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A lot of discussion is constantly had about what is the healthiest diet; low fat or low carb. An interesting study was published in the Lancet recently where anthropologists teamed with cardiologists to study cardiac health of Amazon’s Tsimane. The Tsimane are Bolivian. They live off and around the Maniqui River located in the Amazon rainforest. There are about 16,000 of them. They hunt and gather, fish and farm. The Tsimane provide a unique window into pre-industrial lifestyle… Before the incidence of coronary artery disease.

Researchers said the study came from the need to comprehend coronary artery disease. Image credit: Klug Photos.

Researchers said the study came from the need to comprehend coronary artery disease. Image credit: Klug Photos.

In the last 15 years, we have learned a lot about the lives of the Tsimane. There is a division of labor. The men hunt or fish, and row or rather pole their canoes to sell food for about 7 hours a day. The women gather, farm in contrast. Wild boar, tapir, and capybara make up for 17% of their diet. Freshwater fish like catfish and piranhas count for 7% of it. They also eat fruits, nuts, rice, maize, manioc root, and plantains.

Members of this community average walking 17,000 steps a day, or about 8 miles. They eat a high carbohydrate diet. 72% of their diet come from starches such as rice and corn, plantains and roots. The other 28% is split evening between fats and protein. Americans and Tsimane consume the same percentage of protein, but the indigenous group consumes far less saturated fat. Interestingly, they have a high infectious disease rate, so their population’s immune systems are chronically inflamed.

The study looked at the blood work and imaging of 705 Tsimane between 40 and 94 years old to look at cardiac disease like atherosclerosis. The authors created a scoring system where 0 indicated 0 disease detected and 1-99 indicated low level of disease. A number more than 400 meant high levels of coronary artery disease.

 

85% of the population had a score of 0! And 3% hd a score >99! In a subset of Tsimane older than 75 years, only 8% had a number greater than 99! One person, yes, one had a number greater than 399. In total the Tsimane had scores less than the 20th percentile of US or European people and developed evidence of cardiac artery disease 25 year later than the rest of the world. They even exhibited less atherosclerosis than Japanese women, who were once concerned the population with the the least cardiac disease.

This is a beautiful real life medical anthropology study which reaffirms that eating a healthy diet, not smoking and being active lifelong, is associated with the lowest risk of having furring up of blood vessels. One interesting question from Hillard Kaplan, from the University of New Mexico in Albuquerque and the study’s co-author is the mantra in popular science of fats vs carbohydrates on the health of the heart. It seems like low carbs doesn’t affect the incidence of coronary artery disease. I think the jury is still out, though.

One thing is certain however, the Tsimane are in constant motion every day compared to us. They are more active despite their diets than we are. Looking prospectively at the Tsimane we can see how modernity will change their health as now some Tsimane are using motorized canoes. Maybe their hearts will look like ours?

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