Heart disease and strokes have been rare throughout human history.  Why, then, do so many of us today die from heart-related illnesses?  The University of Southern California set out to answer that question and they found an answer in the Tsimane tribe of the Amazon.

With only limited access to medical services, half of documented deaths among the Tsimane are due to infectious or parasitic disease. About two-thirds of the population has intestinal worms, the researchers found.

“We looked at a lot of populations in both developed and developing countries, in urban and rural settings, but none live in the relatively isolated and infected conditions of the Tsimane,” the researchers write.

Chronic inflammation, which may lead to damage of the arteries, is prevalent among the Tsimane. According to the study, the Tsimane also have unusually high levels of C-reactive protein, increasingly used in clinical settings to evaluate risk for cardiovascular disease.

Yet, despite these risk factors for heart attacks, the researchers found that the high levels of C-reactive protein were unrelated to risk of peripheral arterial disease (the hardening of plaque in the arteries).

In fact, peripheral arterial disease “increases with age in every investigated population except the Tsimane,” according to the study. Among the Tsimane, not a single adult showed evidence for peripheral arterial disease (measured using the ankle-brachial blood pressure index).

The most interesting part of the Tsimane study is how infant and childhood mortality rates remained the same while the elderly population is living longer.

Since 2002, six rounds of medical checkups on over 3,000 Tsimane have uncovered a wealth of information concerning health status and disease epidemiology. Human specimen and medical data show that the Tsimane suffer from very high rates of infectious disease and parasitosis. Over three fourths of all Tsimane are infected with at least one species of intestinal parasite. Over half are anemic, and over four-fifths present some complaint or symptom of morbidity during medical examinations.

Is it possible parasite infections might have some sort of regenerative
healing properties for the heart and arteries? 

Is something expressed
by the body to fight off these parasites that, in some way, then provides
protection for the heart?

The wonderment of the body is how quickly it can move to ward off external invasions and fight internal dissension — and it makes sense on a logical level that the body chooses to heal on many fronts instead of just one — perhaps in the same way we involuntarily blink and twitch our muscles to stay in motion at all times. We cannot wait to learn more about the USC Tsimane heart study.