Shuar Health & Life History Project
About the Project
The Shuar Health and Life History Project (SHLHP) is a multi-faceted research project that examines the ecology and health of the Indigenous Shuar, as well as non-Indigenous Ecuadorians (Colonos), from the Morona-Santiago region of Ecuador. For more information on the participant population and field site, click here. Traditionally forager-horticulturalists, Shuar currently experience a wide range of market integration (i.e., the degree of production for and consumption from a market-based economy) across their territory. This process provides an important opportunity to examine how economic, social, and dietary changes associated with market integration affect life history trade-offs and how those trade-offs affect health.
This field site also allows examination of particular aspects of market integration, predicted life history changes, and actual behavior and health across a wide range of conditions within the same ethnic group. Additionally, comparison of Upano Valley Shuar, who are currently more market integrated, with their Colono neighbors provides an opportunity to examine the same variables among people from a different cultural background living under similar socio-ecological conditions. Through this work, the SHLHP has documented that there are multifaceted contributors -- biological, developmental, cultural, and environmental -- that structure chronic and infectious disease risk among the Shuar.
The SHLHP is committed to respectful, ethical, and mutually beneficial work with Shuar communities. Our research emphasizes the importance of engaging participant communities and Shuar leadership while working to translate and disseminate research findings in accessible and sustainable ways. We continuously strive to shape opportunities that empower Shuar communities to participate in and effect decisions about the research process and future research directions. We feel strongly that our project and the field of biological anthropology must engage in dialogue with Indigenous communities and find new ways to build lasting partnerships.
The aims of the SHLHP are threefold:
First, the project investigates how cultural and economic changes in the region affect Shuar health and well-being. One component of this research focuses on growth and nutritional status in Shuar children. We have compared Shuar children to other populations and have examined risk factors for poor growth and development. After more than 10 years of research, we have amassed a considerable amount of data on growth and development. These results were first described in Blackwell et al. 2009. Several more recent publications on Shuar growth, based on a large sample (n=2,463), highlight that growth among the Shuar differs substantially from international references and is characterized by rapid early postnatal growth, an early female pubertal growth spurt, and extended male growth into young adulthood (Urlacher et al., 2016a, 2016b, 2016c).
Project co-directors Drs. Felicia Madimenos and Melissa Liebert cooking with a Shuar friend.
Another area of research is skeletal health and risk for osteoporosis. This research, led by Dr. Felicia Madimenos, has examined the reproductive and lifestyle factors that influence bone density. Results of this research are detailed in several papers (Madimenos et al. 2011; Madimenos et al. 2012). Also, check out the profile on the Scientific American blog, which provides a nice summary of the article and also describes the Shuar project as “well known within anthropology for its rigorous methodology and outreach with local participants. It’s also an interdisciplinary site that seems to be great for tackling both biological and cultural anthropology questions.” More recent papers look at bone density among Colonos (Madimenos et al. 2015) and compare and contrast Shuar skeletal health with the Indigenous Tsimane of Bolivia (Madimenos et al. 2020). These studies demonstrate that current understanding of the factors shaping skeletal health can be augmented by focusing on heterogenous populations with active lifestyles.
We are also examining the effects of social change on other chronic conditions such as cardiovascular disease and diabetes and are investigating the role of physical activity, chronic psychosocial stress, and diet in shaping disease patterns among Shuar. In Annals of Human Biology, Liebert et al. 2013 describes the effects of market integration on cardiovascular and metabolic diseases, concentrating on factors like proximity to town and consumption of market foods and their role in shaping risk markers such as blood pressure, lipids, and glucose. This work provides evidence that market integration among Shuar is not a uniformly negative process but instead produces complex and nuanced cardiovascular and metabolic health outcomes. More recently, we have found evidence for similar complex relationships between market integration and nutritional status among Shuar children (Urlacher et al., 2016). Additional work by Dr. Melissa Liebert explores the effects of market integration on biological indicators of the human stress response, including diurnal cortisol activity and immune function, and their role in chronic disease risks.
We have recently begun to consider how social and environmental change alters the human microbiome, linking specific aspects of market integration (e.g., housing construction and ownership of subsistence items) to shifts in the microbiome (Stagaman et al., 2018). Findings suggest that even within a single ethnicity living in a constrained geographic region, the early stages of market integration affect the diversity and composition of the gut microbiome. More detailed analyses are currently underway.
Project co-director Dr. Sam Urlacher using a portable knemometer to monitor the short-term growth of a Shuar girl
Dr. Aaron Blackwell measuring the body fat of a Shuar boy (left); American Journal of Human Biology cover from Nov/Dec 2009 highlighting SHLHP work (right)
Dr. Tara Cepon-Robins preparing fecal samples for analysis of parasitic worms.
