Does Lifestyle Affect Stress in the Turkana?

Abstract

Evolutionary approaches have been used to illuminate the sociological phenomenon of social determinants of health, weathering, and acculturation in minority or immigrating populations. They provide a theory of human adaptation to an environment of stressors, involving HPA axis modification over time, measured by proxy of stress levels. It is expected that as environmental stressors increase, stress levels are modified, and the result is poor health outcomes. This thesis zooms into the relationship between health outcomes and lifestyle, using plasma cortisol concentration as a proxy for HPA axis modification to see if lifestyle affects stress. In collaboration with the Turkana Health and Genome Project, it builds off previous studies that have shown that urban versus pastoralist Turkana exhibit greater markers of cardiovascular disease. This study shows that the likelihood of lifestyle affecting stress is not significant, and thus, lifestyle does not affect stress in the Turkana. The implications of this study are important for understanding both evolutionary adaptation and human health, bringing into question whether or not the Turkana are a population undergoing changes significant enough to demonstrate acculturative stress. More research can be done to improve the accuracy of this experiment, by increasing sample size, and measurement accuracy. Interdisciplinary studies between sociological acculturation and evolutionary biology may prove relevant for targeted health intervention for the changing lifestyles of the Turkana in Turkana county and beyond.