A One hundred years ago, the leading causes of death in the industrial world were infectious diseases such as tuberculosis, influenza and pneumonia. Since then, the emergence of antibiotics, vaccines and public health controls has reduced the impact of infectious disease. Today, the top killers are non-infectious illnesses related essentially to lifestyle (diet, smoking and lack of exercise). The main causes of death in the United States in 1997 were heart disease, cancer and stroke. Chronic health problems, such as obesity, noninsulin-dependent diabetes and osteoporosis, which are not necessarily lethal but nonetheless debilitating, are steadily increasing. It is clear that economic and technical progress is no assurance of good health.
B Humans are qualitatively different from other animals because we manipulate the flow of energy and resources through the ecosystem to our advantage, and consequently to the detriment of other organisms. That is why we compete so successfully with other species. But with this success come some inherent failings, particularly in terms of our health.
C According to physician Boyd Eaton and his anthropologist colleagues, despite all our technological wizardry and intellectual advances, modern humans are seriously malnourished. The human body evolved to eat a very different diet from that which most of us consume today. Before the advent of agriculture, about ten thousand years ago, people were hunter-gatherers, the food varying with the seasons and climate and all obtained from local sources. Our ancestors rarely, if ever, ate grains or drank the milk of other animals.
D Although ten thousand years seems a long time ago, 99.99 percent of our genetic material was already formed. Thus we are not well adapted to an agriculturally based diet of cereals and dairy products. At least 100,000 generations of people were hunter-gatherers, only 500 generations have depended on agriculture, only ten generations have lived since the onset of the industrial age and only two generations have grown up with highly processed fast foods. Physicians Randolph Nesse and George Williams write: ‘Our bodies were designed over the course of millions of years for lives spent in small groups hunting and gathering on the plains of Africa. Natural selection has not had time to revise our bodies for coping with fatty diets, automobiles, drugs, artificial lights and central heating. From this mismatch between our design and our environment arises much, perhaps most, preventable modern disease.’
E Do we really want to eat like prehistoric humans? Surely ‘cavemen’ were not healthy? Surely their life was hard and short? Apparently not. Archaeological evidence indicates that these hunter-gatherer ancestors were robust, strong and lean with no sign of osteoporosis or arthritis – even at more advanced ages. Paleolithic humans ate a diet similar to that of wild chimpanzees and gorillas today: raw fruit, nuts, seeds, vegetation, fresh untreated water, insects and wild- game meat low in saturated fats. Much of their food was hard and bitter. Most important, like chimpanzees and gorillas, prehistoric humans ate a wide variety of plants – an estimated 100 to 300 different types in one year. Nowadays, even health-conscious, rich westerners seldom consume more than twenty to thirty different species of plants.
F The early human diet is estimated to have included more than 100 grams of fiber a day. Today the recommended level of 30 grams is rarely achieved by most of us. Humans and lowland gorillas share similar digestive tracts – in particular, the colon – but, while gorillas derive up to 60 percent of their total energy from fiber fermentation in the colon, modern humans get only about 4 percent. When gorillas are brought into captivity and fed on lower-fiber diets containing meat and eggs, they suffer from many common human disorders: cardiovascular disease, ulcerative colitis and high cholesterol levels. Their natural diet, rich in antioxidants and fiber, apparently prevents these diseases in the wild, suggesting that such a diet may have serious implications for our own health.
G Not all agricultural societies have taken the same road. Many traditional agriculturalists maintain the diversity of their diet by eating a variety of herbs and other plant compounds along with meat and grains. The Huasa people of northern Nigeria, for example, traditionally include up to twenty wild medicinal plants in their grain-based soups, and peoples who have become heavily reliant on animal products have found ways of countering the negative effects of such a diet. While the Masai of Africa eat meat and drink blood, milk and animal fat as their only sources of protein, they suffer less heart trouble than Westerners. One reason is that they always combine their animal products with strong, bitter antioxidant herbs. In other words, the Masai have balanced the intake of oxidising and antioxidising compounds. According to Timothy Johns, it is not the high intake of animal fat or the low intake of antioxidants, that creates so many health problems in industrial countries; it is the lack of balance between the two.
H Eating the right foods and natural medicines requires a sensitivity to subtle changes in appetite. Do I fancy something sweet, sour, salty, stimulating or sedating? What sort of hunger is it? And after consumption, has the ‘need’ been satisfied? Such subtleties are easily overridden by artificially created superstimuli in processed foods that leave us unable to select a healthy diet. We need to listen more carefully to our bodies’ cravings and take an intentional role in maintaining our health before disease sets in.
Reading Passage 2 has seven paragraphs, A – G.
Which paragraph contains the following information?
NB You may use any letter more than once.
14 a reference to systems for neutralizing some harmful features of modern diets
15 a suggestion as to why mankind has prospered
16 an example of what happens if a balanced, plant-based diet is abandoned
17 a chronological outline of the different types of diet mankind has lived on
18 details of which main factors now threaten human life
19 a reference to one person’s theory about the cause of some of today’s illnesses
20 details of the varied intake of early humans
Questions 21 – 26
Do the following statements agree with the claims of the writer in Reading passage 2? In boxes 21 -26 on your answer sheet, write
YES if the statement agrees with the claims of the writer
NO if the statement contradicts the claims of the writer
NOT GIVEN if it is impossible to say what the writer thinks about this
21 An increase in material resources leads to improved physical health.
22 Cereals were unknown to our hunter-gathering ancestors.
23 In the future, human bodies will adapt to take account of changes in diet.
24 Many people in developed countries have a less balanced diet than early humans.
25 Gorillas that live in the wild avoid most infectious diseases.
26 Food additives can prevent people from eating what their bodies need.