100 Million Years of Food (13 page)

The English naturalist Charles Darwin was no poet, but he viewed the natural world with a clarity that was extraordinary for his time, and he captured the dilemma of eating vegetables exquisitely in these (for him, impassioned) lines: “what war … between insects, snails, and other animals with birds and beasts of prey—all striving to increase, and all feeding on each other or on the trees or their seeds and seedlings…!” In other words, eating plant foods is an act of war, every head of broccoli laid out on the cutting board a decapitation. Our crops are slaves to our hunger; farmer's fields are prisons for thousands and millions of speechless, immobile inmates. I'm not saying this to turn your seven-year-old daughter off veggies forever; I'm saying this because it clarifies why George H. W. Bush and many other people don't like many vegetables, including broccoli. The humorist Roy Blount Jr. conveyed the sentiment in a memorable couplet: “The local groceries are all out of broccoli / Loccoli.”
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Plants may be immobile, but they're far from defenseless.

It's true that many plants have medicinal properties, but this does not make them healthy everyday fare. If plants comprised the bulk of traditional diets, this was partly out of sheer necessity—many large mammals went extinct, and the remaining large animals were difficult to catch, time-consuming to raise, or expensive to purchase—and partly because people learned how to cook vegetables in a way that created a satisfying meal, which is to say, in a way that neutralized the most valiant defenses that a plant could muster against a predator like ourselves.

The goal of this chapter is to analyze the complex history between plants and humans. We'll parse common plants into various categories based on the kind of harm or benefit they confer to us and discuss how humans have evolved, biologically and culturally, to eat plant foods. The overall message: Like most other foods, plants have no nutritional significance on their own; what matters is the overall composition of the meal, the way the food is prepared and cooked, the environmental context, and the genetic ancestry of the eaters.

China is a worthwhile place to consider the question of plant foods, because thousands of years of rice cultivation and high population density mean that animal foods there are relatively scarce and plants foods are paramount.

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I apply for an English-teaching job in China through an employment agency and receive the green light. Now I'm looking out through dust-caked windows at a gray sky. The college lies at the easternmost edge of a low-slung manufacturing city, Bengbu, formerly renowned as a center for pearl production. Out here at the college, dusty pavement gives way to dirt roads. Clouds of grime billow from trucks ferrying open loads of dirt and gravel. The rear of the school property is demarcated by an oily black waterway, from which water is drawn to feed a patchwork of rice fields. A stand of skinny trees shivers next to the construction road, surrounded by a pile of discarded fertilizer and pesticide bottles and plastic packages. Behind the teachers' apartments, elderly folks hoe, water, and weed plots of cabbage, beans, corn, rapeseed. On the other side of the black canal, tractors grind over the rice plots. Plumes of sooty smoke from smoldering rice stalks smudge the horizon, the acrid odor permeating the air.

When I ask my students what they consider to be China's greatest problem, the answer is nearly unanimous: too many people. I encounter this problem even in the school, where I struggle to remember the names of three hundred students. One girl icily remarks, “You've asked my name three times today.” It's debatable whether a large population is a hindrance or a boon in terms of economic development—prosperous East Asian economies in Japan, South Korea, and Taiwan are backed by some of the highest population densities in the world—but the crowds of China are definitely overwhelming. For relief from the noise and suffocating press of people in the city and around campus, I head out to the hills behind the college, beyond the rice fields, hiking by myself or with students. Mostly, though, the crowds are unavoidable. My students complain to me that Bengbu is a small town; with a million inhabitants, Bengbu ranks a paltry 182nd in urban population among Chinese cities, a mere backwater in this teeming nation.

One of the consequences of China's staggering population density is that meat is largely absent from diets because limited land is available to raise animals and wild game is relatively scarce. Hardly any of my students or teacher colleagues buy meat, partly because it's considered unhealthy, but mostly because it's expensive. When my Chinese students and colleagues taste meat, it's chiefly nibbles or soup bones for flavoring. Most of their calories come from vegetables and, especially, rice or wheat flour in the form of noodles, along with generous helpings of vegetable oils and sugary junk food.