Second, the project is using the branch of evolutionary biology known as life history theory to investigate how lifetime phenotype and health are shaped by underlying variation in energy allocation to competing life tasks (i.e., maintenance, growth, reproduction and physical activity). These findings were initially detailed in a series of publications by Dr. Aaron Blackwell in the American Journal of Human Biology (Blackwell et al. 2010) and PLoS Neglected Tropical Diseases (Blackwell et al. 2011). Recent research led by Dr. Sam Urlacher has used cutting-edge immune biomarker methods to demonstrate that immune activity is associated with strong trade-offs resulting in growth faltering among Shuar children across timescales that range from days to years (Urlacher et al. 2018). More recently, work headed by Urlacher - involving direct measurements of energy expenditure using state-of-the-art doubly labeled water and respirometry methods - found evidence that Shuar children experience elevated basal metabolism but do not spend more total calories each day than children living in the U.S. and U.K. (Urlacher et al. 2019). This finding suggests that children's total energy expenditure is constrained across lifestyles and environments, a finding likely mediated by underlying trade-offs involving immune activity. These results are important not only for understanding children's growth and development, but also for understanding basic principles of human energy requirements, the causes of obesity, and for informing public health strategies to prevent both undernutrition and overnutrition.
The SHLHP has also investigated the relationship between markers of immune function/inflammation (e.g., immunoglobulin E [IgE] and C-reactive protein [CRP]) and several measures of cardiovascular and metabolic health (e.g., fasting glucose and lipids). This research suggests important trade-offs between immune responses and different aspects of cardiovascular and metabolic health (Liebert et al. 2013; Urlacher et al., 2018, 2019). The project has collaborated with Dr. Thom McDade and former Northwestern graduate student Paula Tallman on an NSF-funded ecological immunology project that investigated CRP variability within the context of this non-industrialized, high infectious disease environment. The findings were described in an article in the American Journal of Human Biology (McDade et al. 2012), and illustrate that CRP is highly variable over time with no evidence of chronic subclinical elevation among Shuar. These results have important implications for research on inflammation and diseases of aging globally, as well as for scientific understandings of the regulation of inflammation.
Drs. Tara Cepon-Robins and Theresa Gildner expanded this research by examining how parasite burden structures life history trade-offs, and how shifting patterns of infectious disease exposure alter risk for allergies and autoimmune diseases. Dr. Cepon-Robins led a recent research effort--published in the Journal of Parasitology--that examines the prevalence and infection intensity of parasitic worms among geographically and economically distinct Shuar communities (Cepon-Robins et al. 2014); this research was refined in a recent article in the Journal of Physiological Anthropology (Gildner et al. 2016). Additional research, published in the American Journal of Physical Anthropology, documented levels of intestinal inflammation (using fecal calprotectin) and connected these to measures of soil-transmitted helminth infection (Cepon-Robins et al., 2019).
The Shuar project also features prominently in a recently completed NSF-sponsored project led by Dr. Snodgrass and Dr. Geeta Eick (University of Oregon), "Building the Methodological Toolkit in Biological Anthropology: Dried Blood Spot Methods Development for Addressing Key Evolutionary and Biocultural Questions" (BCS-1638786), that focused on the development and validation of new dried blood spots assays for use in population-level research. The project also involves Drs. Cepon-Robins, Sugiyama, and Madimenos. The project, which is being conducted in the Global Health Biomarker Laboratory at UO, focuses on the biomarkers TPOAb (a marker of autoimmune thyroid disorders), carboxylated osteocalcin (cOC; a marker of bone formation), tartrate-resistant acid phosphatase 5b (TRACP5b; a marker of bone resorption), and Klotho (a marker of stress-related aging). These techniques can then be used in the Shuar project to test a variety of research questions, including how parasitic worm exposure is related to the risk of autoimmune disease.
Finally, the project seeks to provide health information to participants and community partners to assist in targeting prevention and treatment efforts. Our research is conducted in collaboration with Ecuadorian medical colleagues and the Shuar Federation. The project facilitates delivery of health information directly to participants, to the Shuar Federation, and to local medical providers in three ways: 1) individual health results are provided and explained to each participant; 2) evidence of pathology is conveyed to local medical workers if the participant desires, and assistance is provided with acquisition of treatment if necessary and feasible; and 3) overall research results and interpretation are presented to Ministry of Health colleagues, the Shuar Federation Health directorate, and participant community meetings to contribute to public health policy. Increasingly, summaries of SHLHP project work are being shared with international organizations to improve the health and well-being of disadvantaged groups throughout the Amazonian region and beyond.
Project founder Dr. Larry Sugiyama weighing a Shuar infant at a collaborating health clinic.
Exemplifying the SHLHP's commitment to improving the welfare of Shuar participants, friends, and colleagues, Drs. Madimenos and Sugiyama received an Engaged Anthropology Grant from the Wenner-Gren Foundation in 2013 ("Engaging Shuar Communities through Collaborative Health Education: Enhancing Participant Agency in Indigenous Health Research"). This award was specifically designed to work with Shuar communities and to conduct a series of workshops, presentations, and family days to disseminate information regarding health issues in the local community. Check out the write-up of the project on the Wenner-Gren website.
The SHLHP has a record of collaborative research and since the inception of this project, SHLHP has made data available to qualified scientists and health practitioners upon request. For more information regarding the data sharing process and our data use agreement policies, refer to our Data Sharing page.