Like nearly 4.6 million Americans, ancient hunter-gatherers also suffered from clogged arteries, revealing that the plaque build-up causing blood clots, heart attacks and strokes is not just a result of fatty diets or couch potato habits, according to new research in the journal The Lancet.
The researchers performed CT scans of 137 mummies from across four continents and found artery plaque in every single population studied, from pre-agricultural hunter-gatherers in the Aleutian Islands to the ancient Puebloans of southwestern United States.
Their findings provide an important twist to our understanding of atherosclerotic vascular disease, which is the leading cause of death in the developed world: while modern lifestyles can accelerate the development of plaque on our arteries, the prevalence of the disease across human history shows it may have a more basic connection to inflammation and aging.
“This is not a disease only of modern circumstance but a basic feature of human aging in all populations,” says Caleb Finch, PhD, USC University Professor, ARCO/ Kieschnick Professor of Gerontology at the USC Davis School of Gerontology, and a senior author of the study. “Turns out even a Bronze Age guy from 5,000 years ago had calcified, carotid arteries,” Finch says, referring to Otzi the Iceman, a natural mummy who lived around 3200 BCE and was discovered frozen in a glacier in the Italian Alps in 1991.
With Gregory Thomas, M.D., MPH of Long Beach Memorial, Finch was part of a team that previously showed Egyptian mummies had calcified patches on their arteries indicative of advanced atherosclerosis (from the Greek arthero, meaning “gruel” and scler, meaning “hard”).
But ancient Egyptians tended to mummify only royalty or those who had privileged lives. The new study led by Thomas and Randall Thompson, M.D., of Saint Luke’s Mid America Heart Institute examined mummies from four drastically different climates and diets – and from cultures that mummified regular people, including ancient Peruvians, Ancestral Puebloans, the Unangans of the Aleutian Islands and ancient Egyptians.
“Our research shows that we are all at risk for atherosclerosis, the disease that causes heart attacks and strokes – all races, diets and lifestyles,” says Thomas, medical director of the MemorialCare Heart & Vascular Institute, Long Beach Memorial. “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.”
“We are not advocating for a nihilistic approach to vascular disease risk factor management,” says Michael Miyamoto, M.D., Mission Internal Medical Group. “Humans are intrinsically at-risk for vascular disease. In turn, we need to be more diligent in managing the risk factors. Our next study will focus on exploring some of the specific processes by which aging affects the development of atherosclerosis.”
Overall, the researchers found probable or definite atherosclerosis in 34 percent of the mummies studied, with calcification of arteries more pronounced in the mummies that were older at time of death. Atherosclerosis occurred in half of those older than 40-years-old. Atherosclerosis was equally common in mummies identified as male or female.
“I was surprised by the degree of atherosclerosis evidence on the scans,” says James Sutherland, M.D., who practices at Saddleback Memorial in Laguna Hills. “Personally, I thought that we would see fewer signs of atherosclerosis because of their lifestyles, but what we found was quite similar to what we see in modern-day Europeans and Americans.”
“One particular interesting finding for me was that atherosclerosis presented itself at the same age and in the same degree in women as it did in men,” says M. Linda Sutherland, M.D., Newport Diagnostic Center. “Today, women present with the same severity of atherosclerosis, but not until much later in life compared to their male counterparts. Traditional roles and lifestyles of women in these cultures, including cooking over an open fire, may have led them to have these conditions sooner.”
The international team of researchers will next seek to biopsy ancient mummies to get a better understanding of the role chronic infection, inflammation and genetics in promoting the prevalence of atherosclerosis.
“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 said, pointing to studies that show larger plaques in children exposed to household tobacco smoking or who are obese.