A History of Disease: How Economic Priorities and Evolving Lifestyles Feed Epidemics

When I was studying human evolution at the University of Toronto I learned that diseases are a direct result of the increasing complexity of human social organization from hunter-gatherers to early farmers, city-states and empires. An understanding of the history of disease is more than just academic; it is important to know how everything in nature hangs together, and that our compartmentalizing approach creates more opportunities for sickness than nature itself.

“Most professionals and scientists, in the interest of efficiently and effectively solving different kinds of problems, are trained to see only certain things. Doctors see individual patients, public health workers see crowds and toilets, sociologists see a community of temples and roads, ecologists see a living multifaceted community of communities, and many of us, increasingly, see just a big mess”, writes Guelph University professor of veterinary science and epidemiology Dr. David Waltner-Teows. His new and insightful book, The Chickens Fight Back: Pandemic Panics and Deadly Diseases That Jump from Animals to Humans, is a page-turner presented with irreverent humour and hair-raising anecdotes from his worldwide research into disease ecology. He shows how the past complicates current public and individual health.

History is central to ecology. Consider cancer, which is essentially an epidemic caused by a near-total disregard for its history and ecology. On human chromosome 17 is found gene TP53 whose protein p53 works in every cell of our bodies to protect us against incorrectly replicated (potentially cancerous) cells by forcing such cells to commit suicide (apoptosis); p53 failure is involved in all cancers. Geneticists call it “the guardian of the genome”. Apoptosis events occur between 15 to 30,000 times daily in a healthy person; it is present in all mammals and some amphibians and fish.

In its June 28, 2007 issue, Nature reported that p53’s complex activity has now also been found in the fruit fly, which appeared about 500 million years ago, and a nematode worm C. elegans, which goes back 300 million years. (Today it includes hookworms, roundworms, pinworms, and causes Elephantiasis and trichinosis.) Imagine, these flies and worms can live in us and make us sick, but simultaneously are equipped to protect themselves against cancer! This discovery shows that protection against aberrant cell reproduction is part of the basic design of life, a universal troubleshooting mechanism for self-protection.

It so happens that throughout life’s evolutionary history, p53 encountered few enemies until we, the evolutionary Johnny-come-latelies, invented tens of thousands of carcinogens, like pesticides. Therefore, ecologically informed cancer treatment would start by removing all known carcinogens from our environment and bodies and then provide p53 with whatever it needs to function. (Harvard scientists found that Beta carotene turns it back on! Hence all that carrot juice in the Gerson Therapy treatment protocol.)

Ecological medicine respects the history of a disease, and the system within which it is embedded, because in dynamic living systems the past is life and death for the present. Preventive nutrition, lifestyle education, and many new epidemiological strategies now incorporate historical-ecological thinking. A simple example is a doctor treating colorectal cancer and insisting the patient stop smoking – which also has an effect on the patient’s family and the tobacco industry.

Diseases are unintended byproducts of human activity. The former director of the University of Toronto’s Institute for Environmental Studies, Henry Regier, observed that with every new development there inevitably appear “new domains of ignorance” from which unexpected problems arise. Nature revels in the creation of a spectacular diversity of life forms – as well as in spawning an inexhaustible variety of ways by which to knock off its productions, presumably to make room for new and improved creatures. In infectious disease research those domains of ignorance have exploded: recently, experts in the origins of infectious diseases called for the creation of “a global early warning system” to monitor the emergence of new pathogens (Nature, May 17, 2007).

The information on how diseases evolved and came to stay comes from fossilized human and animal bones; fossil turds (coprolites) which reveal who ate what and whom, and harboured which disease agents; ancient burials (the oldest from 150,000 years ago contain Neanderthals); mummies, and bones from cemeteries throughout history which show death from sexually transmitted diseases, chronic malnutrition, vitamin D deficiency (which killed the Vikings in North America some 900 years ago), or population-wide chronic lead poisoning such as among the Romans. Fossilized bacteria, close to a billion years old from Earth’s earliest times, show that they have been here almost forever and will undoubtedly outlive us.

Humans began only about seven million years ago, and a mind-boggling number of ancient life forms decided that we are a convenient host: the number of bacteria, viruses, fungi, and parasites resident in and on our bodies, even when we are in excellent health, exceeds by billions the number of cells from which we are composed. The human body is an omnibus carrying an ecological universe. Most of the time we all are a peaceable kingdom; they make us ill only when malnutrition (e.g. through lack of food, nutrient-poor processed foods, or fungal and chemical poisons) upsets this grand corporation by weakening the immune system. Thus the fungus Candida albicans is part of our normal gut flora and becomes a health hazard only when the immune system can’t keep its numbers down.

