Many believe heart disease, which is the leading killer of Americans, is a lifestyle illness brought on by sedentary lifestyle and diets high in fat. About 600,000 or close to 25 percent of all premature deaths in the U.S. are caused by coronary heart disease according to the CDC. But evidence suggests that our ancient ancestors may have had the same risks as we have in the modern world.

Researchers used Whole Body CT scans on 137 mummies from places as far as the Andes, Egypt and even the freezing cold of the Arctic. They found that at least one-third of the preserved specimens had evidence of hardened arteries.

Scientists made use of the fact that when arteries harden because of deposits of cholesterol, they begin to calcify. This denser material appears brightly on whole body scans and is an easily detectable measure of the level of heart disease.

"I'd say we've shown heart disease is a serial killer that's stalked mankind for 4,000 years," said lead author Dr. Randall C. Thompson, cardiologist at Saint Luke's Mid America Heart Institute in Kansas City.

"Some people believe that a hunter-gatherer lifestyle should be more natural for our genetic machinery than the artificial food and inactivity that we have," said Thompson.

"[But] three out of the five of the Aleutian mummies had these calcifications, the sediment that forms in the arteries when the disease happens."

Around 38 percent of mummies from Egypt had signs of arthrosclerosis, or artery hardening. Around 25 percent of mummies from Peru were affected as well as 40 percent of preserved Pueblo Indians from the American Southwest and 60 percent of Unangans from the Aleutian Islands off the coast of North America.

Previous research was highly criticized because it looked at Egyptian mummies, which usually came from nobility and ate a rich diet, similar to our modern diet. The current research took a more varied approach and analyzed bodies from people that came from different cultures and social levels.

The researchers concluded that heart disease may just be a normal part of human aging.

"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 ageing."

Even if it is a part of normal human aging, it is life threatening and causes millions of premature deaths per year in the world. Medications to lower cholesterol are a billion dollar a year market.

The research published in the journal Lancet can be found here.