantly high allostatic load can cause the stress response to stay on permanently. High allostatic load impacts neuroendocrine, cardiovascular, immune, and metabolic systems, in turn contributing to various forms of damage, including cardiovascular disease, neurological atrophy, psychiatric symptoms, mortality, mobility limitations, cognitive decline, and functional impairments.154 The fetus interprets high levels of cortisol in utero as a signal that the postnatal environment will be stressful, and reprograms the developing stress response systems to stay on high alert with a short fuse, as well as inhibit the
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