Most diseases are caused by non-residents which may overwhelm immunity and bring on acute illness (e.g. the plague, measles, dysentary), or chronic conditions (e.g. Lyme disease, streptococcal bacteria followed by heart disease); they often also interfere with the genetic repair system (e.g. bacterial-mediated cancer from H. pylori).

Infectious diseases seem not to have been a problem during the Paleolithic or Old Stone Age era because human groups likely did not exceeded 50-60 individuals, which is still the preferred population density among modern hunter-gatherers; any more, and they become stressed out and then split up. Since small numbers don’t generate hygiene and contact conditions favourable for disease transmission, evidence for infectious disease is limited to anaerobic bacteria which thrive in oxygen-free bodily areas such as our gums, around our tooth roots and various unmentionable body parts. One anaerobic bacteria mediated death is known from the very early human evolutionary stage, a 14-year old Homo erectus boy whose complete fossilized remains were found near Lake Turkana in East Africa; he died 1.5 million years ago from septicemia when a lower molar erupted sideways and was unable to surface, causing tissue damage. The next evolutionary human type, the Neanderthals, shows the first evidence of arthritis some 100,000 years ago, possibly because they moved so far north and their staple diet was mostly meat.


For bacteria, viruses and parasites to establish themselves, they need stable and large sedentary groups. Whooping cough and streptococcal bacteria need a considerable human (host) density to succeed, and that’s what happened in the Neolithic or early farming period some 20,000 years ago. In rapid succession Yellow Fever evolved, which thrives almost exclusively in human water storage containers. Malaria, transmitted by mosquitoes (themselves possibly five million years old), became one of the greatest killers as a direct consequence of wet rice planting. Our co-existence with them was so intense and long that in Southeast Asia some humans developed a genetic adaptation, such as sickle cell anemia, which confers immunity against malaria. (The blood disease thalassemia may have resulted from a parasite, Plasmodium falciparum, which established itself so thoroughly that the immune response became a hereditary abnormality.)

Most mould-based diseases resulted from storing food, but with this came the discovery of natural antibiotics such as penicillin and tetracycline, already known in antiquity for their healing properties. The domestication of horses gave us tetanus and the common cold; domestication of cattle gave us measles, smallpox, and diptheria. From pigs and chickens came influenza. In Middle Kingdom Egypt, about 3,000 years ago, some domesticated animals helped transform a normally harmless stomach flu virus into polio in humans. All these so-called zoonoses were usually harmless to animals, but in us cause clear and present danger.

Epidemics became possible with the rise of cities and states, and conquering armies carried them into areas whose people had no immunity to them. Well-documented disease waves accompanied the Mongol invasions of Europe around 1200, the establishment of trade routes connecting China with India and both with the Mediterranean Sea around 1400, and the European invasions of Africa, the Americas, Asia and Australia, starting around 1500. These brought smallpox and more, while the conquerors took back and spread syphilis and cholera.

Abandoning stone tools and the raw fast-food cuisine derived from hunting and gathering, in favour of storage and cooking in clay pots, invited poisoning of many kinds and nutrient depletion. The use of iron pots caused food to lose vitamin C, the most vital nutrient for creatures like us who evolved in the fruit-rich tropics; scurvy is rare in pre-history but became a killer when sailing ships started international trade. The convenience of long-term storage has caused nutrient reduction for thousands of years, and is still with us in every modern supermarket selling foods brought from afar.

We know from current hunter-gatherer groups that their daily intake of vitamin C, for example, is about 30,000 mg per person – something only achievable for us with huge amounts of supplements or intravenous therapy.

Vitamins and phytonutrients degrade over time and through exposure to air and light. This shows in the bones of people, starting some 10,000 years ago. With storage and long-distance trade came reliance on staple foods. Ancient as well as contemporary mono diets compromise immunity and cause a state of chronic malnutrition with their attending chronic diseases. This shift shows up in antiquity as osteoporosis and diabetes. Even repetitive strain injury of the knees and wrists is first observed in women buried some 8,000 years ago in what is now Israel; they had spent their lives mashing and grinding early domesticated wheat, which is less nutritious than wild wheat and has less inflammation-fighting and DNA supporting vitamin E.

Storage also caused some cultural tragedies: Ergotism, a fungal poisoning that produces LSD-type hallucinations, was apparently the cause of the witch hunt in Salem, New England, in 1691. The “satanic possessions” and deaths of children and cattle were due to improper storage of rye, making it psychedelic and neuro-toxic.

Excessive need for salt for successful long-term storage initiated the potential for cardiovascular disease because this upsets the sodium/potassium balance, and so hypertension is first described in Egyptian texts in 2,500 BC.

