Cooked: A Natural History of Transformation

by Michael Pollan

  The quest for an ever-whiter shade of bread, which goes all the way back to the Greeks and Romans, is a parable about the folly of human ingenuity—about how our species can sometimes be too smart for its own good. After figuring out an ingenious system for transforming an all but nutritionally worthless grass into a wholesome food, humanity pushed on intrepidly until it had figured out a way to make that food all but nutritionally worthless yet again!

  Here in miniature, I realized, is the whole checkered history of “food processing.” Our species’ discovery and development of cooking (in the broadest sense of the word) gave us a handful of ingenious technologies for rendering plants and animals more nutritious and unlocking calories unavailable to other creatures. But there eventually came a moment when, propelled by the logic of human desire and technological progress, we began to overprocess certain foods in such a way as to actually render them detrimental to our health and well-being. What had been a highly adaptive set of techniques that contributed substantially to our success as a species turned into a maladaptive one—contributing to disease and general ill health and now actually threatening to shorten human lives. When and where did we pass over, from processing food to make it healthier to making it less so? To what might be thought of as “overcooking”? There are a couple of places we could reasonably draw that line. The refining of pure sugar from cane or beets would certainly be one. But perhaps the sharpest and clearest line would be the advent of pure white flour (and the bread made from it) in the second half of the nineteenth century.

  The prestige of white flour is ancient and has several sources, some practical, others sentimental. Whiteness has always symbolized cleanness, and especially at times when disease has been rife and food frequently contaminated, the whiteness of flour symbolized its purity. I say “symbolized” because for most of history it was no guarantee: Unscrupulous millers routinely whitened their flour by adulterating it with everything from alum and chalk to pulverized bone. (For centuries both millers and bakers have been regarded with suspicion, often with good reason. It has always been hard to determine what exactly is in a bag of flour or a loaf of bread, and easy to pass off ingredients that are cheaper and less wholesome than wheat flour. This is why, during periods of hunger and political ferment, millers and bakers were frequent targets of popular wrath, occasionally put in the stocks and pelted with bad bread.)

  Adulterated or not, however, white (or whitish) flour was generally regarded as healthier than whole grain well into the nineteenth century. “Coarse flour”—wheat that had simply been ground on a stone and never sifted—was coarse indeed, and gradually ground down the teeth of the people who had no choice but to eat the dark bread made from it. Sifted flour was also thought to be easier and swifter to digest, and certainly for people struggling to obtain enough calories, white bread was a superior source of quick energy. It was also easier to chew, no small thing before modern dentistry.

  So the rich demanded the whitest possible flour, and the poor were left to eat “kaka,” as the French sometimes called brown bread. Going back to ancient Rome, the shade of the bread you could afford precisely indicated your social standing; to know one’s place, Juvenal wrote, is “to know the color of one’s bread.” Some historians and anthropologists have suggested that the prestige of white flour might also have had a racist tint to it. Maybe. And yet white rice has enjoyed a similar prestige in Asia, among nonwhites, so maybe not.

  Whitish flour, which before roller mills could only be obtained by sifting flour through progressively finer meshes of cloth, had a lot to recommend it. Bran tends to be bitter, so the whiter the flour the sweeter the bread. White flour also made for a much airier loaf; even the microscopic shards of milled bran are sharp, and, like millions of tiny knives, they can pierce the strands of gluten in dough, impairing its ability to hold air and rise. (On the same principle, some gardeners kill slugs by spreading wheat bran in their path.) Those tiny bran knives are relatively heavy, too, making it more difficult to leaven a whole-grain loaf. Even at its best, it will never achieve the exaltation of a loaf made with white flour.

  As a solution to these problems, sifting coarse flour was less than ideal. The multistep process was time consuming and expensive. It also failed to address what is perhaps the most serious rap against whole-grain flours: their relatively short shelf life. Whole-grain flour tends to go “off” within several weeks of being milled, releasing an unmistakable odor of rancidity. Part of what makes the germ so nutritious—its unsaturated omega-3 fats—also makes it unstable, and prone to oxidization. Sifting might whiten stone-ground flour, but it could not remove the perishable germ, which meant that flour had to be milled frequently and locally. This is why every town used to have its own mill.

  The advent of roller milling in the middle of the nineteenth century made white flour cheap, stable, and whiter than it had ever been. For a revolutionary technology, roller milling seems almost obvious, and benign. The new mills replaced the old millstones with a sequence of steel or porcelain drums arranged in pairs, each subsequent pair calibrated to have a narrower space between them than the previous set, in order to grind the flour ever more finely. To begin, the seed is dropped between a pair of corrugated drums rotating in opposite directions. During the “first break,” the bran and germ are sheared from the endosperm. Those parts are sifted out before the now naked endosperm moves on to the next pair of slightly more closely spaced rollers, and so on, until the starch (or “farina”) has been pulverized to the desired degree of fineness.

