Why do some people love wine while others are indifferent? Accounting for taste has always been a quixotic undertaking, but new research has uncovered important implications for health. Now that the human genome has been sequenced, numerous genes coding for taste receptors have been identified, along with a growing understanding of the role that they play in healthy drinking and longevity. Within these 25+ taste receptor genes there are variations called polymorphisms, resulting in an enormous range of taste perception responses. These polymorphisms of taste receptors account not only for food (and wine) preferences but play a surprisingly broad role in health, with associations between variants in taste receptor genes and Body Mass Index (BMI), cancer, alcohol consumption, and smoking. They are expressed in a number of organs throughout the gastrointestinal system and are involved in regulation of food absorption and metabolism. Variants in some taste receptors modulate homeostasis of blood sugar and insulin, and a specific variant called TAS2R16 is strongly related with longevity, possibly for that reason.
But we get ahead of ourselves. I had long assumed that most people who don’t “get” fine wine had just never had good wine, and then the concept of “supertasters” came to light. These are people who have a specific genetic variant that makes them highly averse to certain bitter tastes; most of us are sort of in the middle, but for every supertaster there is also a non-taster out there. What is now known is that this is an oversimplification; genetic polymorphisms cover a range of flavor experiences including sensitivities for wine tannins and polyphenols. Depending on the genetic hand you were dealt, you may be programmed to perceive an acclaimed wine as bitter and/or sour, or to detect and delight in its every glorious subtlety. Several TAS genes have been identified (TAS2R4, TAS2R5, TAS2R39 and TAS2R7) which code for receptors that are specifically activated by polyphenol compounds present in red wine. There is even evidence that professional wine critics have a specific set of genetic variants imparting them with enhanced sensory capabilities (called an “active gene-environment correlation.”)
So the question is whether there is a common set of taste receptor genes that encodes for an optimal mix of proclivity to moderation in consumption of alcohol, preference for red wine, healthy dietary habits, and the metabolic machinery associated with health and longevity. Given what we now know about the influence of taste receptor polymorphisms on behavior and physiology, it seems to make sense. Genome testing companies already offer an analysis of individual taste receptor variants, so it should be theoretically possible to determine the ideal combination, if there were an acceptable way to cross-reference the data. Even if we could though, it is estimated that overall only around 25% of human longevity relates to genetic factors, and habits of drinking are not strictly pre-programmed. There is evidence that cultural norms have a significant impact on drinking and diet, so taste receptor profiles impart predisposition more than predetermination. Most of us are capable of learning good habits and enjoying decent, if not extravagant wines.