Atherosclerosis Evident in Four Ancient Populations, Including Hunter-Gatherers
SAN FRANCISCO, California — Whole-body computed tomography (CT) scans of mummies from four geographical regions across a period of 4000 years suggest that atherosclerosis was more common in ancient populations than previously believed [1] Studying individuals from ancient Egypt, ancient Peru, ancestral Puebloans of southwestern America, and hunter-gatherers from the Aleutian Islands, researchers were able to identify atherosclerosis in more than one-third of the mummified specimens, raising the possibility that humans have a natural predisposition to the disease.
"Our findings greatly increase the number of ancient people known to have atherosclerosis and show for the first time that the disease was common in several ancient cultures with varying lifestyles, diets, and genetics, across a wide geographical distance and over a very long span of human history," according to the researchers. "These findings suggest that our understanding of the causative factors of atherosclerosis is incomplete and that atherosclerosis could be inherent to the process of human aging."
The study is published March 10, 2013 in the Lancet to coincide with a presentation here at theAmerican College of Cardiology 2013 Scientific Sessions.
Led by Dr Randall Thompson (University of Missouri-Kansas City School of Medicine), who previously presented data showing that heart disease was evident in the imaging scans of 3500-year-old Egyptian mummies, the research is unique in that it assesses atherosclerosis across four different preindustrial populations from different geographical regions. The ancient Egyptians and Peruvians were farmers, the ancestral Puebloans were forager-farmers, and the Unangans of the Aleutian Islands were hunter-gatherers without agriculture. None of the cultures was known to be vegetarian, and all were believed to be quite physically active.
"The diets of these peoples were quite disparate, as were the climates," according to Randall and colleagues. "Indigenous food plants varied greatly over the wide geographical distance between these regions of the world. Fish and game were present in all of the cultures, but protein sources varied from domesticated cattle among the Egyptians to an almost entirely marine diet among the Unangans."
In total, whole-body CT scans were performed on 137 mummies, including 76 ancient Egyptians, 51 ancient Peruvians, five ancestral Puebloans, and five Unangan hunter-gatherers. Probable or definite atherosclerosis was evident in 34% of the mummies--29 ancient Egyptians, 13 ancient Peruvians, two ancestral Puebloans, and three Unangan mummies had documented evidence of atherosclerosis as defined by calcified plaque in the wall of the artery (or probable atherosclerosis if calcifications were observed along the course of the artery).
Atherosclerosis was observed in the aorta of 28 mummies and in the iliac or femoral arteries of 25 mummies. Another 25 mummies had atherosclerosis in the popliteal or tibial arteries, while 17 had carotid-artery disease and six had atherosclerosis observed in the coronary arteries. One in four of the mummies had atherosclerosis in at least two vascular beds. Based on calculations using architectural changes in the bone structures, the mean age at the time of death was 43 years old, and age was positively correlated with atherosclerosis.
Thompson and colleagues note that all four populations lived at a time when infections would have been a common cause of death. The high level of chronic infection and inflammation might have promoted the inflammatory aspects of atherosclerosis, they write, which would be consistent with the accelerated course of disease observed in patients with rheumatoid arthritis and lupus.
"In conclusion, atherosclerosis was common in four preindustrial populations, including a preagricultural hunter-gather population, and across a wide span of human history," they write. "It remains prevalent in contemporary human beings. 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."
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