Coronary heart disease, the most common cause of death in the modern world, is widely assumed to be a disease of our modern, sedentary lifestyles. However, a new study of Ötzi the Iceman – the 5,300 year old glacier mummy discovered in the Alps – published in Global Heart (the journal of the World Heart Federation) shows that not only does evidence of the condition go back at least 5,000 years, but that the underlying genetic risk factors were much the same then as they are now.
Even though the prevalence of atherosclerosis (the narrowing of the arteries due to plaques and fatty deposits) and other risk factors for heart disease, like levels of obesity and physical activity, have varied from ancient times to the modern day, CT scans had already shown that mummies from many different cultures, including Ötzi, had large build ups of calcified and fatty deposits in several major blood vessels. For Ötzi, this included the carotid arteries, distal aorta, and right iliac artery.
In Ötzi’s case, the authors say that traditional cardiac risk factors, such as being overweight, tobacco smoking, lack of physical activity, and a high fat diet, can generally be ruled out. So what did cause his condition?
After studying Ötzi’s genome, the authors found that this mummy had a very specific genetic mutation, namely that he was homozygous for the minor allele (GG) of rs10757274, located in chromosomal region 9p21.
Err… right… what exactly does THAT mean? According to the study’s authors, this mutation is currently regarded as being one of the strongest genetic predictors of heart attacks and has been confirmed in several studies as a major risk for CHD. In short, the finding suggests Otzi had the same genetic mutation.
What does this mean for the belief that living like our ancestors could keep us free from all risks of heart disease compared with modern day sedentism? According to the authors, this assumption is completely wrong:
“Going back thousands of years, our ancestors show signs of atherosclerosis… Even though they lived far different lives than we do, their environments and lifestyles were not protecting them against the development of atherosclerosis.”
They add: “What is similar between now and then is that our ancestors carried the same polymorphisms that predispose the carrier to CHD as we do today… But other conditions, such as infectious diseases, nutritional deprivation, and trauma, often resulted in death at an early age, before atherosclerotic heart disease had a clinical impact.”
Although Ötzi is the only ancient human remain in which a genetic predisposition for cardiovascular disease has been detected, future studies of other ancient DNA have the potential to provide more insights into possible changes of genetic risk factors over time.
The authors hope that the discovery will help produce a better understanding of how the interaction between genes and environment influence the development of heart diseases, which in turn may lead to a more effective prevention and treatment of the most common cause of death in the modern world.
Pretty amazing for a 5,300 year old frozen mummy!
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