The study presented in March at the American College of Cardiology conference was authored by the Horus Group – a team of experts in cardiology, radiology, infectious disease, pollution research and anthropology that includes Renown Institute for Heart & Vascular Health cardiologist Dr. Christopher Rowan.
In researching the Tsimane people, study authors discovered this indigenous South American group has some of the healthiest hearts in the world. Researchers measured the weight, age, heart rate, blood pressure, cholesterol, blood glucose and inflammation of 705 Tsimane people ages 40 to 94. They also took computerized tomography (CT) scans of their hearts. Then, the data was used to evaluate their risk of heart disease.
Eighty-five percent of Tsimane people had no risk of heart disease and only 3 percent had moderate or high risk. In the U.S., the risk is nearly five times higher with just 14 percent of Americans showing no risk and half showing moderate or high risk. Another incredible example from the study, an 80-year-old from the Tsimane group had the same vascular age as an American in their mid-50s.
With these new statistics, the Tsimane lifestyle is now the embodiment of heart health. Living a subsistence lifestyle that involves hunting, gathering, fishing and farming, Tsimane men spend six to seven hours of their day being physically active and women spend four to six hours each day. This translates to just 10 percent of inactivity each day compared to industrialized populations where the sedentary rate is 54 percent each day.
Diet is another key factor. The Tsimane diet is largely carbohydrate-based – making up 72 percent of their diet – but the majority of their carbohydrates are non-processed such as rice, plantains, maize, nuts and fruits. Protein from animal meat makes up another 14 percent and fat is just 14 percent of their diet each day.
“This study is a prime example of nature versus nurture when it comes to heart health,” said Dr. Christopher Rowan, cardiologist with Renown Institute for Heart & Vascular Health and study author. “Over the years, many have suggested genetics are responsible for the increase in heart disease. These results counter that notion – showing that lifestyle may play an even bigger role in heart health than originally thought.”
Some scientists are saying the results are so significant they may lead to contemporary diet and lifestyle being classified as a new risk factor for heart disease. Currently, the main risk factors include age, smoking, high cholesterol, high blood pressure, physical inactivity, obesity and diabetes.
Researchers are also studying cancer rates in the Tsimane but have seen little evidence of the disease so far. Here in the U.S., cancer and heart disease are the leading causes of death and most cases are strongly tied to poor diet and inactivity.