With a progressive aging of the world’s population and an ever-increasing increase in dementias, researchers are trying to find imaginative solutions to deal with this serious problem. And it’s possible that taking a look at how our ancestors lived might help us find answers.
According to new research from the University of Southern California, following a much healthier, pre-industrial lifestyle may hold clues to preventing Alzheimer’s disease and other dementias.
1% of tribal seniors Tsimane and Moseten suffers from dementia. In contrast, 11% of those aged 65 and over living in the US or Europe have dementia.
“Something regarding their pre-industrial subsistence lifestyle seems to protect the Tsimane and Moseten of dementia,” says Margaret Gatz, the study’s lead author and a professor at the
University of Southern California.
The researchers used images of computed tomography Brain CT scans, cognitive and neurological assessments, and culturally appropriate questionnaires, facilitated by a local team of trained translators and Bolivian doctors, to diagnose dementia and cognitive decline among the Tsimane and Moseten.
The study found only five cases of dementia among 435 Tsimane people and only one case among 169 Moseten aged 60 years or older.
In the same age groups over 60, the team diagnosed regarding 8% from Tsimane and 10% from Moseten with mild cognitive impairment, which is usually characterized by an early stage of memory loss or decline in other cognitive abilities, such as language or spatial perception.
The researchers were surprised to find that study participants with dementia or mild cognitive impairment frequently they had unusual and prominent calcifications of their intracranial arteries. These study participants frequently displayed parkinsonian symptoms during neurological exams and cognitive deficits in attention, spatial awareness, and executive functioning.
Although calcifications were more common among people with cognitive impairment, the scientists also looked at these vascular calcifications in CT scans of people without dementia or mild cognitive impairment.
However, they point out that more research is needed to understand the role of vascular factorsas well as infectious and inflammatory disorders, which are very common in these populations, along with other risks of dementia.
The approximately 17,000 Tsimane remain physically very active throughout their lives, as they fish, hunt and farm with hand tools and gather food from the forest. The 3,000 Moseten also reside in rural villages and engage in subsistence farm work. Unlike the more isolated Tsimane, they live closer to cities and have schools, access to clean water and medical services, and are more likely to be literate.
The authors ofThe study compared their results with a systematic review of 15 studies of indigenous populations in Australia, North America, Guam, and Brazil.. That review found a prevalence of dementia ranging from 0.5% to 20% among indigenous older adults.
The fact that indigenous populations in other parts of the world have high rates of dementia may be due to a greater amount of contact and adoption of lifestyles from their non-indigenous neighbors. They also have higher risks of diabetes, hypertension, alcohol abuse, obesity, and cardiovascular disease.
These dementia risk factors are extremely low among the Tsimane and Moseten populations.
the researcher Margaret Salt tells ABC Salud that they hope continued research “will identify some combination of genetic, environmental, and lifestyle causes for the low rate of dementia in this population.”
These populations, he adds, “allow us to look at health as it might have been among our human ancestors, where their physically active subsistence lifestyle and healthy hearts are just one difference.”
Previous research published in
«The Lancet» showed that the Tsimane have remarkably healthy hearts in old age and a lower prevalence of coronary atherosclerosis (a disease that manifests as fatty deposits within the arteries) of any population known to science. This distinction may be related to their subsistence lifestyle.
Another work published last year in
«The Journal of Gerontology»led by the same university assistant professor Andrei Irimia, also a co-author of the new publication, found that the Tsimane experience less brain atrophy than their American and European peers.
The researchers say that, in contrast to the Tsimane, lifestyle factors in higher-income countries, including lack of physical activity and diets high in sugars and fats, contribute to heart disease and may also accelerate aging. cerebral.
Aging is the most important known risk factor for Alzheimer’s and other dementias. The evidence points to the downside formal education, midlife hypertension and diabetes, cardiovascular disease, physical inactivity and, more recently, air pollution as major modifiable risk factors for dementia and Alzheimer’s disease.
The aging of the world population, together with the proliferation of these modifiable risk factors, will lead to a tripling of the number of people with dementia worldwide for 2050, to more than 152 million.
“We are in a race to find solutions to the increasing prevalence of Alzheimer’s disease and other dementias,” he says. Hillard Kaplanco-author of the study and professor at the
Chapman University (USA), who has studied the Tsimane for two decades. “Looking at these diverse populations increases and accelerates our understanding of these diseases and generates new insights.”
Gatz says that if “we compare the brains of cognitively healthy people with the brains of people who have developed dementia, we may be able to work backwards to see what might cause changes in the brain.”
For example, he explains, “if people with hypertension have brain differences from people without hypertension, and those brain differences are associated with dementia, we can infer that the treatment of hypertension is important for healthy brain function».
“Working with populations like the Tsimane and the Mosetenwe can gain a better understanding of global human variation and what human health was like in different settings before industrialization,” he explains. Benjamin Trumbleco-author of the study and professor at the
Arizona State University.
“What we do know,” he concludes, “is that the sedentary, urban and industrial life it is quite novel compared to the way our ancestors lived for more than 99% of humanity’s existence.”
But Laura Perez Gilthe
Department of Anthropology. Federal University of Parana (Brazil) what is missing in this interpretation is that it does not make “allusion to the role that the forms of social relationship can play in the mental health of the Tsimane”.
Indigenous groups seek the «good living», which means living with relatives, avoiding conflict, living quietly, having parties, working to have abundant food. «You live with another rhythm, what is going to be consumed at the moment is produced; For this reason, he tells us, I suspect that the specific way in which social relationships develop, the rhythm of life, the daily relationship with the natural environment (going hunting, fishing, walking, looking for food on the farm… .) the disconnection of social networks, technology, etc., has an impact on the mental health of people and, I imagine, on the health of people when they age ».
Therefore, he believes it is also important to understand how all these factors affect the preservation of mental health, although this, he says, “does not nullify the results of the article.”
