Deadly Harvest: The Intimate Relationship Between Our Heath and Our Food (39 page)

Eating in accordance with the Savanna Model is the ideal and there are no other special measures to take. Just make sure that your teeth, whether original or artificial, are working efficiently. Many old people eat badly simply because they choose foods that don’t need chewing. As an older person, make sure that you are eating the proper rations of fruit, salads, and vegetables. Surveys show that older people, who tend to have less efficient digestive systems, often skimp on these foods. As a result, they, and their immune systems, are deficient in anti-oxidants and other essential micronutrients. Get that right and you’ll live out your years in good shape.

Vegetarians and Vegans

By “vegetarian,” we mean someone who avoids eating animals that have been killed, but consumes other foods of animal origin, such as dairy products and eggs. By “vegan,” we mean someone who avoids foods from any animal source whatsoever. Many vegetarians and vegans make the mistake of simply eliminating animal matter from their normal, “eat anything” diet. As a result, some vegetarians and vegans are obese, have poor complexions, and suffer ill health simply because they are continuing with other bad habits. Notably, this is because they replace the animal food by increased consumption of cereals, bread, pasta, and other complex carbohydrates. There are other errors as well, such as the use of dairy products, lentils, beans, tofu, soy protein, and bad fats and oils.

Vegetarians and vegans will find in the pages of this book exactly the right prescription for eating healthily. All you have to do is eat in accordance with the Savanna Model, ignoring the animal products where they are mentioned, and choose the vegetable alternatives instead.

Veganism can be a healthy lifestyle, provided that you carefully follow the Savanna Model consumption pattern. The secret is to eat like the gorilla, a natural vegan: consume very high volumes of plant material, including nuts, and avoid all the bad foods that do not conform to the Savanna Model diet. Vegans need to worry about the one nutrient that is not available in their diet: vitamin B12. The gorilla makes it in his intestine, but humans do not. (This suggests that veganism is not a natural human eating pattern.) Vegans should take supplements of vitamin B12: it does not require much, just 2 micrograms per day will be enough. Vegetarians, on the other hand, will get all the B12 they need by eating eggs.

Chapter 8

The Savanna Model Lifestyle

We have seen how our ancient environment conditioned our bodies—and our very natures—for life on the savannas of east Africa. We called this lifestyle the “Savanna Model” and outlined how our ancient ancestors fed themselves for thousands of generations. Now, we look at aspects of the Savanna Model lifestyle: physical activity, social well-being, and living arrangements. Our modern lives, in all their aspects, are at variance with the way nature designed us for life. The Bond Effect is learning to live in harmony with the way nature intended. This manner of looking at who we really are elegantly resolves many enigmatic lifestyle questions. It cuts through much humbug to reveal fundamental, if uncomfortable, truths.

PHYSICAL ACTIVITY

Over the millions of years of evolution, what were the patterns of physical activity practiced by our species? What will that tell us about the amount of exercise we should be getting today? Surprisingly, we can work out a lot about the physical activity of our Pleistocene ancestors. We know how they must have foraged for food, how far they traveled, how fast, and even their muscular development. Our study of contemporary forager tribes like the San shows how they organize themselves on a daily basis.

A typical African Pleistocene group would camp in one place for a few days and then move on to make another camp 10 to 20 miles away. They carried very little with them, but they still had to walk all the way. They moved, not for the fun of it, but because they had to. The terrain was open, savanna-type grassland.

While camped each day, the group would split up to forage for food. The women, children, and old men went off in one party, foraging for roots, fruits, tubers, berries, and easily caught bugs and animals. This party on average covered about 5 miles, they leisurely walked and rested from time to time, and after about 4–5 hours they were done. It is estimated that the average adult female energy expenditure on physical activity was 600 kilocalories (kcal) per day. This compares to 230 kcal for today’s sedentary female office worker.

The able-bodied men went off chiefly looking for small game, but would also be collecting other edible matter on an opportunistic basis. This party would cover more ground during the day—9 to 12 miles on average. Part of the time, they would be running or jogging, to chase and trail potential game. Most of the time, they would be finished after about 4–5 hours. Less frequently, they might be away for as much as 48 hours, tracking a wounded animal. It is estimated that their daily expenditure of energy was over 1,000 kcal. Compare this to the 306 kcal of the average sedentary male office worker.

There are therefore two patterns, one for each gender. Females would pass their lives exercising to a moderate extent and with low intensity. Males started their lives with the female pattern, graduated to the male pattern (vigorous and more sustained physical activity) for most of their lives, and then tapered off to lesser levels again in old age.

How does this fit with what we know about human biology today? Evidence is that women do not need to exercise as long or as hard as men to maintain their health. Men need more vigorous physical activity to remain healthy. What happened to our ancestors in old age? What is striking is that old people stayed physically active until their very last days. They were athletes right to the end.

Exercise and Your Health

So, what are we to make of this? Everything we know about individuals who get this amount of physical activity demonstrates that, as a result, they have better health than they would otherwise have had. The big question is, are there any vital body functions that depend on physical activity? Studies, whether on bed-ridden people or on astronauts, all point to a number of conditions brought about by a lack of physical activity.

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Bone Demineralization and Fractures
—The absence of exercise is one of the factors that undermines bone health. Regular physical activity improves bone structure, volume, and its resistance to fracture. Elderly women can benefit from as little as one hour per week of low-intensity activity—a 42% lower risk of hip fracture and 33% lower risk of vertebra fracture.
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The rhythmic jolting associated with walking or jogging excites the bone-building cells (osteoblasts) into raising their tempo. In young people, the bone-builders work faster than the bone-strippers (osteoclasts) and their bone mass increases. Even in older people, the bone-builders will work harder and maintain pace with the bone-strippers.