  The new technology was greeted as a boon to humankind, and so at first it seemed. Bread became whiter and airier and cheaper than ever. Commercial yeast performed particularly well with the new flour, vastly speeding and simplifying the work of baking. The shelf life of flour, now that the unstable embryo had been eliminated, became indefinite, allowing the milling industry to consolidate. Thousands of local stone mills closed, since big industrial operations could now supply whole nations. Cheap, stable, transportable white flour made it possible to export flour around the world and to feed swelling urban populations during the industrial revolution. According to one history of bread,* the advantages of white bread were something on which both workers and employers could agree: Brown breads high in fiber “meant that workers had to leave their machines frequently to go to the lavatory, and this disrupted production.”

  Indeed, in many ways, white flour not only gratified human desires but also meshed especially well with the logic of industrial capitalism. No longer a living, perishable thing, flour now became a stable, predictable, and flexible commodity, making not only the production of bread faster and more efficient, but also its consumption. In effect, roller mills “sped up” wheat as a food, making it possible for the human body to absorb its energy much more readily than before. Flour, and bread in turn, became more like fuel and, at least calorically, more efficient. In the jargon of modern nutrition science, bread became more “energy dense,” which, along with extended shelf life, is one of the most common outcomes of modern food processing. Not surprisingly, white flour proved enormously popular with a species hardwired by natural selection to favor sweet foods. The taste of sweetness, which signals a particularly rich source of energy, had always been rare and hard to find in nature (ripe fruit, honey), but with the industrial refining of certain cultivated grasses (wheat, cane, corn), it now became cheap and ubiquitous, with what would turn out to be unfortunate consequences for human health.

  More than just a new food product, white flour helped usher in a new food system, one that would extend all the way from the field to the loaf of presliced and fortified white bread, which now could be manufactured on an assembly line in
three or four hours without ever being touched by human hands. The wheat plant changed, too. The new roller mills worked best with hard-kerneled red wheat; the big, tough bran coat on this type of wheat could be sheared cleanly and completely from the endosperm, whereas softer white wheat left infinitesimal specks of bran in the flour. So, over time, breeding changed the plant to better suit the new machine. But because hard wheat has tougher, bitterer bran, it made whole-grain flour even coarser and bitterer than it had been before—one of several ways that the triumph of white flour made whole wheat less good. Even today, breeders continue to select for ever-harder wheats with ever-whiter—and therefore less nutritious—endosperms. As Steve Jones, the former wheat breeder for the State of Washington, told me, “Wheat breeders are selecting against health.”

  Ah yes, health. Here was the fly in the ointment. The compelling industrial logic of white flour meshed beautifully with everything except human biology. Not long after roller mills became widespread in the 1880s, alarming rates of nutritional deficiency and chronic disease began cropping up in populations that relied on the new white flour. Around the turn of the century, a group of French and British doctors and medical experts began searching for the causes of what they dubbed “the Western diseases” (heart disease, stroke, diabetes, and several disorders of the digestive tract, including cancer), so called because they were virtually unheard of in places where people hadn’t switched to modern diets containing large amounts of refined sugar and white flour. These medical men, many of them posted to Britain’s colonies in Asia and Africa, had observed that, soon after white flour and sugar arrived in places where previously what one of them (Robert McCarrison) called “the unsophisticated foods of Nature” had been the norm, the Western diseases would predictably appear. Some of these doctors blamed the lack of fiber in the Western diet, others the surfeit of refined carbohydrates, and still others the lack of vitamins. But whatever the culprit nutrient or the precise mechanism by which it operated, these men were convinced of a link between processed white flour and sugar and the panoply of new chronic diseases. A large body of contemporary research suggests they were right.

  What to do? Certainly not return to the “unsophisticated foods of Nature”—no one wanted to do that! And yet, by the end of the nineteenth century, several voices were raised in support of just such a course, including a return to whole-grain flour. “The true staff of life is wholemeal bread,” declared Thomas Allinson, a prominent English physician, and one of the first to link refined carbohydrates to disease. To counter the scourge of white flour, in 1892 he bought a stone grinding mill and began baking and selling whole-grain bread under the slogan “health without medicine.” (He was also involved in a group called the Bread and Food Reform League.) Earlier in the century, the American minister and nutritional reformer Sylvester Graham, eponym of the whole-grain cracker, had published an influential Treatise on Bread and Bread-Making that blamed white flour for many, if not quite all, of the ills of modern life, including constipation (a nineteenth-century scourge), and fervently extolled the virtues of coarse dark breads high in fiber. To remove the precious health-giving fraction of bran from wheat was to “put asunder what God had joined together”—a fall from dietary grace for which modern man was paying with his troubled, sluggish digestion.

  By the early decades of the twentieth century, public health authorities in England and the United States could no longer ignore the links between refined white flour and widespread nutritional deficiencies, including beriberi, as well as increases in the rates of both heart disease and diabetes. (It was noted that during both world wars, when the British government had mandated a higher fiber content in flour as part of food rationing, people’s health improved and rates of type 2 diabetes declined.) But by now the White Flour Industrial Complex was so well entrenched that a shift back to whole-grain flour was never seriously contemplated.

