Tasty (20 page)

Like fat, sugar, and starches, salt has become a story of excess. People in developed countries consume ten times more salt than remote tribesmen—and our salt-poor hunter-gather ancestors—raising the risk of cardiovascular disease. Yet food today doesn't taste supersalty—people are conditioned not to notice. This was once a survival strategy: our ancestors would overindulge whenever possible, so they could hold out should salt become scarce. Now it's killing people. Alan Kim Johnson, a behavioral psychologist at the University of Iowa, has studied these cravings and concluded that most of the world is literally addicted to salt.

The body's avid responses to carbohydrates, fat, and salt should have made the plain potato chip the ideal consumer product, or even the only food anyone could ever want. But this appeal has certain biological limits. Humans are omnivores, descended from hunter-gatherers who were in turn descended from scavenging mammals. The taste for novelty, variety, and contrast in food is a powerful and underappreciated force.

French psychologist Jacques Le Magnen discovered its
basic dynamic in the 1950s while studying the nature of hunger. Left blind at thirteen by a bout of encephalitis, Le Magnen compensated with a prodigious memory for scientific facts and data. He made his reputation studying the strange attractive powers of smell: how a nose's sensitivity may vary depending on signals from sex hormones, or just the time of day. Le Magnen then began examining the rhythms of appetite and feeding. He set up equipment to track every drop of drink and crumb of food a rat consumed in the course of a day. Almost immediately, he noticed something odd. Rats fed a single kind of food always stopped eating after a short while. Those who received an assortment of items continued ­indefinitely—and, over time, they gained weight. Some biological quirk was nudging the rats to eat a more diverse diet. Satisfying hunger was not a straightforward matter of consuming sufficient calories.

Human appetites function a lot like those of Le Magnen's rats. Eating any single food, even a delicious one, quickly becomes boring, then intolerable. Some American prisons exploit this effect to punish unruly inmates, serving them a blend of leftovers and basic food items such as rice, potatoes, oatmeal, beans, and carrots baked into a bland, indeterminate gray mass called “the loaf.” It meets all basic nutritional needs, but prisoners universally despise it. The American Civil Liberties Union calls this taste deprivation a form of cruel and unusual punishment, but it seems to work: in one jail in Wisconsin, serving the loaf as punishment slashed the number of fights, assaults, and disorderly conduct incidents.

But give people options, and they'll eat a lot. This is commonly known as the buffet or cafeteria effect. Meals with many courses, and foods with a lot of ingredients and a range of sensations, inspire people to keep eating. In 1980, a
husband-­and-wife team of scientists at Oxford, Edmund and Barbara Rolls, did an experiment in which thirty-two volunteers taste-tested eight different foods: roast beef, chicken, walnuts, chocolate, cookies, raisins, bread, and potatoes. Each volunteer then ate a big helping of one of those foods, and finally, sampled them all again. This time, all of the volunteers gave the food they'd overindulged in a failing grade.

Flavor's deep connections to pleasure drive this phenomenon. The experience of pleasure, at its height during the first few bites, declines as a food is eaten. But eat a different dish, and gratification returns. Rolls and Rolls used electrodes and scans to discern how the brain accomplished this perceptual juggling. As the stomach fills, it sends a series of hormonal “Stop!” signals to areas of the brain that regulate appetite and pleasure. Neurons in these places stop firing. But one location, the orbitofrontal cortex, has neurons that respond to
specific
tastes, smells, and other sensations. It can shut down the pleasure response to one kind of food while keeping it alive for others.

Which is why there's always room for dessert. Main courses usually lack sweets, so even on a full stomach, dessert tastes good. And since the world sugar supply began to relentlessly expand four hundred years ago, elevating dessert to a cooking specialty placed at the end of a meal, habit has ensured hundreds of millions of brains are conditioned to expect and anticipate it.

