100 Million Years of Food (15 page)

The great irony about plant foods is that the more we reduce their harmful by-products and chemical defenses, the more sugarlike they become, and thus the more we increase our risk of acquiring chronic diseases like type 2 diabetes and gout. The ultimate reason for this double-edged character of plant foods is that they are not our original food source; we don't have the specialized digestive systems or teeth that dedicated herbivores like gorillas and cows possess to grind and digest large quantities of unprocessed plant foods, and must make do with a series of ingenious culinary workarounds to render plant foods suitable eating.

But such ingenuity! The staples that we grow up with become enshrined in our hearts, and the plant that has been arguably closest to Westerners' hearts for several millennia has been wheat. In the Lord's Prayer, Christians recite: “Give us this day our daily bread.” Wild wheat was gathered at least as far back as 17,000 BC. The great virtue of wheat is that it contains starch, an easily digestible carbohydrate, and gluten protein, which is sticky and can be leavened with yeast to make bread (rice lacks gluten and therefore makes poor bread); as mentioned, the process of fermenting wheat and turning it into bread reduces harmful oxalate levels.
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However, wheat—and gluten in particular—has become the scorn of a rising movement, blamed for instigating a plethora of diseases. Celiac disease is an autoimmune intestinal disorder triggered by the form of gluten protein found in wheat, barley, rye, and closely related cereals; it currently affects 1 to 2 percent of people in Western countries. The symptoms of celiac disease usually take months or years to develop after exposure to gluten. Children with celiac disease may eventually exhibit anorexia, lack of energy, pale skin, growth retardation, delayed puberty, or rickets, while adults with celiac disease may experience symptoms including diarrhea, nausea, vomiting, stomach pain, flatulence, and weight loss.
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Celiac disease is also prevalent in North Africa, India, and the Middle East. Wheat, barley, and rye have been major food sources for thousands of years in the areas where celiac disease is most common, so why has natural selection not curtailed the frequency of the genes underlying celiac disease?
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One possibility is that the cereals that trigger celiac disease have not been consumed by us for a long enough time for evolution to do its work. According to this argument, the three hundred or so human generations that have been exposed to these cereals were not affected enough by celiac disease for it to have diminished the ability of these people to bear children. The problem with this argument is that celiac disease is a serious disorder and would have harmed a person's reproductive prospects in the days before medical treatment and gluten-free diets were widely available.

An alternative argument is that the genes that promote celiac disease may somehow give people better health in other ways. When scientists scanned gene databases for patterns in celiac disease, they found that some of the genes that lead to celiac disease increased in frequency between 1,200 and 1,700 years ago, just when human dependence on cereals should have pushed the genes to obscurity. The key is that these same genes are also involved in protecting people against bacterial infections. In other words, celiac disease may be a double-edged disorder, which confers bacterial protection but makes bearers of these genes vulnerable to gluten poisoning.
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However, celiac disease is increasing rapidly, and not everyone who has a genetic predisposition toward celiac disease develops it.
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Changing genes cannot be a complete explanation. Something crucial in the environment must have altered as well. Scientists have recently observed that birth via Cesarean section may increase the risk of celiac disease, perhaps due to the lack of transmission of the mother's intestinal bacteria to the baby; overuse of antibiotics may similarly reduce intestinal bacteria and increase the risk of celiac disease.
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Other disorders besides celiac disease have been blamed on the consumption of wheat. For example, wheat allergies have become more prominent (the topic of food allergies will be discussed in a later chapter). Other gluten reactions seem to involve neither autoimmune (as in celiac disease) nor allergic mechanisms and are currently lumped under the label “nonceliac gluten sensitivity,” or more often “gluten sensitivity.” Commonly reported symptoms of gluten sensitivity include headaches, “foggy” states of mind, fatigue, depression, bone or joint pain, muscle cramps, leg numbness, and weight loss. People with gluten sensitivity believe that the symptoms improve when gluten is removed from the diet, but many medical practitioners and doctors are skeptical because clinical experiments have not demonstrated any symptoms from gluten consumption so far. The link with gluten may be a nocebo (i.e., negative placebo) effect, purely in the mind. The perceived problems with eating wheat products may stem from other chemical components that are present alongside gluten; for example, there has been a surge of interest in the study of short-chain sugars (also known as FODMAPs, for fermentable oligo-, di-, and monosaccharides and polyols) that ferment quickly in the intestines, causing bloating, gas, gastroesophageal reflux, and diarrhea, and may be the true cause of gluten sensitivity. FODMAPs are extremely widespread in contemporary Western diets, in the following chemical forms and foods:

•
free fructose
in apples, cherries, mangos, pears, watermelons, asparagus, artichokes, sugar snap peas, honey, and high-fructose corn syrup

•
lactose
in milk, yogurt, ice cream, custard, and soft cheeses

•
fructans
(fructose chains) in peaches, persimmons, watermelons, artichokes, beetroot, Brussels sprouts, garlic, leeks, onions, peas, wheat, rye, barley, pistachios, legumes (beans), lentils, and chickpeas

•
galacto-oligosaccharides
(short chains of galactose sugars) in legumes, chickpeas, and lentils

•
polyols
(sugar alcohols) in apples, apricots, pears, avocados, blackberries, cherries, nectarines, plums, prunes, cauliflower, mushrooms, and snow peas
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Intestinal discomfort may therefore result not simply from eating too much wheat (or gluten) but rather from eating too many sugary foods, including factory-made sweetened breads as well as fruits and fructose-containing foods. Like celiac disease, FODMAPs may lead to intestinal discomfort when intestinal bacteria populations are altered through the overuse of antibiotics. Another consideration is that moderate exercise can help to reduce gastrointestinal disorders such as irritable bowel syndrome and constipation, whereas too much vigorous exercise can exacerbate gastrointestinal disorders like reflux, heartburn, diarrhea, and gastrointestinal bleeding.
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Overall, plant foods are best prepared and eaten in traditional ways—grated, steamed, roasted, fermented, and so on—rather than served raw, and complemented by a lot of moderate exercise like walking and the avoidance of particularly sugary foods, which will help alleviate intestinal discomfort from FODMAPS-induced gas.

*   *   *

When I first arrive in China, I eagerly try the street food in the student ghettos surrounding Bengbu College, but the fare—wheat wraps, vermicelli soups, barbecue skewers—is disappointingly oily and spicy. I know there must be better food out there, but the students generally can't afford to eat off campus, and I don't speak enough Mandarin to befriend the teachers who can't speak English. As a result, I spend most of my evenings at the track, trying to jog while weaving around chatting students and families, or at the gym, playing basketball, badminton, table tennis, and volleyball with students and teachers. After Christmas, the English Department desperately needs volleyball players to help trounce the Nutrition Department, the latest incarnation of the annual teachers' competition. Although I am technically a member of the International Relations Department, I had played setter and captain on my high school's junior volleyball team, so through bureaucratic sleight of hand, I become a bona fide member of the English Department. It's going to be a big match, I'm told over and over by jittery colleagues. The day of the big game, I get psyched and participate in a super-vigorous warm-up session. Unfortunately, I have been experimenting with low-glycemic diets of barley, oats, millet, beans, and other indigestible food and warm up so hard and have been out of volleyball for such a long time that I am famished and exhausted by the time the game starts. As the students crowd the sidelines and yell out coordinated cheers, I fan at the ball a few times and botch some easy sets. We squander the big match. My colleagues are crushed. However, I am told there will be another set of games the next day, a chance for possible redemption.

Before heading to the match the following afternoon, I pull out a frozen banana from the freezer and microwave it to a steaming calorie-rich mush and pop an obsidian-black “thousand-year” cured and salted duck egg in my mouth. I bound to the gym like a 150-pound Vietnamese version of the Incredible Hulk. The English Department students have mostly given up on us and gone home for the long-weekend holiday, but I pound the ball and scream as if it's an Olympic showdown. After losing our first match, we win our second match against the Biology Department, salvaging pride and second place overall. The English Department has secured its reputation for another year.