The Process of Bone Remodeling

Our bones are continuously being broken down and rebuilt. It is estimated that our entire skeleton is completely rebuilt at least three times in a lifetime. Our bones are like a girder bridge whose struts are removed one by one and replaced. There are specialized cells that do the strut-removal called osteoclasts. The cells that put in new struts are called osteoblasts. The process is known as bone remodeling. The cells speed up or slow down in response to stress placed on the bones, various hormonal instructions, and the body’s need for calcium. Trouble occurs when struts are removed but not replaced, leading to osteoporosis. This is a dysfunction caused by many different factors, one of which is the absence of stress (such as physical activity) placed on the bones.

Arthritis and Joint Stiffness—Regular activity of the kind practiced by our Pleistocene ancestors encouraged cartilage maintenance, lubrication, and renewal of the wearing surfaces in joints. Dysfunctional joints are due in large part to not giving them enough to do. It is a cliché, but true: if you don’t use it, you lose it.

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Syndrome X
—Syndrome X is a metabolic disorder that represents a cocktail of “diseases of civilization” that occur simultaneously. The main conditions are high blood pressure, coronary artery disease, obesity, high cholesterol, and diabetes. They all have a common link—high insulin levels. Low exercise levels mean that more insulin has to be secreted to handle a given glucose load. The result is more insulin floating around creating mischief. Exercise is essential to maintaining optimum resistance to diabetes, obesity, hypertension, and heart disease.

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Lower Leg Circulation
—There is an artery that passes through the ball of the foot. As you walk or run, this artery is alternately compressed and released, and the general effect is that of a pump. Walking or running helps pump blood through the lower leg. Without it, the lower leg gets poor circulation and is prone to deep vein thrombosis. Are you one of those people who, after a little while sitting at a desk or table, find their knees jogging up and down? This, too, is a natural reflex helping to maintain lower leg circulation.

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Lymphatic Circulation
—As handmaiden to blood circulation, we have a secondary system of circulation known as the lymphatic system. This is responsible, in part, for transporting the products of digestion to other parts of the body, bringing immune system cells to parts of the body under attack, and flushing away debris and toxic matter. Unlike the blood, which is pumped around the body by the heart, the lymphatic system does not have a pump of its own. It relies on the general flexing of muscles to do the job. Lack of physical activity means sluggish lymphatic circulation and a host of potential maladies.

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Longevity
—Studies on identical twins conducted over many years have demonstrated what many people have long suspected—that physically fit people live longer. In one study, it was found that in any given period, sedentary people were 1.3 times as likely to die as the “occasional” exercisers and nearly twice as likely to die as the “conditioning” exercisers. The figures were the same for both men and women. The use of twins, often brought up apart, was particularly useful: it meant that genetic factors could be eliminated as possible reasons.
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We do not know the effect on longevity if we raised our physical activity to the level of our prehistoric ancestors, but it would no doubt be further improved.

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Stress, Depression, and Mood
—Physical exercise has a beneficial effect on a whole range of hormones that regulate mood. Exercise restores the way the brain chemical serotonin functions, helping to lift depression. Physical activity puts a brake on the production of stress hormones (such as cortisol and adrenaline), which calms feelings of panic and stress and reduces damaging insulin production. Finally, endurance athletes can reach a “high,” where their bodies are producing morphine-like substances, giving them a tremendous feeling of well-being.

Physical activity is not an option but a necessity. Our bodies are shaped by our ancestral environment and their proper functioning relies on a particular kind and amount of exercise. Without it, the rest of the body’s systems cannot work properly.

SOCIAL WELL-BEING AND THE IDEA OF HUMAN NATURE

The way we live our lives today puts us under tremendous psychological pressure. In a great many ways, our savanna-bred natures are not made for modern, industrialized society. In this chapter, we bring forward new ways of thinking about what it means to be human in terms of our social environment. Some of these ideas might seem surprising: rather like going round the back of a Wild West film set and discovering that the saloon is just a plywood facade held up by ropes and stays.

Bear in mind that we are talking about the deep undercurrents in human nature. The purpose of this chapter is to make you aware of our deeply buried instincts. You will see how our choices, often made with the best of intentions, sometimes run counter to these savanna-bred instincts. However, bear in mind that all social interactions are highly complicated affairs: we are constantly balancing a Pandora’s box of conflicting desires, postponed gratification, calculation, and social conformity. The insights in this chapter will help you make better choices within the framework of this rich and challenging context.

The social sciences deal with the social and cultural aspects of human behavior. Regrettably, these sciences were hijacked in the early part of the 20th century by academic theorists such as the German-born American anthropologist Franz Boas. They built on the romantic notions of the 18th-century French philosopher Jean-Jacques Rousseau, who asserted, without any evidence, that man is good by nature but has been corrupted by society and civilization. If only, stated Rousseau, we could return to the state of the “Noble Savage,” we would all live happily ever after. Boas went further and asserted that humans have no inherited instincts, abilities, or feelings. He declared that all humans are born as a “blank slate” and behavior is purely the result of social and cultural conditioning. Thus, we are all born with identical potentials to become anything. In other words, there is no such thing as “human nature.”

We now know that this is quite wrong: humans inherit, with their genes, very deeply programmed desires, feelings, and instincts. They cannot be “conditioned” out of existence. But the social sciences are still riddled with false notions. In consequence, we are under pressure to change our behaviors in ways that social theorists consider desirable. Often, these pressures cut across our savanna-bred natures, causing distress, unhappiness, and ultimately mental illness.