In Bolivia, no cases of Alzheimer’s were detected among 700 senior Tsiman and Mosetenes people.
The Tsimané and Moseten peoples, two groups living in the Bolivian Amazon rainforest, have significantly lower rates of dementia than those observed in Europe and the United States, according to a study reported on September 28, 2026. Researchers found no signs of Alzheimer’s disease among those examined. Their lifestyle may contribute to this difference, but the available evidence does not establish a causal link.
A study conducted among people over 60 years old
Approximately 16,000 Tsimanés and Moseten live in small villages, according to the study’s presentation. Among them, 700 people over the age of 60 participated in a follow-up that lasted nearly five years.
Researchers, an American team of anthropologists, biologists, and physicians, report dementia rates three to four times lower than those mead in Europeans or Americans. They also indicate that they observed neither the clinical symptoms nor the biomarkers associated with Alzheimer’s disease in the groups studied. The disease is characterized by marked memory impairment and can be studied using markers such as beta-amyloid peptides.
An aging process that has already been studied
These results are consistent with previous work on the aging of the Tsimané people. Cardiovascular research had revealed a particularly low risk of coronary heart disease among them. Other studies had estimated that their brain volume decreased on average 70% more slowly than that of Western populations.
The new study focuses more specifically on dementia and Alzheimer’s disease. It adds a new element to the observation of healthy aging in these populations, without, however, fully explaining the mechanisms involved.
Lifestyle, a path being explored
The researchers also examined genetic factors. They noted the presence of the APOE epsilon 4 variant, associated with an increased risk of dementia or mild cognitive impairment. However, the study’s presentation does not identify genetics as the primary explanation for the low rates observed.
Lifestyle is another possible explanation. Previous studies indicated that the Tsimanés spend only 10% of their waking hours engaged in sedentary activities. Their diet, described as high in fiber and low in processed foods, as well as their physical activity, could play a role. The source also suggests that obesity, hypertension, and diabetes are less prevalent in these populations.
These characteristics are presented as factors that may contribute to their protection against Alzheimer’s. They do not demonstrate that lifestyle alone explains the absence of cases reported in the study.
Source: Ecology (www.radiofrance.fr)
Original article: See the original source
