Coronary Artery Calcium CT Scan showing calcified plaque in the LAD widowmaker artery

Actually, it would be premature to anticipate people copying the lifestyle of a remote tribe living in the Bolivian jungle, but the news has been abuzz with the report that the Tsimane people have an incredibly low rate of heart disease compared to Western populations. The Tsimane live in villages of about 60 to 200 people. They often live relatively long — the most common age at death is 70.

In data published in the journal Lancet and announced at the American College of Cardiology, the results of coronary artery calcium scoring (CACS) using CT imaging in 705 adults living in remote villages between 2014 and 2015 were reported. The non-invasive heart check via CACS is the best predictor of heart disease and a direct measure of atherosclerosis. These residents of primitive villages were transported to a medical center for the evaluation.

Based on their CACS, almost nine in 10 of the Tsimane people (85%) had no risk of heart disease because of a CACS of zero, 13% had low risk and only 3% had moderate or high risk. These findings also continued into old age, where almost two-thirds (65%) of those aged over 75 years old had almost no risk and only 8% had moderate or high risk. These results are the lowest reported levels of vascular aging of any population recorded to date.

By comparison, a US study of 6814 people (aged 45 to 84) found that only 14% of Americans had a CT scan that suggested no risk of heart disease and half (50%) had a moderate or high risk — a 500% higher prevalence than in the Tsimane population. In the Tsimane population, heart rate, blood pressure, cholesterol, and blood glucose were also low, potentially as a result of their lifestyle.

The Tsimane spend only 10% of their daytime inactive. They live a lifestyle including hunting, gathering, fishing and farming, where men spend an average of 6–7 hours of their day being physically active and women spend 4–6 hours. This is far less than the average 50% of time spend in sedentary activities in Western societies.

The diet of the Tsimane was composed largely of complex carbohydrates (72%) high in fiber such as rice, plantain, manioc, corn, nuts and fruits. Protein constituted only 14% of their diet largely from animal meat caught in the wilds. Their diet is very low in fat with only 14% of their calories being fat calories. This is as low as the traditional Okinawan population known for longevity as a Blue Zone and in the range of the famous heart disease prevention and reversal studies of Dean Ornish, MD and Caldwell Esselstyn, MD. The diet was also very low in saturated fat, averaging 11 grams, and had no measurable trans fats. By contrast, the typical U.S. adult diets have more fat — about 16 percent protein, 33 percent fat and 51 percent carbohydrate, according to Centers for Disease Control statistics. Smoking was rare in the population.

The graphs below show the CACS in women and then men up to age 85 in the Tsimane population in aqua compared to a range of populations in the United States in the MESA trial. It is striking how little coronary calcification was found even at advanced ages compared to the comparable age groups in Western populations.

This chart compares levels of plaque in coronary arteries in the women and men of various cultures. The Tsimane are lowest. The lines reflect the 75th percentile in each group. Source: The Lancet

While the lifestyle and health of the Tsimane people may soon change with the availability of transportation and exposure to Western conveniences, the lessons for longevity and freedom from heart disease are clear. Decisions not to smoke and to pursue an active lifestyle of exercise, walking, standing and even fidgeting have all been shown to favor heart health and are borne out by the CT findings in the Tsimane.

In an era when the role of dietary fats, “healthy fats”, and saturated fats have opposing schools and has led to public confusion, the remarkably low fat diet of the Tsimane is a pattern supported once again for youthful heart arteries. Very few people in Western societies follow a diet consisting of 14% or less of calories from fat but the relationship with the healthy heart arteries of the Tsimane argue for largely whole food, plant based diets with very little or no butter, full fat dairy, animal meats, oils, or eggs. The trend in California of blending butter and coconut oil in coffee to create a very high fat drink, known as Bulletproof Coffee, has clearly not reached the jungles of Bolivia. Their exceptional heart health speaks volumes about not following that trend or high animal food diets in general.