muscular, physically active, all of them resembling slim Western body-builders. When not carrying loads, they ran along steep mountain trails at a trot, and when carrying heavy loads they walked all day at my own unencumbered walking pace. I recall a small woman who appeared to weigh no more than 100 pounds, carrying a 70-pound rice bag resting on her back and suspended by a strap around her forehead, up boulder-strewn river beds and mountains. During those early years in New Guinea I never saw a single obese or even overweight New Guinean.
New Guinea hospital records, and medical examinations of New Guineans by physicians, confirmed this appearance of good health—at least in part. The non-communicable diseases that kill most First World citizens today—diabetes, hypertension, stroke, heart attacks, atherosclerosis, cardiovascular diseases in general, and cancers—were rare or unknown among traditional New Guineans living in rural areas. The absence of those diseases wasn’t just because of a short average lifespan: they still didn’t appear even among those New Guineans who did live into their 60s, 70s, and 80s. An early-1960s review of 2,000 admissions to the medical ward of the general hospital of Port Moresby (the capital and largest city) detected not a single case of coronary artery disease, and only four cases of hypertension, all four in patients of mixed racial origins rather than unmixed New Guineans.
But that’s not to say that traditional New Guineans enjoyed a carefree health utopia: far from it. The lifespans of most of them were, and still are, shorter than in the West. The diseases that killed them, along with accidents and interpersonal violence, were ones that have by now been largely eliminated as causes of death in the First World: gastrointestinal infections producing diarrhea, respiratory infections, malaria, parasites, malnutrition, and secondary conditions preying on people weakened by those primary conditions. That is, we Westerners, despite having traded our set of traditional human illnesses for a new set of modern illnesses, enjoy on the average better health and longer lives.
Already in 1964, the new killers of First World citizens were beginning to make their appearance in New Guinea, among those populations that had had the longest contact with Europeans and had begun to adopt Western diets and lifestyles. Today, that Westernization of New Guinea diets, lifestyles, and health problems is in a phase of explosive growth. Tens of thousands, perhaps hundreds of thousands, of New Guineans now work as businesspeople, politicians, airline pilots, and computer programmers, obtain their food in supermarkets and restaurants, and get little exercise. In cities, towns, and Westernized environments one commonly sees overweight or obese New Guineans. One of the highest prevalences of diabetes in the world (estimated at 37%) is among the Wanigela people, who were the first New Guinea population to become extensively Westernized. Heart attacks are now reported among city-dwellers. Since 1998 I have been working in a New Guinea oil field whose employees eat all three daily meals in a buffet-style cafeteria where one helps oneself to food, and where each dining table has a salt-shaker and sugar-shaker. New Guineans who grew up in traditional village lifestyles with limited and unpredictable food availability react to these predictable daily food bonanzas by piling their plates as high as possible at every meal, and inverting the salt and sugar dispensers over their steaks and salads. Hence the oil company hired trained New Guinean health workers to educate staff on the importance of healthy eating. But even some of those health workers soon develop Western health problems.
These changes that I have been watching unfold in New Guinea are just one example of the wave of epidemics of non-communicable diseases (NCDs) associated with the Western lifestyle and now sweeping the world. Such diseases differ from infectious (communicable) and parasitic diseases, which are caused by an infectious agent (such as a bacterium or virus) or a parasite, and which are transmitted (“communicate” themselves) from person to person through spread of the agent. Many infectious diseases develop quickly in a person after infection by the agent, such that within a few weeks the victim is either dead or recovering. In contrast, all of the major NCDs (as well as parasitic diseases and some infectious diseases, such as AIDS and malaria and tuberculosis) develop slowly and persist for years or decades until they either reach a fatal end or are cured or halted, or until the victim dies of something else first. Major NCDs in the current wave include various cardiovascular diseases (heart attacks, strokes, and peripheral vascular diseases), the common form of diabetes, some forms of kidney disease, and some cancers such as stomach, breast, and lung cancers. The vast majority of you readers of this book—e.g., almost 90% of all Europeans and Americans and Japanese—will die of one of these NCDs, while the majority of people in low-income countries die of communicable diseases.
