An Amazonian tribe may have discovered the secret to keeping the brain from aging

Putting the very recent effect of COVID-19 aside for a moment, life expectancies in the Western World have steadily increased over time thanks to advancements in modern medicine and science. Dementia and Alzheimer’s rates, however, are trending in the opposite direction.

Each year more and more people are diagnosed with a form of dementia, and by 2050 there will be an estimated near 150 million people living with dementia globally. 

In other words, people living in places like the US and Western Europe are, generally speaking, living longer than ever yet succumbing to brain deterioration at increasingly alarming rates. Clearly, something is amiss from a brain health perspective, and a fascinating new study just released by the University of Southern California may have uncovered the best way to protect our minds with a little help from a tribe in the Bolivian Amazon.

The connection between brain atrophy and an indigenous tribe

Researchers examined the brains of a group of volunteers from the Tsimane indigenous people and discovered that their brains atrophy and experience brain volume loss at a 70% slower rate than the average Westerner. For reference, excessive brain volume loss is considered a major risk factor for dementia, cognitive impairment, and functional decline.

That’s an incredible difference and one that on the surface makes little sense. How could a group of indigenous peoples lacking access to modern medical care be doing so much better in regards to brain aging? Study authors say what the Tsimane lack in technology they make up for with physical activity and diet. Tribe members are “extremely physically active” pretty much all day and usually eat a high-fiber diet including mostly vegetables, fish, and lean meats.

In comparison, a Western lifestyle is much more stagnant and filled with saturated fats. Now, you’ve probably heard countless times that it’s a good idea to move more and eat less processed foods, but those recommendations are always framed as avenues of staying physically fit or improving heart health.

These new findings suggest the right diet and physical activity routine can also keep your mind significantly healthier and younger.

“The Tsimane have provided us with an amazing natural experiment on the potentially detrimental effects of modern lifestyles on our health,” says study author Andrei Irimia, an assistant professor of gerontology, neuroscience, and biomedical engineering at the USC Leonard Davis School of Gerontology and the USC Viterbi School of Engineering. “These findings suggest that brain atrophy may be slowed substantially by the same lifestyle factors associated with very low risk of heart disease.”

A total of 746 Tsimane adults between the ages of 40 and 94 took part in this research. Each person had to undergo a brain scan, but that isn’t exactly easy in the Amazon. So, participants had to take a long journey (two full days in some cases) to Trinidad, the nearest town with a working CT machine.

Those brain scans were used to determine brain volumes and their relationship with age among the Tsimane people. Afterward, those results were compared to CT scans among three populations from either the US or Europe. Near unbelievably, that comparison led to the finding that the difference in brain volumes between middle age and old age is 70% smaller in Tsimane than in Western peoples.

Another finding of particular note is that the Tsimane people did display high levels of inflammation, which is curious because inflammation is usually linked to brain atrophy (at least among Westerners). For whatever reason, the Tsimane people’s brains don’t appear to be all that affected by high levels of bodily inflammation.

This is only a theory, but study authors speculate these differences may be tied to the type of inflammation. In the West, bodily inflammation is usually synonymous with conditions like obesity and other metabolic issues, whereas Tsimane inflammation is linked more to respiratory, gastrointestinal, and parasitic infections (no doubt due to inadequate access to modern medical care).

“Our sedentary lifestyle and diet rich in sugars and fats may be accelerating the loss of brain tissue with age and making us more vulnerable to diseases such as Alzheimer’s,” explains study author Hillard Kaplan, a professor of health economics and anthropology at Chapman University who has studied the Tsimane for nearly two decades. “The Tsimane can serve as a baseline for healthy brain aging.”

This isn’t the first study to pick out the Tsimane as a great health example. Another project from 2017 found tribe members “have extraordinarily healthy hearts in older age.”

“This study demonstrates that the Tsimane stands out not only in terms of heart health, but brain health as well,” Kaplan concludes. “The findings suggest ample opportunities for interventions to improve brain health, even in populations with high levels of inflammation.”

What can you learn from this tribe to help your brain

Well before you pack and move to the wilds of the Bolivian Amazon, there are a few simple diet changes you can make to at least get on the right path. Plus, though we have all the technology and entertainment at our fingertips, being outside and moving our bodies in nature can benefit us more than we think.

The full study can be found here, published in the Journal of Gerontology: Biological Sciences.