Document Type
Article
Publication Date
7-23-2025
Abstract
Background: The Tsimane and Moseten of the Bolivian Amazon are highly physically active and exhibit low rates of cognitive impairment and brain atrophy.
Methods: We use structural equation modelling to examine how their physical activity levels mediate the relationship between (1) age and cognition, and (2) age and cognition via brain volume (BV).
Results: Tsimane males (n = 305, mean ± SD age = 59.94 ± 9.68) and Tsimane females (n = 265, mean ± SD age = 59.28 ± 9.79) exhibit significantly higher levels of physical activity than Moseten males (n = 106, mean ± SD age = 58.15 ± 9.93) and Moseten females (n = 96, mean ± SD age = 56.63 ± 9.69). Physical activity significantly mediates the relationship between age and cognition in Tsimane males (indirect effect estimate β = −0.01, P < .01) and Tsimane females (indirect effect estimate β = −0.04, P = .01), but not in Moseten males or females.
Conclusions: Among Tsimane males, who are more physically active than Tsimane females, the association between age and cognition via BV is significantly mediated by physical activity. Among Tsimane females, mediation occurs directly via physical activity, bypassing BV. These results suggest that mechanisms of cognitive differences across ages differ by sex and population. Studying the relationship between brain atrophy and lifestyle in nonindustrialized populations elucidates biological and environmental correlates of brain health.
Recommended Citation
Imms, P., Chaudhari, N. N., Cummings, D., Eid Rodriguez, D., Barisano, G., Hooper, P. L., Sayre, M. K., Seabright, E., Thompson, R. C., Sutherland, M. L., Sutherland, J. D., Trumble, B. C., Gurven, M., Stieglitz, J., Finch, C. E., Kaplan, H. S., Mack, W. J., Gatz, M., & Irimia, A. (2025). Physical activity mediates age differences in cognition among Tsimane forager-horticulturalists. The Journals of Gerontology: Series A, Volume 80, Issue 8, August 2025, glaf163. https://doi.org/10.1093/gerona/glaf163
Supplementary data
Peer Reviewed
1
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The authors
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Comments
This article was originally published in The Journals of Gerontology: Series A, volume 80, issue 8, in 2025. https://doi.org/10.1093/gerona/glaf163