W.W. Norton & Company, April 2017 As soon as I decided to write a book on the science of flavor, I knew I wanted to have myself genotyped. Every one of us, I learned through my preliminary research for Flavor: The Science of Our Most Neglected Sense, probably has a unique set of genes for taste and odor receptors. So each person lives in their own flavor world. I wanted to know what my genes said about my own world. Sure enough, there was a lesson there—but not the one I expected.
Our senses of smell and taste detect chemicals in the environment as they bind to receptors on the olfactory epithelium in the nose or on taste buds studding the mouth. From these two inputs, plus a few others, the brain assembles the compound perception we call flavor. Taste is pretty simple: basically, one receptor type each for sweet, sour, salty, and the savory taste called umami, and a family of maybe 20 or more bitter receptors, each of which is sensitive to different chemicals. Smell, on the other hand, relies on more than 400 different odor receptor types, the largest gene family in the human genome. Variation in any of these genes—and, probably, many other genes that affect the pathways involved in taste or smell—should ...