Heart disease isn't entirely related to modern lifestyle, but has affected humans since ancient times. A new study has provided evidence that hunter-gatherers, too, suffered from clogged arteries. Researchers say that every population in the world has an inherent risk of atherosclerosis and that diets don't provide us much protection from the disease.
The study included 137 mummies from four continents. Researchers scanned these mummies and found that artery plaque was present in every specimen, from "preagricultual hunter-gatherers in the Aleutian Islands to the ancient Puebloans of southwestern United States," according to a news release.
"This is not a disease only of modern circumstance but a basic feature of human aging in all populations. Turns out even a Bronze Age guy from 5,000 years ago had calcified, carotid arteries," said Caleb Finch, USC University professor and senior author of the study.
Finch was referring to a natural mummy called Otzi the Iceman, who was found in a glacier in the Italian Alps.
Previous research on Egyptian mummies had shown that people were in advanced stages of atherosclerosis (Greek -arthero = "gruel" and sclera = "hard"), as these mummies had clogged arteries. However, the research on Egyptian mummies couldn't be generalized as these mummies were people from royal families and probably led lifestyles that increased the risk of heart disease.
But, the new study included ancient Peruvians, Ancestral Puebloans, the Unangans of the Aleutian Islands and ancient Egyptians - each with varied diets and lifestyles. Another related study has found that the ancient Peruvians, much like modern people, were really stressed and had high levels of the stress hormone cortisol in the body.
"Our research shows that we are all at risk for atherosclerosis, the disease that causes heart attacks and strokes - all races, diets and lifestyles. Because of this we all need to be cautious of our diet, weight and exercise to minimize its impact. The data gathered about individuals from the pre-historic cultures of ancient Peru and the Native Americans living along the Colorado River and the Unangan of the Aleutian Islands is forcing us to think outside the box and look for other factors that may cause heart disease," said Gregory Thomas of Long Beach Memorial, and one of the study authors.
Heart disease accounts for one out of every four deaths in the U.S., says Centers for Disease Control and Prevention (CDC). About 600,000 people die from heart disease in the country each year.
"We found that heart disease is a serial killer that has been stalking mankind for thousands of years," Randall Thompson, of Saint Luke's Mid America Heart Institute, added.
Researchers found that both men and women were equally at risk from dying due to heart disease. According to Thompson, the study challenges the common assumption that heart disease is largely due to lifestyle changes that occurred post-industrialization. The study also shows that reverting back to an agriculture-dominated society wouldn't do the human heart any good and that we haven't yet fully understood how heart disease evolves over time. Researchers speculate that atherosclerosis may be a part of the normal aging process.
The study is published in the journal The Lancet.
In the next phase of the study, researchers will be conducting an extensive analysis of various factors like infectious diseases, genetics and environmental factors that could affect the growth of heart disease.
"Atherosclerosis starts very early in life. In the United States, most kids have little bumps on their arteries. Even stillbirths have little tiny nests of inflammatory cells. But environmental factors can accelerate this process," Finch concluded.