Scientists identify ‘sweet spot’ of brain aging

X-rays of neuron brain activity

Indigenous lowland communities in Bolivia, such as the Tsimané and Mosetén, have some of the lowest rates of heart and brain disease due to optimal levels of food intake and exercise. New research indicates that the lifestyles of these communities, which balance daily exertion and abundance of food, contribute to healthy brain aging and reduced disease risk.

Indigenous communities residing in the lowland rainforests of Bolivia have reported some of the lowest rates of heart and brain disease in recorded scientific history. Now, USC-led research in the Tsimané and Mosetén communities indicates that a balanced combination of food intake and physical activity can maximize healthy brain aging and reduce the risk of disease.

The study has just been published in the journal Proceedings of the National Academy of Sciences.

The advent of industrialization brought many benefits, including increased availability of food, reduced physical exertion, and better access to health care. However, our current lifestyle has also resulted in a lack of exercise and over-consumption of food, leading to an increase in obesity. Unfortunately, this sedentary lifestyle and obesity are linked to smaller brain volumes and faster cognitive decline.

To better understand the tipping point where abundance and ease begin to harm health, researchers recruited 1,165 adult Tsimané and Mosetén, ages 40 to 94, and provided transport for participants from their remote villages. to the nearest hospital with CT scan equipment.

Tsimane Woman and Child

The Tsimané have some of the lowest rates of heart and brain disease in the world. Credit: Tsimane Health and Life History Project Team

The team used CT scans to measure brain volume by age. They also measured the participants’ body mass index, blood pressure, total cholesterol and other markers of energy and overall health.

The researchers found that the Tsimané and Mosetén people experience less brain atrophy and better cardiovascular health compared to industrialized populations in the United States and Europe. Rates of age-related cerebral atrophy, or brain shrinkage, are correlated with risks of degenerative diseases like dementia and Founded in 1880, the University of Southern California is one of the world's leading private research universities. It is located in the heart of Los Angeles.

” data-gt-translate-attributes=”({” attribute=””>USC Leonard Davis School of Gerontology and corresponding co-author of the study. “Humans have historically spent a lot of time exercising out of necessity to find food, and their brain aging profiles reflected this lifestyle.”

The Mosetén: a bridge between pre- and post-industrialized societies

The results also illustrated the main differences between the two Aboriginal societies. The Mosetén are a “sister” population to the Tsimané in that they share similar languages, ancestral history, and a subsistence lifestyle. However, the Mosetén are more exposed to modern technology, medicine, infrastructure and education.

“The Mosetén are an important intermediate population that allows us to compare a wide range of lifestyle and health care factors. It is more advantageous than a simple comparison between the Tsimané and the industrialized world,” said Irimia.

Irimia said that along this continuum, the Mosetén showed better health than modern populations in Europe and North America – but not as good as that of the Tsimané.

Among the Tsimané, surprisingly, BMI and slightly higher levels of “bad cholesterol” were associated with larger brain volumes for age. However, this may be because individuals are more muscular, on average, than individuals in industrialized countries who have a comparable BMI.

Still, the Tsimané and Mosetén are approaching the “sweet spot,” or the balance between daily exertion and plenty of food, which the authors say may be the key to healthy brain aging.

The future of preventive medicine rests on an understanding of the evolutionary past of man

The study authors explained that people living in societies with plentiful food and low demands on physical activity face a conflict between what they consciously know is best for their health and cravings. , or drives, that stem from our evolutionary past.

“Over our evolutionary past, more food and fewer calories expended to obtain it have led to improved health, well-being, and ultimately higher reproductive success or Darwinian fitness,” notes Hillard. Kaplan, a professor of health economics and anthropology at Chapman University who has studied the Tsimané for nearly two decades. “This evolutionary history was selected for psychological and physiological traits that made us crave extra food and less physical labor, and with industrialization these traits caused us to overstep the mark.”

According to Irimia, the best place to be in terms of brain health and disease risk is the “sweet spot” where the brain doesn’t get too little or too much food and nutrients, and where you get plenty of exercise. .

“This ideal set of conditions for disease prevention prompts us to ask whether our industrialized lifestyles are increasing our risk of disease,” he said.

Reference: “Brain Volume, Energy Balance, and Cardiovascular Health in Two Nonindustrial South American Populations” by Hillard Kaplan, Paul L. Hooper, Margaret Gatz, Wendy J. Mack, E. Meng Law, Helena C. Chui, M. Linda Sutherland, James D. Sutherland, Christopher J. Rowan, L. Samuel Wann, Adel H. Allam, Randall C. Thompson, David E. Michalik, Guido Lombardi, Michael I. Miyamoto, Daniel Eid Rodriguez, Juan Copajira Adrian, Raul Quispe Gutierrez, Bret A. Beheim, Daniel K. Cummings, Edmond Seabright, Sarah Alami, Angela R. Garcia, Kenneth Buetow, Gregory S. Thomas, Caleb E. Finch, Jonathan Stieglitz, Benjamin C. Trumble, Michael D. Gurven, and Andrei Irimia, March 20, 2023, Proceedings of the National Academy of Sciences.
DOI: 10.1073/pnas.2205448120

The study was funded by the National Institute of Aging, the National Science Foundation and the French National Research Agency – Investissements d’Avenir.

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