Rainforest regime could be key to a healthy heart

Michael Doyle
March 19, 2017

The Tsimane people of Bolivia lead an active life of subsistence farming and foraging for food in the Amazon rainforest, said study author Dr. Gregory Thomas.

"We found that based on their lifestyle, 85 percent of this population can live their whole life without any heart artery atherosclerosis [hardening]", Thomas said.

"There may not be many old Tsimane men with heart disease but that's probably because only the fittest and healthiest Tsimane survive to old age", said Gavin Sandercock, a cardiology expert from the University of Essex.

Coronary atherosclerosis, the gradual hardening and "furring up" of the arteries, can have serious consequences including heart attacks and strokes. "There's a tendency to blame your genes for heart problems and what this study shows us is that you can't blame your parents, just your lifestyle".

Similar scans of almost 7,000 Americans in a previous study showed that only 14 per cent had no risk of heart disease, with half at moderate-to-high risk - a five-fold greater prevalence rate than that seen in the Tsimane population.

And the difference was so stark they estimated that an average 80-year Tsimane has the typical cardiovascular health of an average American in their mid-50s.

The researchers say their findings don't suggest that all people need to adopt a hunter-gather lifestyle. Image credit: Klug Photos."Conventional coronary disease risk factors might potentially explain at least 90 percent of the attributable risk of coronary artery disease", the study reads.

"Our study shows that the Tsimane indigenous South Americans have the lowest prevalence of coronary atherosclerosis of any population yet studied", said Hillard Kaplan, the study's senior anthropology author from the University of New Mexico.

"The closest were Japanese women, but it's still a different ballpark altogether".

But while the research on the Tsimane and other groups living a "pre-modern" lifestyle suggests that heart disease may be a outcome of modernity, at least some evidence, developed by some of the same researchers, points in a different direction.

Prof Naveed Sattar, from the University of Glasgow, said: "This is a lovely real life study which reaffirms all we understand about preventing heart disease".

The Tsimane people dwell in thatched huts in a remote corner of Bolivian jungle, and at dinner, the main meal sometimes consists of monkey. Their home is located in the Bolivian lowlands, and it took the team of scientists much trouble to get there.

Wild boar, tapir, and capybara make up for 17 percent of their diet, and freshwater fish like catfish and piranhas count for 7 percent of it.

Americans and Tsimane consume the same percentage of protein, but the indigenous group consumes far less saturated fat. They eat a diet rich in vegetables, grains, lean meat and fish and - perhaps most importantly - they spend most of their day walking. Scientists appear to be more impressed with the level of exercise that the Tsimane put in. Riding a bicycle to work and taking the stairs can do a lot for the cardiovascular system.

It has no symptoms at first, but can be prevented through a healthy lifestyle.

Gurven says that modern world keeps people alive, but urbanization and the specialization of the labor force could translate to new risk factors for coronary disease. In addition, the Tsimane people in the study had blood tests to measure cholesterol levels and inflammation. Professor Naveed Sattar from the University of Glasgow was reached by the BBC for comments too.

Other reports by Ligue1talk

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