I am invited to a celebratory banquet at a fancy restaurant in Bengbu. Cigarettes are passed around, hard liquor poured out. This evening is about slapping backs, shaking hands, pouring drinks for senior colleagues, making toasts—all the schmoozing needed to smooth out office politics for the upcoming months. I am toasted for my efforts on the volleyball court, but my attention is riveted by the platters of food being slowly spun around the table: honeyed slices of lotus, crispy fried carp, tender marinated beef quivering with fat, savory pork ribs, a mob of other delicacies, every dish a winner. My salary at the college is $800 a month, of which $400 is siphoned off to service my student loans, which makes me poor even by Chinese standards. I'll never see the likes of this food again. I'm feted with rice wine until my head can barely stay level, but like a man just rescued from weeks of being stranded in the desert, I continue to obsessively pick at the remnants of the dishes while the teachers fervently schmooze.

Sumptuous meaty feasts like this are a rarity in China. When two of my students invite me to visit their homes, two-story concrete dwellings set in sparsely forested countryside, some gamey chicken and bits of pork are served, but the mainstays on the table are tofu, eggs, peas, tomatoes, peanuts, and greens, fried in lard or, increasingly, vegetable oils, and, of course, white rice, with green tea or rice wine. Due to the lack of red meat and dairy, this type of cuisine is likely to delay the onset of chronic diseases like breast and prostate cancer, but the oily sautéed greens and white rice are likely risk factors for obesity and diabetes, respectively. When my students ask me what I think of Chinese cuisine, I tell them I like traditional Chinese cuisine, when lard was used to lightly sauté vegetables, rice was hand-milled and accompanied by yams or grains like barley, and insects, fish, and frogs supplemented the meat. Unfortunately, such food is quickly becoming a distant memory. Now a bullet train thunders through the countryside around Bengbu, cars, tractors, and motorcycles have replaced walking, old-fashioned lard has been replaced with cheap vegetable oils like soybean and corn oil, rising incomes are used to purchase meat and milk, and the rice is white as snow. In a country obsessed with modernizing, it will take another generation before Chinese people realize how damaging to health these dietary and lifestyle changes have been. Then the Chinese will start to look back to the ways that their ancestors once lived and ate.

 

ELIXIRS

Many children are not consuming recommended servings of dairy foods.… Dairy foods provide essential nutrients needed for body maintenance and protection against major chronic diseases.

—
G
REGORY
D
.
M
ILLER,
J
UDITH
K
.
J
ARVIS, AND
L
OIS
D
.
M
C
B
EAN,
Handbook of Dairy Foods and Nutrition

Cow's milk consumption is a major health hazard and should be recognized as a promoter of most common chronic diseases of industrialized countries.

—
B
ODO
C
.
M
ELNIK,
“Milk—The Promoter of Chronic Western Diseases”

Three liquids have had an enormous impact on human health over thousands of years: water, alcohol, and milk. Tea and coffee have also been important beverages in parts of the world, particularly in terms of their economic impact in recent centuries, but because scientists are still largely unclear about the long-term health effects of drinking tea or coffee, we won't delve deeply into these beverages. I've had long discussions with friends about the mood swings associated with coffee/caffeine dependence, but given the extreme irritability such discussions engender (especially as the time since the last caffeine hit drags on), I've learned not to frown or roll my eyes as my friends fork over their cash to the coffeehouse giants. In any case, according to one recent large American survey (more than 250,000 men and more than 170,000 women between the ages of fifty and seventy-one), drinking six cups of coffee or more a day lowers the risk of dying by 10 percent (men) or 15 percent (women); so perhaps my coffee-addicted friends have justification for frowning and rolling their eyes at
me.
The most obvious explanation for why drinking coffee cuts the risk of death is that the alertness accompanying caffeine consumption decreases the chance of getting into a fatal accident, but coffee drinkers also seem to have better chances of avoiding heart disease, respiratory disease, stroke, diabetes, and infections, which suggests that some other compound in coffee besides caffeine (like polyphenol antioxidants) might confer health benefits. Similar reductions in mortality have been obtained in Japanese studies on coffee drinking. Scientists haven't noted any similarly substantial health benefits from drinking tea so far.
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