Major physical changes occurred in the human heart as people shifted from hunting and foraging to farming and modern life. As a result, human hearts are now less “apelike” and better suited to endurance types of activity. But that also means those who lead sedentary lives are at greater risk for heart disease.

Those are the main conclusions from a unique study led by Aaron Baggish, Harvard Medical School associate professor of medicine and director of the Massachusetts General Hospital Cardiovascular Performance Program. Baggish and his collaborators examined how ape hearts differ from those of humans, why those differences exist and what that means for human health.

The researchers measured and compared heart function in apes and four groups of humans, ranging from sedentary to elite runners and including indigenous subsistence farmers. Their research is presented in the Sept. 2019 issue of PNAS.

Baggish’s collaborators on this paper include Daniel Lieberman, Department of Human Evolutionary Biology, Harvard University, and Robert E. Shave, School of Health and Exercise Sciences, University of British Columbia

Chimpanzees are humans’ closest known relatives, based on genetics and evolutionary studies. There are, of course, some stark differences between the species. For example, in terms of exertion, chimpanzees mainly engage in short bursts of activity, such as climbing and fighting, which puts intense pressure on the heart but only for a limited time.

In contrast, it’s believed that up until the industrial revolution, humans were active for longer periods of time in order to hunt and farm. Survival of pre-industrial humans, it is thought, depended on moderate-intensity endurance activity (e.g., hunting and gathering and then farming).

Read more at Harvard