Long thought to be a modern disease related to contemporary lifestyles, atherosclerosis was common among ancient people as well, a new study found.
Whole body CT scans of 137 mummies from four different ancient populations revealed heart and vascular calcifications consistent with atherosclerosis, reported Dr. Randall Thompson of St. Luke's Mid America Heart Institute in Kansas City, Mo., and colleagues.
"We were most surprised to find atherosclerosis among hunter-gatherers, whose varied diet and active lifestyle would presumably place them at low risk," he told MedPage Today.
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The findings were reported online in The Lancet and at the American College of Cardiology meeting in San Francisco.
"The presence of atherosclerosis in premodern human beings suggests that the disease is an inherent component of human aging and not associated with any specific diet or lifestyle," the researchers concluded.
"What makes this so exciting is the sample size from four different regions of the ancient world," said Dr. Miguel Quinones of Weill Cornell Medical College.
While atherosclerosis has been found in mummies before, this is the largest study of its kind, said Quinones, who is scientific chair of the meeting.
For example, calcification consistent with atherosclerosis was identified by CT scanning in arteries of the naturally mummified "Iceman" from 3,000 BCE who was discovered in modern Italy.
And Thompson and colleagues have previously found evidence of atherosclerosis on CT scans of Egyptian mummies from several dynasties.
Quinones said he believes that ancient people probably had a more benign form of atherosclerosis.
"The modern diet and lifestyle may have changed it into a more aggressive form," he said.
The current study sought to determine whether something inherent to the Egyptian culture, such as a rich, high-fat diet, predisposed them to atherosclerosis, or whether atherosclerosis was common in other ancient societies as well.
For the study, dubbed HORUS for an ancient Egyptian deity, the researchers obtained whole-body CT scans of 137 mummies from four geographic regions or populations spanning more than 4,000 years: ancient Egypt, ancient Peru, the Ancestral Puebloans of southwest America, and the Unangan of the Aleutian Islands in current-day Alaska.
Atherosclerosis was regarded as definite if a calcified plaque was seen in the wall of an artery and probable if calcifications were seen along the expected course of an artery.
As determined by a panel of seven cardiovascular imaging physicians, probable or definite atherosclerosis was noted in 47 (34%) of the mummies overall: 25 had definite and 22 had probable disease.
Moreover, the scans detected evidence that then -- as now -- the disease spanned continents: 29 of the 76 Egyptian mummies, 13 of the 51 Peruvian mummies, two of five Ancestral Puebloans, and three of the five Unangan hunter gatherers.
Atherosclerosis was present in the aorta in 28 mummie (20 percent), iliac or femoral arteries in 25 (18 percent), popliteal or tibial arteries in 25 (18 percent), carotid arteries in 17 (12 percent), and coronary arteries in six (4 percent).
Of the five vascular beds examined, atherosclerosis was found in one to two beds in 34 (25 percent) mummies, in three to four beds in 11 (8 percent), and in all five beds in two (1 percent).
The scans also revealed that the mean age of death was 43 for those with atherosclerosis, compared with 32 for those without it.
Quinones said he found that interesting. "Then again, modern people live decades with atherosclerosis without dying from it," he said.
The researchers said the reason for the presence of atherosclerosis among all four populations is unknown. Their diets were quite disparate, as were the climates in which they lived, they wrote.
One common factor was the use of fire for warmth and cooking, the researchers said. "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," they wrote.
Additionally, all four populations lived at a time when infections were common and a major cause of death. "Chronic infection and inflammation may have promoted the inflammatory aspects of atherosclerosis," they wrote.
A limitation of the study was the use of calcification as a marker of atherosclerosis since there was no pathological confirmation that the calcifications represent atherosclerosis. Still, arterial calcifications on imaging studies in modern patients are deemed characteristic of clinical atherosclerosis, the researchers noted.
Moreover, "the location of the disease was similar to what we see in our patients," Thompson said.