As Americans race to unlock the secret to anti-aging, the answer could be tucked away in the depths of the Amazon rain forest.
The Tsimané people boast the “healthiest hearts on the planet” and brains that age far more slowly than their Western counterparts, with just 1% of the population showing signs of dementia.
Research suggests their pre-industrial lifestyle, marked by a unique balance of food consumption and physical activity, may hold the key.
“This ideal set of conditions for disease prevention prompts us to consider whether our industrialized lifestyles increase our risk of disease,” said Dr. Andrei Irimia, an associate professor at the University of Southern California’s Leonard Davis School of Gerontology who studies the tribe.
A community in the heart of the jungle
There are an estimated 17,000 Tsimané living deep in the lowland Bolivian jungle. This isolated indigenous community stays physically active throughout their lives, fishing, hunting, farming and foraging from the tropical forest.
They live near the Mosetén people, who also reside in rural villages and rely on subsistence agriculture for their livelihoods.
In 2022, an international research team discovered that among older Tsimané and Mosetén, only about 1% suffer from dementia. By comparison, 11% of Americans aged 65 and older have the memory-robbing disease, according to the Alzheimer’s Association.
“Something about the pre-industrial subsistence lifestyle appears to protect older Tsimané and Mosetén from dementia,” said Margaret Gatz, the lead study author and professor at the USC Dornsife College of Letters, Arts and Sciences.
Previous studies have shown that both the Tsimané and Mosetén experience significantly less brain atrophy than industrialized populations in the US and Europe. Brain atrophy is strongly linked to cognitive decline, functional impairment and dementia.
But here’s the twist: The Tsimané and Mosetén, while both living traditional lifestyles, differ significantly in terms of modern exposure. Though they share similar languages and history, the Mosetén have more access to modern technology, medicine and education.
While the Mosetén are healthier than most Westerners, they don’t quite match the Tsimané’s extraordinary health.
In fact, researchers have found that among the Tsimané, a higher body mass index (BMI) and slightly elevated levels of “bad cholesterol” are associated with larger brain volumes for their age.
This could be due to the Tsimané being generally more muscular than individuals in industrialized countries with similar BMIs — likely a result of their active, physically demanding lifestyle.
Even more surprising is the Tsimané’s high levels of inflammation, which is typically linked to brain atrophy in Western populations. However, studies suggest that high inflammation doesn’t have the same impact on their brains.
The Tsimané community first captured the attention of scientists when a 2017 study revealed their extraordinary heart health in older age.
Researchers discovered that the Tsimané have the lowest prevalence of coronary atherosclerosis — a condition marked by fatty deposits inside the arteries — of any known population. Additionally, they have remarkably few cardiovascular disease risk factors.
Scientists believe that the Tsimané’s low cardiovascular risks may outweigh the inflammation caused by infections, raising new questions about the true causes of dementia. While inflammation in Westerners is often linked to obesity and metabolic issues, in the Tsimane, it’s primarily driven by respiratory, gastrointestinal, and parasitic infections.
“This study demonstrates that the Tsimané stand out not only in terms of heart health but brain health as well,” said Hillard Kaplan, a professor at Chapman University who has studied the community for nearly two decades. “The findings suggest ample opportunities for interventions to improve brain health, even in populations with high levels of inflammation.”
Diet and activity: a vital balance
While people in industrialized nations enjoy modern healthcare, we’ve grown accustomed to exercising less and eating more — especially diets rich in sugars and fats.
By contrast, the Tsimané have little or no access to healthcare but remain extremely physically active and consume a high-fiber diet full of vegetables, fish, and lean meats.
“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,” Kaplan said.
When CNN’s chief medical correspondent, Dr. Sanjay Gupta, visited the Tsimané in the Amazon rainforest, he was surprised to find that most of their calories come from carbohydrates.
The Tsimané’s diet is straightforward and unprocessed, free from added sugars and salts. Plantains, cassava, rice, and corn make up nearly 70% of their food intake, with 15% derived from fat and another 15% from protein.
Gupta noted that this carb-heavy approach is born out of necessity, as farmed food offers more predictability, especially during lean hunting seasons. The diet provides twice the fiber of the typical American diet and is rich in micronutrients like selenium, potassium, and magnesium.
When Gupta visited the tribe, he also discovered that intermittent fasting was part of the Tsimané culture — not a trendy practice, but one born out of food scarcity. Experts say this is common in pre-industrialized societies.
“The lives of our pre-industrial ancestors were punctured by limited food availability,” said Irimia. “Humans historically spent a lot of time exercising out of necessity to find food, and [the Tsimane’s] brain aging profiles reflected this lifestyle.”
Gupta observed that nearly all of the Tsimané’s waking hours involve standing or walking, with hunting and foraging lasting all day. On average, they take about 17,000 steps daily, while also getting ample rest at night.
Researchers suggest that the Tsimané’s unique balance of physical exertion and food availability could hold the key to healthy aging.
They point out that in societies with abundant food and little physical activity, people often struggle between what they know is best for their health and the cravings that evolved over time.
“During our evolutionary past, more food and less calories spent in getting it resulted in improved health, well-being and ultimately higher reproductive success or Darwinian fitness,” Kaplan said.
“This evolutionary history selected for psychological and physiological traits that made us desirous of extra food and less physical work, and with industrialization, those traits lead us to overshoot the mark.”
According to Irimia, the ideal scenario for brain health and disease risk is the “sweet spot” — a place where the brain is provided with neither too little nor too much food and nutrients, while also getting a healthy dose of exercise.
With the global population aging, along with rising risk factors, researchers predict the number of people with dementia will triple to more than 152 million worldwide by 2050.
“We’re in a race for solutions to the growing prevalence of Alzheimer’s disease and related dementias,” Kaplan said. “Looking at these diverse populations augments and accelerates our understanding of these diseases and generate new insights.”
