The revolution in molecular biology allows scientists to identify which proteins, in which receptors, send which signals to the brain. Only 1 receptor can identify sweet, for instance, but more than 20 receptors detect tastes that are bitter. “With the sequencing of the human genome,” says Dr. Ray Salemme, Red-point Bio’s CEO, “people have begun to understand, on the molecular level, much of the machinery associated with taste. Chefs have known this instinctually for generations, but now we’re beginning to understand what’s really going on.”
“Taste is like a chair with four legs,” explains Acree. “Before, we only had one leg—flavor chemistry. Now we’re building the other three: how a chemical reacts with the receptor; how that receptor communicates with the brain; and how the brain processes that information into behavior.” Once scientists have identified the chain of messages each chemical sends to the brain, they can begin to manipulate that conversation. The chemical gustducin, for example, is part of the signaling mechanism between receptor and brain. If you remove gustducin from mice, they drink bitter liquids as if they were water. If researchers can find less-invasive ways to stop taste receptors from telling the human brain, “Hey, this food is bitter,” suddenly those Brussels sprouts go down a lot easier. As does a child’s medicine.
But these breakthroughs have uncovered challenges for food conglomerates, restaurant chefs, and home cooks alike: Each of us tastes differently. Though all humans have the same number of receptors, how the brain interprets what those receptors transmit can be radically different, even from family member to family member. Linda Bartoshuk, at Yale’s School of Medicine, and other researchers have known since the 1990s that some people are “supertasters”: They experience many tastes with more intensity—sugar is sweeter, Brussels sprouts more bitter, chiles hotter—than do “nontasters,” who can, for example, tolerate spicy foods more easily. Although there are some evolutionary advantages to such distinctions (supertasters tend to dislike plants with higher degrees of toxicity), there are also disadvantages: When thin, supertasters tend to be very thin, and when obese, they tend to be very obese. “What’s important,” says Acree, “is that you taste something differently than I do. It’s like you’re living in a pink world, and I’m living in a blue world, and we’re talking about the color of the ocean. We’ll never agree.”
But these distinctions are only the beginning. Recent studies suggest that cultures have genetic makeups as well. “When they started decoding the genome,” explains Salemme, “they began to look for differences in the sequences between different populations.” Researchers have now identified about a dozen haplotypes, or collections of persistent mutations within a particular population. Take lactose intolerance: A large percentage of people of African and Asian descent can’t produce the enzyme lactase, which breaks down sugars in milk. Lactose intolerance, however, is relatively uncommon in people of European descent, which may reflect the fact that there’s been a tradition of herding and milking in that part of the world for thousands of years. As scientists begin to home in on the biological foundation of different likes and dislikes, an even more tantalizing possibility arises: In the future, each of us will likely be able to identify our genetic predispositions to food. We might even have a food type, just as we have a blood type: I’m broccoli positive, you’re pumpernickel negative. To be sure, this does not necessarily equate to a like or dislike. As Salemme cautions, we can learn to modify our responses. “There are many things you might not like the first time you taste them, such as single-malt Scotch, but you learn to like them. A lot.” The direction, though, is clear: Soon each of us will carry around our own periodic table of what food chemicals we respond to. You’ll no longer be able to ask dinner guests merely if they eat meat; you’ll have to send them a detailed questionnaire.
But as my V8 taste test shows, all this knowledge of our bodies is beginning to affect what we’ll be putting into our bodies. Food companies are scrambling to come up with artificial additives that might improve or block particular flavors. Senomyx, a San Diego–based company, has raised more than $76 million from businesses such as Nestlé, Coca-Cola, and Campbell Soup to study how to enhance the taste of sugar or salt in packaged foods. In effect, products would trick the taste receptors into perceiving ingredients that aren’t there (or that are there in lesser concentrations), thus allowing, for example, manufacturers to slash the amount of salt in a can of chicken-noodle soup. Further benefiting them, the additive would be in such a tiny amount that it could be referenced in the “artificial flavors” category and not be specifically listed on the label.