Mono diets and their inherent disregard for the actual nutritional requirements of our organs allowed for the development of diabetes, rickets, birth defects, bone malformations, and especially problems with pregnancy and obstetrics. Dr. Weston Price documented this in his global research into the relationship between disease and chronic deficiencies of vitamins A, C and E in populations switching to processed foods. Asthma was first described by Hippocrates (ca. 250 BC) who suggests that it is a consequence of poor living conditions and excessive exposure to dust in grain processing. Allergies were rare in ancient times but became a dominant illness with the advent of the industrial age whose toxic by-products often prove to be too much for our immunity.

Colonizing certain areas can inadvertently lead to new illnesses: Multiple sclerosis is triggered by vitamin D deficiency which, in turn, is caused by too little sunlight; MS does not occur near the Equator and can be prevented and even treated successfully with vitamin D, which also acts as hormone. (The Inuit had no MS because they ate vitamin D-rich raw livers.) Iodine-deficient soils have caused goiter in those regions. Areas in the world where the soil is rich in selenium have virtually no AIDS, while countries with the least of this mineral have the most cases, as medical geographer Harold Foster of the University of British Columbia has documented.

Cultural preferences have turned out to be key to cancer morbidity. A comparison of China with the U.S. undertaken by Colin Campbell’s team from Cornell University showed, in the largest and longest study of this kind ever done, that reliance on plant proteins, in preference to animal proteins, protects against cancer and even against exposure to chemical carcinogens!


Today, there are about 175 new human diseases making their way around the globe. The crowding of food-producing animals (from which they, unlike hunter-gatherers, cannot escape) makes them into the perfect ecological disease-producing community for maintaining old pathogens and allowing new ones to evolve as antibiotic resistance increases.  They require enormous amounts of antibiotics, all of which are potent carcinogens in the meat we eat. In this context, Dr. Waltner-Toews’ discussion of current politics of disease-control and how economic priorities feed epidemics is truly a revelation.

The new frontier of diseases is undoubtedly that brave new world of chemically-induced ones, like Multiple Chemical Sensitivity, hormone disrupting chemicals which affect reproduction and fertility, and novel pathogens being developed and often already used for biological warfare purposes. Meanwhile, global warming helps to move old diseases into new areas.

Dr. Waltner-Toews observes, “It turns out that controlling some of the great infectious-disease scourges of human development – smallpox, tuberculosis, and the plague – was the easy part” of medicine. Given that the current disease burden is an amplification of what ancient cultural behaviour unleashed unconsciously, it is of utmost importance to focus consciously and thoughtfully on “our struggle with infectious diseases [which] is a war against ourselves,” he  writes. What is needed is “global solidarity and keen, ecological awareness – we must dig into our history, rediscovering the roots of what it is to be human [which] in this age of gun-toting peace-makers, God-fearing hell-raisers, and utopian pillagers is no small task.”

To survive means to adjust continuously, especially to our peculiarly creative and destructive selves.


Cambridge World History of Human Disease, Cambridge 1993

– S. R. Brown, Scurvy, Thomas Allen, 2003

– T.C. Campbell, The China Study, Benbella, 2005

– D.J. Diamond, Guns, Germs and Steel, Norton, 1997

– M.N. Cohen, Health and the Rise of Civilization, Yale, 1989

– D. Foster, What Really Causes AIDS, Trafford, 2002

– Dr. G. Hart, ed. Disease in Ancient Man, Clarke Irwin, 1983

– M. Jackson, Allergy: History of a Modern Malady, Reaktion, 2006

– M. K. Matossian, Poisons of the Past, Yale, 1989

– Dr. W. Price, Nutrition and Physical Degeneration, Keats, 1989

– Dr. D. Waltner-Toews, The Chickens Fight Back, Greystone, 2007

Helke Ferrie is a medical science writer with a master's degree in physical anthropology. Her specialty lies in investigative research into ethical issues in medicine and the politics of health. She started her investigative journalism career in the mid-1990s, looking at issues of medicine and environment. She has been a regular contributor to Vitality Magazine ever since. Helke has also authored several books on various subjects including: "Ending Denial: The Lyme Disease Epidemic", "What Part of No! Don't They Understand: Rescuing Food and Medicine from Government Abuse", and "The Earth's Gift to Medicine". Read her article: When governments abandon the public interest — look out for your own health Find her book -What Part of No! Don't They Understand Helke has also been a regular contributor for the Vitality Magazine. Links to few of her articles: The Tyranny of Government Protection Success Story - How I Recovered from Lyme Disease IN THE NEWS: Fluoride Dangers; Roundup Lawsuits; Lyme Disease Epidemic Helke Ferrie now lives a retired life and can be reached at helkeferrie@gmail.com

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