Aaron Blackwell: UCSB Department of Anthropology

The Shuar are a large and semi-autonomous indigenous group from the Amazonas region of Ecuador. Most Shuar subsist on a mixture of foraging and horticulture, but increasingly Shuar in many areas are becoming integrated with market economies. This talk presents fieldwork conducted amongst the Shuar between 2005 and 2009, with comparative data from the Shiwiar of Ecuador, non-indigenous Ecuadorian colono children, the Tsimane of Bolivia, and the 2005-2006 U.S. NHANES. I examine how growth and immune function are affected by market integration, household composition, and changes in pathogen exposure. Compared to the more traditionally living but closely related Shiwiar, Shuar show a higher prevalence of growth stunting. Between individuals, growth stunting is related to markers of immune activation, particularly as related to helminth infection. Biomarkers of helminth infection are associated with poorer growth in children, lower stature in adults, and decreases in inflammatory biomarkers. These results suggest that infection with parasites, such as helminths, may have hidden costs associated with changes in the allocation of resources between the competing demands of immune function and growth. In addition, higher biomarkers of helminth infection are associated with the presence of additional children in a household, suggests children in large families may face increased pathogen transmission as well as potential competition for limited parental resources.
http://www.bec.ucla.edu/BlackwellPaperFinal.pdf