Once you hit a certain age, visiting a doctor is basically a guilt trip. All that satisfying stuff you eat, drink or smoke is killing you, a white-coated overachiever tells you. You need to exercise and lose weight, or the grim reaper will be at your door long before you’re ready. And it will all be your fault.
There’s truth in that message. The primary causes of death in Western society today are cardiovascular disease and cancer, two diseases that are very much tied up with what we put in our bodies and how we use and abuse them. If you eat a healthy diet, exercise regularly and abstain from smoking and excessive drink, your odds of living to a ripe old age do in fact increase.
But how much? Are cancer and cardiovascular disease primarily caused by the excesses of life in a modern industrial society? Or are they the inevitable end of a long and otherwise healthy life? At some level, heart disease and cancer must kill so many of us simply because in the past, plagues and saber-toothed cats beat them to it.
CT scans of ancient mummies from Egypt, Peru, Alaska and the U.S. Southwest suggest that clogged arteries have always been a fact of life, even for people who defined fast food as a swift-running ungulate. Researchers recently examined 137 mummies for evidence of calcified plaques associated with major arteries, and found that 34 percent of them probably had some atherosclerosis when they died.
Using skeletal features to estimate how old these mummies were at death, researchers showed that atherosclerosis risk increased with age. About 15 percent of those who died before age 30 had sclerotic deposits, an April 6 paper in Lancet reported, but the rate among those who died in their 40s was more than 50 percent.
The paper’s authors, an international team of pathologists and archaeologists, looked at diet and lifestyle factors that might have encouraged atherosclerosis. But there were no epidemiological smoking guns. The Egyptians ate something very close to the “Mediterranean diet” that a recent Spanish study showed greatly benefits cardiovascular health. The Unangans of coastal Alaska ate a diet high in fish oil, which has been shown to lower cholesterol and potentially reduce cardiovascular risk. In Peru and the U.S. Southwest, people hunted, farmed and gathered a richly varied diet devoid of dairy, processed sugar and lots of other stuff that tastes really good.
The one risk factor all of these ancient people probably did face was inflammation. In the last decade or so, it has become apparent that the processes our bodies use to fight off infection and heal injury also do a lot of damage. Chronic inflammation — even something as apparently trivial as gum disease — has been shown to boost a person’s risk of heart attack.
In a world without antibiotics, flush toilets and Purell, the immune systems of the ancients would have been in a constant state of agitation. Other mummy studies have shown, for example, that tuberculosis was widespread in Egypt and present in the New World during ancient times.
Inflammation has been associated with cancer as well. But for some reason, researchers have found very few signs of cancer in ancient mummies. Writing in 2010 in Nature Reviews Cancer, two researchers proposed that this dearth of evidence suggests cancer may have been rare before modern times. They weren’t arguing that cancer didn’t exist at all before people started eating Cheetos and smoking Marlboros: One of the authors, retired pathologist and biologist Michael R. Zimmerman of Villanova University near Philadelphia, recently diagnosed a rectal carcinoma in an Egyptian mummy dating to the 3rd or 4th century A.D. But such diagnoses are rare. It could be that until recently people just didn’t live long enough to develop cancer very often. Or, he and A. Rosalie David of the University of Manchester in England suggested, it could be that modern life immerses us in a sea of carcinogens that ancient people never encountered.
Then again, it’s also possible that researchers just haven’t looked hard enough. When scientists from Portugal and Egypt did CT scans on three mummies housed at the National Archaeological Museum in Lisbon, they found bone lesions in and around the pelvis of a man who died 2,250 years ago that indicated prostate cancer. That discovery, described in 2011 in the International Journal of Paleopathology, was only the second oldest diagnosed case of prostate cancer: The oldest was seen in the skeleton of a Scythian king who died 2,700 years ago. Another study found 13 malignant bone tumors among 3,967 buried in Hungary between the 3rd and 16th centuries. That doesn’t sound like many, but similar cancers are no more common today.
Knowing the extent to which modern diseases are products of our environment could offer valuable clues to preventing the biggest killers of our time. But as we search for clues to our own demise in the remains of those who met theirs so many centuries ago, we should also have the wisdom to remember the message that is clearly written on every mummy’s face: Soon enough, all of us will meet their fate.