The topic of food weighs heavily on my students' minds. Some of them profess that given a million dollars, they would travel around the world to eat delicious foods or head to Beijing and gorge on Peking duck. To see the way their eyes sparkle like Christmas lights at the mention of Peking duck! In South Korea, people were often categorized on the basis of whether they liked mountains or the sea. In Bengbu, the critical question is: Do you like to eat rice or wheat?

Sidney Mintz, a food anthropologist at Johns Hopkins University, has pointed out that eating unadorned starches is no simple thing. Try downing multiple bowls of white rice, or several boiled potatoes, or a plate of pasta without tomato sauce—it is very difficult for us to eat and digest large quantities of plain starches. Compare that to the ease of sinking your teeth into grilled chicken with a crisp layer of golden skin or a T-bone steak oozing juices. Professor Mintz argues that poor people around the world have historically been relegated to eating flavorless starchy foods, which were made palatable only through the addition of fringe dishes: Think of a thick swirl of spaghetti in a lake of tomato sauce; chilies kicking up corn and beans; or rice with soy sauce, fish sauce, or pickled vegetables.
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The elites of society, meanwhile, dispensed with the whole business of bland cores and flavorful fringes and helped themselves to meats that were furnished by the laboring masses.

Nor have things changed much; during graduate studies in Los Angeles, I used to pedal my rickety bicycle through Beverly Hills, peering through restaurant windows at elegant people dining on steak, caviar, and sushi, while a pound or so of brown rice—garnished with soy sauce, to be sure—made steady but unspectacular progress through my intestines like a dump truck backing up in a narrow alley.

During this period, I experienced moderate but consistent pain in my lower abdomen area. I had to wake up to use the bathroom at the same time every night. I went to the university health clinic to get an assessment. I didn't have high hopes, since the doctors and nurses there had been previously baffled by my symptoms. However, the pain was affecting my ability to concentrate, and I was worried that it augured something serious.

The nurse whom I saw wasn't too worried. “Look,” he said soothingly, like a parent plastering a Band-Aid over a child's scraped knee, “the urge to urinate at night is perfectly normal. It's very common. I have to get up every night myself.”

But I didn't have any of these symptoms a year ago. Maybe the problem was related to my bike seat. No, the pain continued when I stopped riding. At the time, I was famous among my colleagues for bringing lunch boxes that were packed with brown rice. A few months after the visit to the clinic, I dropped by my parents' home in Canada and learned that they, too, experienced discomfort from eating brown rice; in fact, they had stopped eating it. Within days of going off brown rice, my pain disappeared. I crowed triumphantly to my mother, “That was it! I don't have to go to the bathroom every night anymore. It was the brown rice!”

The pain was likely aggravated by hernias incurred while struggling with heavy (for me) weights in the gym, trying to add some Schwarzenegger-like bulk to my toothpick frame—when you hit the beach in L.A., you couldn't afford to look like some anemic geek who spent all his time in a cubicle turning textbook pages. Yes, I should have soaked the brown rice for a few hours before cooking, which would have made the rice softer and easier to digest, but as a grad student with a dissertation to complete, it was taxing to remember my name, let alone remember to soak the brown rice.

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Considering the blandness of starchy foods and the difficulty of digesting them leads to one of the most important questions concerning the history of humanity: Why did humans give up hunting and gathering for sedentary agricultural life? After all, hunting and gathering appears to be much more rewarding than the backbreaking labor of a farmer. On top of that, the hunter-gatherer gets a pretty good meal out of wild game and assorted veggies, fruits, and nuts, while the farmer gets … well, a lot of starch that needs to be doused with salt, sugar, oil, or spice to make it palatable.

