Mummies Behind the Scenes at the National Museum of Natural History This mummy looks rightfully worried about his arteries. (Jahi Chikwendiu/The Washington Post.)

Heart disease is often thought to be a malady of the modern era, the product of lifestyles heavy on eating and light on exercise.

That includes conditions like atherosclerosis, when fat and cholesterol build-up along artery walls, making it difficult for blood to pass through the body to the heart and limbs.

New research, presented Sunday night at a meeting of the American College of Cardiology, suggests the exact opposite: That heart disease is a malady with a history that stretches back over 4,000 years. How, exactly, did they figure this out? By putting mummies through CT scan machines, of course.

A team of more than a dozen researchers—some here in the United States and others abroad in Egypt, Peru and the United Kingdom—were able to do full-body CT scans of 137 mummies. The sample population included 76 Egyptians, 51 Peruvians and 10 other mummies from excavation sites scattered across South America and Alaska.

These very ancient patients were treated to some very modern technology, all undergoing CT scans from equipment manufactured by companies like Siemens and Phillips. Seven experienced cardiovascular imaging specialists would then review the scans for signs of hardened arteries—just as they would for a patient still alive.

Here's what one of those scans looks like, with a few notations from doctors on where the arteries are hardening:

They saw that about one-third of the population—47 mummies—showed signs of "probable or definite" hardened arteries. Only 4 percent of the sample, however, had the condition in their coronary arteries, where it would cause a heart attack.

The condition showed up in at least some of the mummies found in all four areas represented (Egypt, Alaska, Peru and elsewhere in South America).

The condition tended to be more prevalent among mummies who died older, over the age of 30, than the younger bodies studied.

As to why this condition would show up in ancient populations—one typically associated with consuming a high level of saturated fats and smoking—the researchers have a few ideas.

One has to do with smoke inhalation: While cigarettes did not yet exist, each of the four cultures did rely on cooking to prepare their foods.

"Cooking was often done outdoors by Peruvians but indoors over a fire among the Ancestral Puebloans and, to a lesser extent, the ancient Egyptians," they write in the journal The Lancet. "The Unangans in particular, were exposed to smoke within their living quarters. Entry into a barabara was through a hole in the roof via a slated timber, through which the inhabitant climbed.

"Although cigarette smoking was not part of these four ancient populations, the need for fire and thus smoke inhalation could have played a part in the development of atherosclerosis."

The researchers also posit that chronic infections—at the time, a major cause of death—could have also played a role in inflaming a case of atherosclerosis.

So, there you have it: Even without fatty foods, some mummies seem to have managed to develop risks for heart disease too.