Brigitte M. Holt, associate professor of anthropology at the University of Massachusetts Amherst, was recently awarded a three-year, $788,810 National Science Foundation grant to examine whether greater physical activity levels lead to greater bone strength and protect against age-related bone loss. Holt will serve as co-principal investigator of the study along with Jonathan Stieglitz, assistant professor at Université Toulouse 1 Capitole and program director of the Institute for Advanced Study in Toulouse, France.
The research, to be conducted on the indigenous Tsimane people of lowland Bolivia, is the first to study the association between activity profiles and bone structure in a living pre-industrial population. Holt and Stieglitz will also examine the extent to which osteogenic responses to habitual, physically intensive subsistence tasks are mediated by older age, gender differences, energy limitation and high pathogen burden.
“We hope that our findings will have implications for understanding the causes of osteoporosis, a massive global public health challenge, by identifying the risk factors for low bone mass beyond sedentary lifestyle,” Holt says. “By providing knowledge of direct epidemiological relevance for Tsimane and other rural subsistence populations in the early-to-mid stages of modernization, this project will provide a baseline dataset that can be used by Bolivian and other government officials for future health service planning.”
The study has four main aims: imaging and measurement of bone structure for multiple bones; measurement of activity profiles to examine the effects of physical activity levels on bone structure; examine moderators of the relationship between activity profiles and bone structure including individual-, family- and village-level factors; and document the prevalence and structural correlations of low bone mass. The researchers will utilize peripheral quantitative computed tomography (pQCT) to measure bone structure, quantitative ultrasonography (qUS) to further assess bone microarchitecture, structured interviews to assess diet, and a combination of accelerometry, heart-rate monitoring, GPS, behavioral observation and interviews to assess activity profiles.
The project will employ four Tsimane research assistants and will provide research and funding opportunities for graduate and undergraduate students.
Holt has 20 years of experience in prehistoric and historic human bone imaging analysis, and Stieglitz, currently a co-director on the Tsimane Health and Life History Project (THLHP), has worked with the Tsimane for 13 years.
“Given the project’s scope and integration with the THLHP, it is highly unlikely that a similar bone dataset will ever again be assembled in a pre-industrial population,” Holt says. “At the end of the project, we will make publicly available all anonymized data to qualified researchers, which will serve as an archive for future scientists no longer able to study impacts of modernization on activity profiles and bone structure in populations undergoing socioeconomic change.”