Life Without Modern Comforts: The Tsimane Way
Every year, anthropologists, neuroscientists, and medical researchers gather in this region to study how the Tsimane age. Their research, led by Hillard Kaplan, professor of anthropology and health economics at Chapman University, has become crucial in understanding how modern life could be accelerating brain aging worldwide.
In the remote lowlands of the Amazon Basin, a small Indigenous group called the Tsimane lives far removed from the fast-paced, industrialized world. Villages like Las Maras, located in northern Bolivia, have no running water and little to no electricity. The Tsimane rely on slash-and-burn agriculture, foraging, and hunting to sustain their families. Their lives are physically demanding but closely connected to nature, offering a glimpse into a lifestyle free from the comforts — and perhaps the hidden dangers — of modern living.
The Science Behind Brain Aging
Human brains naturally shrink as we grow older. This shrinkage starts around age 40 and is associated with cognitive decline, memory loss, and increased risk of neurodegenerative diseases like dementia and Alzheimer’s. The World Health Organization (WHO) reports that over 55 million people worldwide suffer from these conditions.
However, most brain aging research focuses on people living in industrialized societies — mainly white populations in the U.S. and Europe. This creates a significant research gap when it comes to Indigenous and non-industrialized groups. Kaplan and his team set out to challenge this bias.
A Long-Term Study in the Amazon
Between 2014 and 2019, Kaplan’s team visited over 100 Tsimane villages, offering voluntary medical exams, brain imaging, and health care services. About 90% of the villagers participated, motivated by both curiosity and the promise of much-needed medical attention. Collaborating closely with the Tsimane people, Kaplan’s work collected critical data on their cardiovascular and brain health.
The study also included the neighboring Moseten people, who live more modernized lives but still rely on farming and small-scale trade. This allowed researchers to compare two similar groups with varying degrees of exposure to industrialized life.
What the Data Reveals: Slower Brain Aging in the Tsimane
After years of research involving over 1,100 participants, Kaplan’s team found that Tsimane brains shrink significantly slower than brains in industrialized populations. Here’s what the data showed:
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Tsimane brains lose about 2.3% of their volume per decade after age 40.
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Moseten brains lose about 2.8% per decade.
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Industrialized populations (U.S. and Europe) show an average shrinkage of 3.5% per decade.
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Among those aged 70 and older, the difference nearly doubled.
Even more surprising, brain volume among the Tsimane increased with higher BMI (Body Mass Index) and cholesterol levels, which is the opposite of what is typically observed in the West. In industrialized societies, high BMI and cholesterol are linked to cardiovascular disease and brain shrinkage, but among the Tsimane, it may provide extra energy essential for their physically demanding lifestyles.
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The “Embarrassment of Riches” Hypothesis
Kaplan describes this paradox as the “Embarrassment of Riches” hypothesis. In simple terms: too much food and too little activity lead to negative health effects. In modern societies, we consume excessive calories without expending enough energy. In contrast, the Tsimane maintain higher levels of physical activity — walking an average of 17,000 steps daily — which seems to balance their energy input and output, protecting both heart and brain health.
Researchers now suspect that this balance may help slow brain aging and prevent neurodegenerative conditions common in industrialized populations.
Historical Clues from Other Indigenous Groups
Kaplan’s interest in the connection between lifestyle and aging began decades ago with the Mashiguenga, another Indigenous Amazonian group. While working there, he found little evidence of heart disease, hypertension, or diabetes, even among the elderly.
This consistent pattern across different Indigenous groups suggests that modern chronic diseases may not be inevitable, but largely influenced by lifestyle factors like diet, activity, and environment.
Modern Society and the Risk of Accelerated Brain Aging
In contrast, diseases like Alzheimer’s, heart disease, diabetes, and cancer accounted for over 56% of deaths in the U.S. in 2019 alone. Industrialized societies suffer from what Kaplan calls “the overshoot”—too many calories, too little physical activity, and too much convenience.
Other studies show that exercise lowers dementia risk by at least 30%, likely due to reduced inflammation and improved synaptic health. Yet, most people in the modern world struggle to maintain an active lifestyle.
The Role of Genetics and Social Well-being
While Kaplan’s findings highlight lifestyle as a major factor, genetics also likely plays a role. Research on “superagers” — people over 80 with unusually youthful brains — shows that not all cognitive health can be attributed solely to exercise and activity. Factors like social engagement, mental stimulation, and emotional well-being also influence brain aging
In fact, studies indicate that happy, social, and mentally active people may maintain sharper cognitive function into old age, regardless of physical health.
The Tsimane at a Crossroads
Modernization is slowly reaching the Tsimane through cheaper transportation and easier access to markets and healthcare. While these changes bring undeniable benefits, researchers are concerned that the Tsimane may soon face the same health challenges seen in the industrialized world.
Will their brains continue to age slowly, or will their shift towards modern living accelerate cognitive decline? Kaplan and his colleagues intend to keep studying this delicate balance.
Final Thoughts
The Tsimane offer more than just data; they provide a living example of how balancing energy intake with physical effort may protect not just the heart, but also the brain aging. Kaplan believes understanding this balance could improve brain health globally — especially in societies plagued by sedentary lifestyles and poor diets.
As modern science digs deeper, we may find that the key to healthy aging isn’t hidden in high-tech solutions, but in returning to some of the basics our ancestors practiced daily.
Read more: Will Stimulating My Brain as I Age Keep It Sharp?
FAQ Section
1. What causes brain aging?
Brain aging is primarily caused by natural biological processes, including loss of neurons and brain shrinkage, starting around age 40. However, modern factors like poor diet, lack of physical activity, chronic inflammation, and stress may accelerate brain aging and cognitive decline.
2. Why do the Tsimane people have healthier brains?
The Tsimane maintain physically active lifestyles, eat natural foods, and have limited exposure to industrialized living. Their constant physical activity and balanced energy intake may help reduce inflammation and protect brain volume as they age.
3. Can exercise slow down brain aging?
Yes, regular physical activity is proven to slow brain aging. Studies show that exercise reduces the risk of dementia by up to 30%, lowers inflammation, and improves brain plasticity, helping to maintain cognitive function longer.
4. Is brain shrinkage normal with age?
Yes, brain shrinkage is a normal part of aging. However, the rate of shrinkage varies. Industrialized populations tend to experience faster brain shrinkage due to sedentary lifestyles, poor diets, and other preventable health risks.
5. How can I protect my brain aging too fast?
To protect your brain, prioritize daily physical activity, a balanced diet, stress management, social engagement, and mental stimulation. Adopting healthier habits, like those seen among the Tsimane, can significantly reduce the risk of cognitive decline.
