A new study on mummies suggests that heart disease is not a modern day illness and could be a natural part of human aging.

"Heart disease has been stalking mankind for over 4,000 years all over the globe," lead author Dr. Randall Thompson, a cardiologist at Saint Luke's Mid America Heart Institute in Kansas City, said.

Researchers say their findings, published in the Lancet, show the disease might not be directly tied to contemporary risk factors like smoking, eating unhealthy foods, and not exercising.

"I think it's fair to say people should feel less guilty about getting heart disease in modern times," Thompson said. "We may have oversold the idea that a healthy lifestyle can completely eliminate your risk."

The study is part of the largest-ever study of mummies and heart disease.

Critics warned against reading too much into the results, saying there could have been other factors that caused the clogged arteries. They pointed to the many studies showing strong links between lifestyle factors and heart disease.