• • •

Potato chip manufacturers had no knowledge of biology when they began to flavor their products with spices in the 1950s. But gradually, the food industry started to develop its own insights into flavor and appetite. Howard Moskow
itz was a young scientist working at the US Army's Natick Laboratories, about twenty miles west of Boston, when he confronted the military version of the prison loaf in the early 1970s: the “Meal, Combat, Individual” ration. Used to feed troops fighting in Vietnam, the MCI was a modern version of Charles Darwin's meat tin. It consisted of a portable packet of four canned foods—a meat, such as beef or turkey loaf; bread, crackers, and cookies; cheese spread; a dessert; and an accessory pack with salt, pepper, sugar, gum, and cigarettes. Soldiers hated them. The ham and lima beans entrée was so despised it was considered bad luck to call it by name; to some it was known as “ham and motherfuckers.”

Soldiers had become so spoiled by the sensory bombardment of fast food that they disliked even passable military fare—even in foxholes, where there was no alternative. The Natick lab was tasked with fixing this problem. At home, “soldiers were given free food in the commissary or mess, yet they were spending their own money on McDonald's,” Moskowitz said. “The Army worried they were spending money on food that might not be nutritious. How do you make military food attractive to the soldiers?”

As a graduate student in the Harvard department of psychology, Moskowitz had worked in the psychophysics lab, experimenting with the perceptions of sweet and salty solutions. (At one point in the late 1960s, Edwin G. Boring, the progenitor of the mistaken tongue map, then recently retired from teaching, took him to dinner at the Faculty Club and regaled him with psychology stories from decades past.) Moskowitz wanted to study the biology of pleasure, but when he proposed it as a thesis topic, his supervisor told him it would never be taken seriously. A scientist's job was to discover universal, unvarying principles in nature, the adviser declared;
the enjoyment people received from flavor was quirky and variable, a scientific nuisance factor better averaged out of the picture.

At Natick, pleasure was the objective. Moskowitz started to look for ways to manipulate enjoyment. He ran taste tests focusing on sugar. He found a consistent pattern: as concentrations rose from zero, pleasure grew, then leveled off, and finally dropped. This wasn't a new or even a surprising discovery: tiny concentrations of sugar, or anything, are barely detectable, and large ones become overwhelming. But the idea that there was a “just right” point in the middle had never been applied to mixtures of many ingredients, or to foods such as ketchup. A colleague at the lab eyed the peak of one of Moskowitz's pleasure graphs and remarked, “Howard, you have discovered the bliss point.”

Moskowitz began combining ingredients in different proportions and running more taste tests to find the bliss point for each mixture. Some had more than one: pleasure rose, then fell, then rose again as potency increased. Not everybody had the same bliss points, he noticed. There was a kaleidoscopic range of perception and sensitivity. This work helped to shape the improved flavors of the next generation of the military ration, the “Meal, Ready-to-Eat,” or MRE, its courses now sealed in lightweight plastic pouches. But Moskowitz thought he had discovered something that had applications far beyond rations. He pitched his ideas to some food companies. At first, none was interested.

The problem was another old prejudice. “Fundamentally, they thought everybody was pretty much the same,” Moskowitz said. “They realized there were differences from person to person; it was known in the literature since the 1890s. But they said, ‘Those differences, let's sweep them under the rug.
We know people are different, but we don't really know what to do with it.' There were no organizing principles.”

Food companies recognized his qualifications and offered him work as a consultant anyway, and he left the Natick lab. He combined research about bliss points with detailed surveys of flavor preferences, seeking to find the tastiest blends of contrasting ingredients. Certain rich foods were intensely delicious, but the taste became overwhelming. “Can you imagine eating hamburger every day? I think so. White bread? I think so,” he said. “Steak? I don't think so. Duck? Maybe you like it, but can you imagine eating Peking duck every day of your life?” Blander flavors produced by mixes of contrasting ingredients triggered pleasure and gratification without overdoing it. Ketchup, for example, contains liberal doses of umami, sweet, salty, and sour tastes, with pleasant aromatic notes. Potato chips are rich and vivid, but melt away quickly. To target consumers with different preferences, recipes could be formulated several ways.

In 1986, Moskowitz persuaded Maxwell House, which was losing a war for the coffee marketplace to Folgers, to start selling a selection of roasts: weak, medium, and strong. Sales rebounded. He told Campbell's, whose Prego spaghetti sauce had failed to make inroads against dominant Ragu, to make an extra-chunky version. It earned them $600 million. Moskowitz also found that the powerful hedonic spells of sweetness, saltiness, and fat could raise the bliss points of many foods. Companies began spiking products with them. Moskowitz had helped to lay the groundwork for the dazzling, sometimes bewildering, landscape of taste consumers now navigate.