  Instead, the milling industry and government came up with a clever technological fix: A handful of the vitamins that modern milling had removed from bread would now be put back in. So in the early 1940s, in what was called “the quiet miracle,” the U.S. government worked with baking companies—including the Continental Baking Company, makers of Wonder Bread—to develop and promote a white bread fortified with a handful of B vitamins. Here was a classic capitalist “solution.” Rather than go back to address a problem at its source—the processing of key nutrients out of wheat—the industry set about processing the product even more. This was sheer brilliance: The milling industry could now sell the problem and the solution in one neat package.

  But fortifying white flour with the missing vitamins represents only a partial, reductionist solution to what turns out to be a much more complex problem. By now the nutritional superiority of whole grains over even fortified white flour is universally acknowledged—yet still only imperfectly understood. People who eat lots of whole-grain foods significantly reduce their risk of all chronic diseases; they also weigh less and live longer than people who don’t. This much we know from the epidemiology.* But why, exactly? Is it, as Sylvester Graham believed, the benefits of dietary fiber? And if so, is it the fiber itself, or the various phytochemicals that typically accompany fiber? Or maybe it’s the vitamins, not all of which are put back when flour is fortified. It could also be the minerals in the bran. Or the omega-3 fatty acids in the germ. Or it could be the antioxidants found in the “aleurone layer,” the innermost layer of the bran. Scientists still can’t say for sure.

  But here is the most curious fact: People whose diets contain adequate amounts of all these good nutrients from sources other than whole grains (from supplements, say, or other foods) aren’t nearly as healthy as people who simply eat lots of whole grains. According to a 2003 study by David Jacobs and Lyn Steffen,* epidemiologists at the University of Minnesota, the health benefits of whole grains cannot be completely explained in terms of the nutrients we know those grains contain: the dietary fiber, vitamin E, folic acid, phytic acid, iron, zinc, manganese, and magnesium. Either there are synergies at work among these nutrients, or there is some X-factor in whole grains that scientists have yet to identify. We are talking, after all, about a seed: a package that contains everything needed to create a new life. Such a recipe still exceeds science’s powers of comprehension and technology’s powers of creation.

  The fact that a whole food might actually be more than the sum of its nutrient parts, such that those parts are probably best not “put asunder,” poses a stiff challenge to food processors. They have always assumed they understood biology well enough to improve on the “unsophisticated foods of Nature,” by taking them apart and then putting them back together again. The industry would be more than happy to sell us bread fortified with any one (or twelve or one hundred) of these nutrients if science could just tell it which ones to focus on. But, so far at least, science can’t reduce this complexity to a simple answer.

  This has been good news for the food itself: Whole-grain bread has been enjoying something of a renaissance. Actually, that renaissance got a first, false start during the 1960s, when the counterculture, steeped in romantic ideas about “natural food,” seized on white bread as a symbol of all that was wrong with modern civilization. Brown bread, being less processed than white, was clearly what nature intended us to eat. They probably should have stopped there, but did not, alas. Baking and eating brown bread also became a political act: a way to express one’s solidarity with the world’s brown peoples (seriously), and to protest the “white bread” values of one’s parents, who likely served Wonder Bread at home. These ideals resulted in the production of some uncompromising and notably bricklike loaves of dark, seedy bread, which probably set back the r
evival of whole-grain baking a generation. “That hippie texture” is a cross that whole-grain bakers still bear today, along with the widespread belief that whole-grain bread promises rather more nutritional and ideological rigor than eating pleasure.

  But whole-grain bread seems to be recovering from its sixties revival and is currently enjoying a reversal of fortune, or at least prestige, with white bread, in a sort of carnival of traditional bread values. Now it is the well-to-do who want brown bread, while white bread is becoming déclassé. The public has gotten the news about the health benefits of whole grain. The government’s latest nutritional guidelines recommend that at least half of one’s daily calories from grain come in the form of whole grains. When you consider that even today only 5 percent of wheat is milled into whole-grain flour, this becomes a challenging recommendation to follow.

  America’s expanding tribe of artisanal bakers, who started out in the 1990s as Francophiles devoted to the white-flour baguette, has begun to take a strong interest in baking with whole grains. Chad Robertson’s next book will take up whole-grain baking, and much of his energies are now devoted to research and development of whole-grain recipes. Craig Ponsford, the former chairman of the board of directors for the Bread Bakers Guild of America and the first American ever to win a first prize in the Coupe du Monde de la Boulangerie baking competition in France, now bakes exclusively with whole-grain flours, and is outspoken about their benefits. (He told me he could never have promoted whole grains at the Guild without offending its milling- and yeast-industry sponsors, so after his conversion he chose to step down.) The supermarket shelves are stuffed with breads and other products making whole-grain claims, some of them more meaningful than others.*