The transition from mobile hunting and gathering to sedentary agriculture took place in thirteen to twenty-four different locations around the planet, starting around twelve thousand years ago, and proceeded in fits and starts for several thousand years. Many explanations have been proposed, but none have gained widespread acceptance among archaeologists or other researchers. One theory holds that hunter-gatherer populations expanded and created strain on local food supplies until it was necessary to give up the leisurely life of the hunter-gatherer for the nutritional deficiency and toil of farming life. Another major set of theories focuses on climate change. Around twelve thousand years ago, the climate ceased to fluctuate and became cooler and drier, and more atmospheric carbon dioxide was available, which could have made growing crops feasible for the first time.
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However, it turns out that some societies increased in population only after they took up agriculture, or switched to farming while their populations were declining. Moreover, early agriculture seems to have occurred in areas that had plentiful food, rather than food scarcity.
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Another possibility relates to the fact that humans cannot consume more than 35 percent to 40 percent of calories in the form of protein, due to the accumulation of toxic levels of ammonia and urea as by-products of digesting and metabolizing protein. Although protein must be consumed, fat and/or carbohydrates must provide the bulk of calories. The end of the last ice age twelve thousand years ago caused forests to take over grasslands and thus created habitat stress on large mammal populations, but humans hungry for fatty meat certainly also helped the megafauna to their demise. Moreover, the appetite of the hunters for fatty meat guaranteed that no new large mammals evolved to take the place of the extinct megafauna. After humans migrated from Africa and entered Australia, New Zealand, Tasmania, North and South America, Madagascar, Japan, and other landmasses, the lumbering feasts of meat—giant marsupials, giant deer, giant flightless elephant birds, giant lemurs, giant beavers, and more game—were the first to go extinct, followed by their smaller, more nimble, and less fatty relations. Large mammals were sometimes able to survive in dense forests (like those in the Amazon and Southeast Asia) or the coldest, most forbidding regions of the world, such as the New World Arctic. Big game also persevered in Africa; due to the long history of coevolution with bipedal (walking upright on two feet) hunters on the continent, animals may have evolved to be wary enough to survive Neolithic weaponry.
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As climate change and hunting pushed the great mammals, lizards, and flightless birds to extinction, hunter-gatherer groups could compensate for the loss of animal fat by subsisting on leaner game animals. For example, in Southwest Asia, large game like wild cattle, deer, and wild boar steadily disappeared from diets starting around thirteen thousand years ago, replaced with smaller animals like mountain gazelles, tortoises, hare, and partridge. Not only did people make use of progressively smaller and leaner animal species, but they also resorted to catching younger gazelle and intensively harvesting gazelle marrow, as well as collecting grass seeds.
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Some groups in Southwest Asia became more sedentary as they hunted out their big game, but others may have become more mobile in an increasingly desperate attempt to get more.
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Thus the critical factor behind the transition to agriculture may have been the loss of big fatty prey. (Insects can also be fatty, but they take more effort to gather per calorie attained, and their chitin exoskeletons may also present problems, as discussed earlier.) Frustration with increasingly lean diets could have led to the adoption of sedentary agriculture and domestication of animals as a last resort. People's health was compromised by the new diet: Diminution in height and the appearance of dental cavities have been noted in the remains of post-agricultural-revolution peoples.
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But that wasn't the worst case. If suitable plants and animals were unavailable, the increase in human population was checked, forcing tribes to live or starve according to the availability of fluctuating food supplies, until migrants from other regions introduced novel domesticated animals or plants.

Plant foods are today heralded as healthy fare, but people in traditional societies generally did not favor them, and for good reason. Consider the fate of the infamous Burke and Wills expedition, a scientific caravan that departed Melbourne in 1860 with the intent of exploring and crossing the Australian interior. The retinue boasted food sufficient for two years and sixty gallons of rum (to revive the camels)—all told, about twenty tons of supplies. However, after several months of mishaps and errors of judgment, three men—Robert O'Hara Burke, an Irish soldier and police officer; his second-in-command, William John Wills, a young English surveyor; and John King, an Irish soldier—found themselves stranded at Cooper Creek, hundreds of miles from Melbourne, with no pack animals (some of the camels had been eaten) and dwindling food supplies. Suffering from malnourishment and exhausted, the three men traded their sugar with native Aborigines for fish, beans, and the spore-like fruit of the nardoo fern. The Aborigines ground nardoo to make a paste and bread that were valuable during drought conditions, but the explorers may have neglected to roast, sluice, or winnow the spores as the Aborigines did. Doing so would have purged the nardoo of thiaminase, an enzyme that destroys vitamin B
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. A person lacking vitamin B
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is debilitated by beriberi, a condition characterized by paralysis, weight loss, and loss of feeling in the extremities. Even though the men were able to consume four pounds of nardoo a day, they steadily lost strength. After weeks of wasting away, Burke and Wills died at Cooper Creek; a rescue party eventually recovered a seriously weakened King.
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