A study of Egyptian mummies and ancient skeletons has found little evidence that they suffered from cancer. The authors of the study suggest that this means cancer is a modern disease.
鈥淭his might be related to the prevalence of carcinogens in modern societies,鈥� write of the University of Manchester, UK and Michael Zimmermann of Villanova University, Pennsylvania. Cancers, they add, are 鈥渓imited to societies that are affected by modern lifestyle issues, such as tobacco use and pollution resulting from industrialisation鈥�.
The assertions have dismayed cancer researchers, and have led to . So what should we make of the evidence from the mummies, and do they justify laying the blame for cancer firmly on modernity? 麻豆传媒 investigates.
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What did the study find?
In a review of published analyses of tens of thousands of ancient skeletons and hundreds of mummies, David and Zimmermann found only a handful of cases of cancer. One recent finding, of colorectal cancer, was identified as the first ever discovered in a mummy. They also examined ancient texts and literature from Egypt and Greece, and say that there鈥檚 little sign that cancer was a common ailment.
Is this the basis of their suggestion that cancer is a modern disease?
Yes. Modern lifestyles, and exposure to many more carcinogens than in antiquity.
How have cancer charities and research organisations reacted to the conclusions?
They are not happy. put out by the University of Manchester saying 鈥淭here is nothing in the natural environment that can cause cancer. So it has to be a man-made disease, down to pollution and changes to our diet and lifestyle鈥� caused particular consternation.
What鈥檚 so wrong with that?
There are dozens of natural causes of cancer, including ultraviolet light from the sun, natural radiation from radionuclides such as radon in rocks, and infection by viruses that trigger cancer, such as the human papilloma virus, which causes cervical cancer and hepatitis viruses that can cause liver cancer. Likewise, soot and smoke from fire contain a multitude of carcinogens, as do fungal aflatoxins deposited on peanuts. 鈥淎nd that鈥檚 to say nothing of cancers caused by genetic inheritance,鈥� says Kat Arney of Cancer Research UK.
But aren鈥檛 there elements of modern life that cause cancers?
Yes, indeed, but most of them are down to poor lifestyle choices that people can do something about, not, as implied, because they are drowning in a sea of carcinogens from which there is no escape.
Smoking is the most significant of these, causing around a quarter of all cancers globally. 鈥淭hose deaths could be avoided by a complete ban on smoking,鈥� says Joachim Sch眉z, head of the section on environment and radiation at the International Agency for Research on Cancer in Lyon, France, which evaluates all potential cancer risks.
Other major lifestyle factors that pose cancer risks include heavy drinking, which can lead to liver and gullet cancers, sunbathing, which can lead to skin cancer, and obesity and lack of exercise, which can promote cancers of the gut. 鈥淧esticides and some industrial chemicals can cause cancer, but their overall contribution is very small,鈥� says Sch眉z.
Is there anything else wrong with the study?
Almost all the mummies and skeletons were of people who died before the age of 50. 鈥淎geing is one of the major causes of cancer,鈥� says Sch眉z. He dismissed as 鈥渨eak鈥� the authors鈥� argument that they could find evidence for other diseases of ageing, such as arthritis and hardening of the arteries, and that cancer should therefore have shown up too. 鈥淚n men today, 90 per cent of cancers occur after 50,鈥� he says. 鈥淪o if you examined the bodies of 1000 modern men who died before 50, you wouldn鈥檛 find many cancers either.鈥�
Any other gripes?
Yes. One of the main arguments for cancer being an affliction of modernisation was the apparent lack of evidence for 鈥渃ommon鈥� bone cancers in children. But again, the figures don鈥檛 bear this out. 鈥淚t鈥檚 true it鈥檚 a relatively common cancer, but even still it only affects 1 in 10,000 children,鈥� Sch眉z says. 鈥淪o even if you have 10,000 childhood mummies, you鈥檇 be lucky to find one.鈥�
David concedes that these are valid criticisms. 鈥淲e鈥檙e not saying what the explanation is, we鈥檙e proposing it鈥檚 modern living also taking into account that people living longer might be to blame,鈥� she says.
What do cancer charities say about the potential impact of the study?
Their big fear is that by blaming industrialisation generally for cancer, it will make people feel helpless about the situation, and divert attention from the many changes they can make to their behaviour to reduce their risk, such as quitting smoking, exercising more, drinking less and eating more healthily.
And what of the history of cancer? Are there other accounts?
Yes. The American Cancer Society has , and there鈥檚 more and their response to the story .
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