All of these NCDs are rare or absent among small-scale societies with traditional lifestyles. While the existence of some of these diseases is attested already in ancient texts, they became common in the West only within recent centuries. Their association with the current explosive spread of the modern Western lifestyle around the world becomes obvious from their epidemics among four types of population. In the cases of some countries that became rich recently and suddenly, and most of whose inhabitants now “enjoy” the Western lifestyle—Saudi Arabia and the other Arab oil-producing nations, plus several suddenly affluent island nations including Nauru and Mauritius—the entire national population is at risk. (For instance, of the world’s eight countries with national diabetes prevalences above 15%, every one is either an Arab oil-producer or an affluent island nation.) Other epidemics are striking citizens of developing nations who emigrated to the First World, suddenly exchanged their formerly spartan lifestyle for a Western lifestyle, and are thereby developing NCD prevalences higher either than those of their countrymen who stayed home and continued their traditional lifestyle, or than those of long-term residents of their new host countries. (Examples include Chinese and Indians emigrating overseas [to Britain, the U.S., Mauritius, and other destinations more affluent than China or India], and Yemenite and Ethiopian Jews emigrating to Israel.) Urban epidemics are being recorded in many developing countries, such as Papua New Guinea, China, and numerous African nations, among people who migrate from rural areas to cities and thereby adopt a sedentary lifestyle and consume more store-bought food. Finally, still other epidemics involve specific non- European groups that have adopted a Western lifestyle without migrating, and that have thereby sadly become famous for some of the world’s highest prevalences of diabetes and other NCDs. Often-cited textbook examples include the Pima Indians of the U.S., New Guinea’s Wanigela people, and numerous groups of Aboriginal Australians.
These four sets of natural experiments illustrate how the adoption of a Western lifestyle, no matter what leads to it, by people previously with a traditional lifestyle results in NCD epidemics. What these natural experiments don’t tell us, without further analysis, is which particular component or components of the Western lifestyle trigger the epidemic. That lifestyle includes many components occurring together: low physical activity, high calorie intake, weight gain or obesity, smoking, high alcohol consumption, and high salt consumption. Diet composition usually shifts to low intake of fiber and high intakes of simple sugars (especially fructose), saturated fats, and trans-unsaturated fats. Most or all of these changes happen simultaneously when a population Westernizes, and that makes it difficult to identify the relative importance of individual ones of these changes in causing an NCD epidemic. For a few diseases the evidence is clear: smoking is especially important as a cause of lung cancer, and salt intake is especially important as a cause of hypertension and stroke. But for the other diseases, including diabetes and several cardiovascular diseases, we still don’t know which of these co-occurring risk factors are most relevant.
Our understanding of this field has been stimulated especially by the pioneering work of S. Boyd Eaton, Melvin Konner, and Marjorie Shostak. Those authors assembled information on our “Paleolithic diet”—i.e., the diet and lifestyle of our hunter-gatherer ancestors and of modern surviving hunter-gatherers—and on the differences between the principal diseases affecting our ancestors and modern Westernized populations. They reasoned that our non-communicable diseases of civilization arise from a mismatch between our bodies’ genetic constitution, still largely adapted to our Paleolithic diet and lifestyle, and our current diet and lifestyle. They proposed tests of their hypothesis and offered recommendations about diet and lifestyle to reduce our exposure to our new diseases of civilization. References to their original articles and book will be found under the Further Readings for this chapter.
Non-communicable diseases associated with the Western lifestyle offer perhaps this book’s most immediately practical example of the lessons that can be extracted from traditional lifestyles. By and large, traditional people don’t develop the set of the NCDs that I’ve discussed, while by and large most Westernized people will die of these NCDs. Of course, I’m not suggesting that we adopt a traditional lifestyle wholesale, overthrow state governments, and resume killing each other, infanticide, religious wars, and periodic starvation. Instead, our goal is to identify and adopt those particular components of the traditional lifestyle that protect us against NCDs. While a full answer will have to wait for more research, it’s a safe bet that the answer will include traditional low salt intake and won’t include traditional lack of state government. Tens of millions of people around
