Cardiologist Gregory Thomas had some doubts.

Perusing the plaque of a millennia-old mummy in the Egyptian Museum in Cairo, he read that Menephtah had not died of trauma or infection, but of heart disease—a hardening of the arteries called atherosclerosis. Thomas was skeptical; ancient humans had none of the known risk factors for this condition, which today include inactivity, smoking, and poor diet.

“I didn’t accept that. I thought, how could he have atherosclerosis? He was living a life walking along the Nile. There were no cars, there were no cigarettes. He had a fully organic diet, probably not much red meat,” Thomas said.

Discovering, to his surprise, that the museum had a CT scanner, Thomas and an international team of scientists decided to test the plaque’s assertion. CT scans are used to diagnose diseases such as atherosclerosis in living patients. “We were using a 21^st-century instrument, looking across 3000 years of health and disease,” said Randall Thompson, first author of the study published in June’s issue of Global Heart.

Thompson found CT scanning a mummy is somewhat more complicated than scanning a living patient. “No one’s written a textbook on how to read a mummy CT scan,” he said. However, the scientists managed to successfully detect atherosclerosis in over one-third of the ancient Egyptians tested. This turned the researchers’ sites farther afield—to North America, Peru, and even the Austrian Alps, detecting atherosclerosis in populations that ranged both in time and geography.

The authors speculate that there may be risk factors common to these diverse populations, despite their more active lifestyles and obligatory Paleo diets. Inhaling smoke while cooking might confer similar risk as breathing in tobacco smoke, and the chronic infections our ancestors suffered could potentially have caused the inflammation that has been linked to atherosclerosis.

Thomas and Thompson hope their findings will alleviate some of the guilt felt by patients with atherosclerosis today. Thomas tells them heart disease is “part of being human. But now, there are a lot of ways we know to slow down atherosclerosis.”