In Bolivia, on the periphery of the Amazon jungle, the Tsimane tribe lives in isolation. They get old differently from other people. In 2017, scientists found they have the healthiest hearts in the world. Researchers have now learned that Tsimane’s brain volume decreases much more slowly with age than that of Americans or Europeans. The probable reason is the way of life of the Indians, writes ScienceAlert.
The study involved 746 tsimane aged 40 to 94 years. Scientists made a computed tomography and compared the results of the scan with data obtained during the survey of people in Hamburg, St. Louis and Rotterdam.
It turned out that the brain volume of people’s leading an industrial lifestyle – like residents of cities and megalopolises – decreases 70% faster than that of tsimane. Scientists emphasize: this figure should be considered as approximate – the statistics had a number of limitations.
“Still, this is evidence of a significant and striking contrast in the brain health of aging Cymanes and their peers in the United States and Europe,” the researchers say.
Slower brain atrophy reduces the risk of cognitive impairment in old age, primarily dementia. Such a feature of the tsimane organism may be associated with the same factors that determine the good health of their cardiovascular system. This is diet and activity.
A 2017 study found that the diet of Cymane is 72% carbohydrates, 14% fat, and the same amount protein. The average American, for example, has 52%, 34%, and 14% ratios on a plate.
The difference is that for Indians, the source of protein is lean meat, while for US residents, less healthy foods. Tsimane also eat a lot of fiber-rich foods.
In addition, the Indians are physically active 4-7 hours a day: they hunt, fish, gather.
“Tsimane showed us the results of an amazing natural experiment to track the potentially damaging effects of modern lifestyles on our health,” said Andrei Irimia, a neuroscientist at the University of Southern California.
The tribe still lives by traditional means – farming, hunting, gathering and fishing – and continues the practices of its ancestors, created long before industrialization and urbanization transformed much of the world.
On the one hand, the traditional way of life and the lack of access to modern medical services and medical care expose them to a greater burden of infectious diseases and a higher level of inflammation as a result. New results provide an answer to this paradox. Scientists suggest that cardiovascular health is ultimately more important for healthy brain aging than inflammatory factors associated with infectious diseases.
“Our sedentary lifestyle and diet high in sugar and fat can accelerate the loss of brain tissue with age and make us more vulnerable to diseases such as Alzheimer’s disease. Tsimane can be a model of healthy brain aging,” said senior author and anthropologist Hillard Kaplan of Chapman University, who has studied cimans for nearly two decades.