• • •

Flavors bloom from the bottom up: from the fizz of chemical reactions on the tongue and through metabolic signals from the gut. But our over-developed frontal cortices, which handle thinking and decision making, mold them from the top down, too.

The color, appearance, and identity of a food is as impor­tant as any ingredient. Researchers at the Nestlé Research Center in Lausanne, Switzerland, tested this idea. They showed volunteers lying in an fMRI scanner pictures of high-calorie dishes such as pizza and lamb chops, and low-calorie foods such as green beans and watermelon. Volunteers' tongues were stimulated by a small electrode, producing a mild, neutral taste. As they viewed the pictures, their perceptions of this taste changed. The healthy foods got only mild responses. But the brain lit up at the sight of the rich foods, with activity focused around the orbitofrontal cortex. The electric taste instantly became yummy. The results showed that a pleasant taste takes shape as one lays eyes on delicious food: the mere suggestion of pizza tastes good. It's a complicated response that weaves together vision, memory, and knowledge. It's also nearly instantaneous. “These reactions happen within hundredths of a second: these initial representations are activated, and then there is a change from sensation to cognition,” said Johannes le Coutre, the neuroscientist who directs Nestlé's lab. “The visual and gustatory signals integrate with each other.”

Many other cognitive impressions influence flavor, including the weight, shape, and color of bowls and utensils. A light plastic spoon makes yogurt seem denser and more expensive than a heavier one. A blue spoon makes pink yogurt taste saltier. A white spoon improves white yogurt, but makes pink yogurt taste worse. Salty popcorn tastes sweeter in a blue or
red bowl, while sweet popcorn tastes saltier from a blue bowl. The subtle flavors of wine are especially vulnerable to such manipulation. When people are told a wine is more expensive, it tastes better. The color of a wine, indelibly linked to certain flavors, generates the biggest biases. In a 2000 experiment, students from the oenology program at the University of Bordeaux taste-tested a white wine made from semillon and sauvignon blanc grapes, a red mix of cabernet sauvignon and merlot, and finally the white wine again, this time dyed to appear red. They then wrote down their impressions. Their descriptions of the dyed white wine included many flavor descriptors usually used for reds, including “chicory,” “coal,” and “musk.”

Food companies exploit such tricks to nudge consumers' senses and buying habits. Names, colors, and packaging are designed to leap out at shoppers from supermarket shelves, preternaturally forming a taste in the mind. The most powerful of these tools is, by far, the brand. It's an entire set of memories, feelings, and associations organized around a single name and a logo, which the brain accesses each time it's glimpsed.

In 2004, scientists at Baylor University in Houston ran experiments to show exactly how brands make such deep impressions. They studied reactions to Coke and Pepsi. The two colas have similar chemical makeups and flavors, colors, and consistency. In a taste test with no labels, the volunteers rated both about equally delicious. But once the drinks were labeled, Coke won hands down. Labeled Coke also beat unlabeled Coke. The Pepsi brand, meanwhile, did not seem to influence taste: labeled Pepsi scored the same as unlabeled. Next, the volunteers were placed in an fMRI machine, where they prepared to sip sodas pumped through three-foot-long
straws. Before the sip of cola arrived, a screen flashed an image of a Coke or a Pepsi can. Pepsi's performance was again underwhelming. When the Coke can appeared, the hippocampus, the memory hub, came to life before the volunteers sipped. So did an area of the prefrontal cortex tied to conscious perception. The mind appeared to be accessing the vast trove of Coke's cultural associations and setting expectations, bringing experience to bear on flavor.

• • •

As the twenty-first century arrived, food and beverage manufacturers had reached the limits of their ability to manipulate the senses. Every possible trick had been tried. Choices proliferated. Swinging through ancient jungles, our monkey ancestors grabbed at luscious ripe fruits amid the greenery. But what happens when the fruits outnumber the leaves?