heart disease prevention Tsimane Bolivian jungle

Heart Disease Prevention Secret Discovered In Bolivian Jungle?

In a remote corner of the Bolivian jungle, the Tsimane people live in thatched huts, but what’s interesting about these people is that they have the lowest rates of heart disease ever measured.

So why is that? Many people believe it’s their secret diet. The Tsimane people eat monkeys and piranhas, and at other times it might be a hog-nosed coon or a peccary, which is a type of wild pig. From their local rivers they catch catfish, and for sides the Tsimane people gather fruit and nuts, or eat produce from their own farm plots, like corn, plantains, and rice.

The Washington Post reported that, according to a study published in the Lancet, the Tsimane people have the lowest reported levels of coronary artery disease of any population recorded to date.

With the United States and parts of Europe having heart disease as their leading cause of death, this is interesting news indeed, and certainly arouses curiosity. The question remains: How do they do it?

Seven hundred and five Tsimane traveled for two days by road and boat to attend a clinic where scientists examined them for heart disease. Each person underwent sophisticated x-ray scans of their coronary arteries to determine the amount of calcium plaque, which is a measure of heart disease. The results were that the Tsimane measured healthier than any other people studied, and according to researchers this includes groups from Europe, the United States, Japan, and Korea.

Randall Thompson was one of the authors of the study, and is a cardiologist at Saint Luke’s Mid-America Heart Institute in Kansas City.

“If you think of the calcium plaque as a reasonable measure of arterial age, their arteries are 28 to 30 years younger than ours. Obviously the Tsimane are achieving something that we are not.”

The results of this study are not really surprising, because many previous studies of remote groups have raised doubts about the modern lifestyle. Analysis in 1984 found that members of the Luo tribe in Kenya who migrated to Nairobi had higher blood pressure than those who remained in the villages. Another study from the 1960s showed that, despite a diet high in milk and meat, the Maasai of East Africa had very low levels of blood cholesterol. And in Greenland, studies have shown that the Inuit have low levels of blood cholesterol.

Further, researchers said electrocardiograms of Kung Bushmen “confirmed the impression that hypertension and ischaemic heart disease, two of the most important heart ailments in Western Society, do not occur in the Bushman.”

It was in 1999 when Michael Gurven first visited the area and began studying the Tsimane people. Gurven was an anthropologist at the University of California in Santa Barbara. A few years later he again visited the area and, together with colleagues, developed a project to study the lives and health of the Tsimane people. The research carried out on the Tsimane was slightly different to other research projects inasmuch as the scientists used computer-enhanced x-ray scans (CT) to determine how much plaque was clogging the arteries around the heart.

Matthew Budoff is a UCLA cardiologist and expert in coronary calcium.

“These calcium scores are the best predictors of heart disease. It’s a direct measure of atherosclerosis. It’s literally measuring the disease in the artery.”

When comparing the levels of plaque in coronary arteries of men and women of various cultures, the Tsimane are the lowest. Heart disease is very prevalent in United States, and this research has inspired further research efforts: it seems that the causes of heart disease are varied, ranging from diabetes, smoking and obesity, through to stress, diet and lack of exercise.

The New England Journal of Medicine recently reported on an analysis of studies of 55,685 people, and the results were that the people half as likely to experience heart disease were those who had a favorable lifestyle; meaning people who do not smoke, are not obese, have a balanced diet, and who exercise at least once a week.

However, the importance of each of the above lifestyle factors is often fiercely debated, and the definition of a “healthy diet” almost always raises scientific disagreement.

Dennis Bier is editor of the American Journal of Clinical Nutrition and a professor at Baylor College of Medicine.

“There’s a consistency of data throughout the world that people who have low cholesterol, keep active, don’t smoke, avoid obesity, and maintain their blood pressure live a longer life.”

However, he did warn that it’s difficult to know how these factors contribute to health.

“People in these other societies often provide us clues to these health questions, but determining the reasons for their unique metabolism is frequently not so easy to do.”

The Tsimane researchers also acknowledged that the causes of Tsimane health are not easy to distinguish from one another, but they did note the differences between the diets of industrialized societies and the Tsimane diet.

According to statistics from the Centers for Disease Control, 72 per cent of the Tsimane diet is carbohydrate, 14 per cent is protein, and 14 per cent is fat; whereas a typical adult’s diet in the United States has more fat – 33 percent fat, 51 percent carbohydrate, and 16 percent protein.

“Importantly, their carbohydrates are high in fiber and very low in saturated fat and simple sugars, which might further explain our study findings.”

What’s really important to note is that the Tsimane people exercise a great deal. An average hunt may cover more than 10 miles of tracking and last more than eight hours. They use metal axes and scythes to cut their farm plots out of the jungle, and this has to be done every growing season because of the thinness of the soil. It is estimated that less than 10 per cent of their daylight hours consist of sedentary activity, whereas in the industrial world more than 54 per cent of waking hours are counted as sedentary.

The Tsimane people live in villages of between 60 and 200 people, and they live relatively long lives. Benjamin Trumble was one of the anthropologists on the project, living among the Tsimane on and off for two years.

“People often think that life in these places is nasty, brutish and short. But that just isn’t the case.”

Of course, there are many reasons why the Tsimane lifestyle is unlikely to be emulated. Yes, they may be free of heart disease, and they have lower levels of blood pressure, cholesterol, and blood sugar, but they do suffer other health problems. They lack clean water, and about two thirds of adults have parasitic worms. And their diet? By Western standards it’s not really considered tasty. Apparently, the Capuchins taste like pork, but the howler monkeys don’t taste very good at all!

Time magazine reported that the lifestyle of the Tsimane people plays a major role in the risk for heart disease. Their diet is typically low in fat, and people rarely smoke.

By contrast, smoking rates in the United States are much higher, with about 50 per cent of adults currently smoking, and many people are either sedentary or inactive most of the day. The consumption of processed food also plays an important part in Western diets. But the good news is that researchers say their findings are not suggesting that people should adopt a hunter gatherer lifestyle.

“The Tsimane are people just like us in many respects, but live under very different conditions. We don’t want to look to the Tsimane and say this is how all people should live. It’s also a very difficult life, and they’ve benefited from modern changes. But there are real lessons.”

What they are saying, though, is that some heart disease risk factors could be avoided if some elements of the Tsimane lifestyle were incorporated into people’s lifestyle: elements like not smoking, being more active, and being more concerned with a healthy diet.

[Featured Image by Michael Gurven/AP Images]