Margaret Gatz, University of Southern California
Wendy J. Mack, University of Southern California
Helena C. Chui, University of Southern California
E. Meng Law, Monash University
Giuseppe Barisano, University of Southern California
M. Linda Sutherland, MemorialCare Health Systems
James D. Sutherland, MemorialCare Health Systems
Daniel Eid Rodriguez, San Simon University
Raul Quispe Gutierrez, Tsimane Health and Life History Project, Bolivia
Juan Copajira Adrian, Tsimane Health and Life History Project, Bolivia
Jesus Bani Cuata, Tsimane Health and Life History Project, Bolivia
Amy R. Borenstein, University of California, San Diego
Ellen E. Waters, University of Southern California
Andrei Irimia, University of Southern California
Christopher J. Rowan, Renown Institute for Heart and Vascular Health
L. Samuel Wann, University of New Mexico
Adel H. Allam, Al-Azhar University, Egypt
Randall C. Thompson, St. Luke’s Mid America Heart Institute of Kansas City
Michael I. Miyamoto, Providence Health
David E. Michalik, Miller Children’s and Women’s Hospital Long Beach
Daniel K. Cummings, Chapman University
Edmond Seabright, University of New Mexico
Angela R. Garcia, Arizona State University
Paul L. Hooper, University of New Mexico
Thomas S. Kraft, University of California, Santa Barbara
Caleb E. Finch, University of Southern California
Gregory S. Thomas, MemorialCare Heart & Vascular Institute, Fountain Valley
Jonathan Stieglitz, Institute for Advanced Study in Toulouse
Benjamin C. Trumble, Arizona State University
Michael D. Gurven, University of California, Santa Barbara
Hillard Kaplan, Chapman UniversityFollow

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We evaluated the prevalence of dementia and mild cognitive impairment (MCI) in indigenous Tsimane and Moseten, who lead a subsistence lifestyle.


Participants from population-based samples ≥ 60 years of age (n = 623) were assessed using adapted versions of the Modified Mini-Mental State Examination, informant interview, longitudinal cognitive testing and brain computed tomography (CT) scans.


Tsimane exhibited five cases of dementia (among n = 435; crude prevalence = 1.2%, 95% confidence interval [CI]: 0.4, 2.7); Moseten exhibited one case (among n = 169; crude prevalence = 0.6%, 95% CI: 0.0, 3.2), all age ≥ 80 years. Age-standardized MCI prevalence was 7.7% (95% CI: 5.2, 10.3) in Tsimane and 9.8% (95% CI: 4.9, 14.6) in Moseten. Cognitive impairment was associated with visuospatial impairments, parkinsonian symptoms, and vascular calcification in the basal ganglia.


The prevalence of dementia in this cohort is among the lowest in the world. Widespread intracranial medial arterial calcifications suggest a previously unrecognized, non-Alzheimer's disease (AD) dementia phenotype.


This article was originally published in Alzheimer's & Dementia in 2022.

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This work is licensed under a Creative Commons Attribution-Noncommercial-No Derivative Works 4.0 License.