The scientific evidence, which I have reviewed thoroughly, is quite clear and entirely convincing all on its own: Taste buds are adaptable little fellas. When they can't be with foods they love, they learn to love the foods they're with.
Even in the absence of scientific studies showing how readily taste preferences can change, it simply stands to reason that they would. The job of taste buds is not to make us happy or unhappy, although they can do both. The job of taste buds is all about survival; they are sentinels at the main gate to our inner world. Their job is to distinguish friend from foe.
The trouble, though, is that we have to be able to make new friends. In native context, this is referred to as the omnivore's paradox. Any time our Stone Age ancestors tried a new food, there was a chance it might kill them - so they tended to be quite reticent about doing so (i.e., neophobia = fear of the new). On the other hand, as they wandered, if they didn't try new foods, they were destined to starve - so they were prone to give it a shot (i.e., neophilia = love of the new).
The adaptive response to this is taste buds with intrinsic preferences for the tastes that are most reliably safe, sweet in particular, and the equally strong tendency to favor the familiar. The food we know and have eaten before is unlikely to kill us this time, because it didn't kill us last time.
Closely linked to the power of the familiar is the capacity to habituate to new foods. We have a certain reticence to foreign foods at first, simply because they are foreign. But if we stick with a food for a while, we tend to like it more and more as it takes on all the reassuring comforts of home. A food about which we were quite ambivalent at first can well turn out to be one of our favorites over time. Beer and wine may be good examples. These are certainly acquired tastes, but after that period of acquisition, any oenophile such as yours truly will count a great wine among the greatest of all culinary achievements. So there you go.
That habitation to wine is not unique - it happens to many different foods, all the time. Children tend not to like the slight bitterness of many vegetables, but acclimate over time. Anyone who has ever switched from whole milk to skim knows how unsatisfying skim was at first, and how unpalatable whole turned out to be after the switch was a done deal.
So, we have modern science, our Stone Age experience, common sense and innumerable personal anecdotes to make the case that taste buds are adaptable. We also have culture. Mexican, Japanese and Inuit babies are all but indistinguishable genetically - all of humanity is. Certainly, our taste buds are all close variations on a very common theme. And yet, Mexican babies learn to love hot chilis, Japanese babies learn to love equally hot wasabi and Inuit babies learn to love (presumably) seal. We learn to love the foods we're with.
But then again, since we are all biologically the same, we have a strong and innate predisposition to love foods rich in sugar, other sweeteners, salt, starch and fat. These taste preferences seem to transcend all cultures. Just look at the geographic footprint of those golden arches. Whatever you grew up eating, you can learn to love French fries pretty quickly.
Why? Back to that issue of taste buds as sentinels at the gate, they lower their guard and bid a hearty welcome to the flavors most associated with survival in a natural world. In our native nutritional habitat, sweet was a relatively rare and, as noted, reassuringly safe encounter. Our taste buds welcome it. Few foods in nature are naturally salty, and we need salt to survive - so our taste buds welcome it. Fat is the most concentrated source of calories, and in our native habitat, fat was relatively scarce, so - you guessed it - our taste buds welcome it.
Now, since I know all about this from the scientific and anthropology literature, how likely do you think it is that the PhDs in nutritional biochemistry and food science hired by the big food companies don't know about it? If you guessed "zero probability," you win the door prize.
[Read: The Obesity Paradox.]
We have heard for years about willful manipulations of food formulations to exploit our native preferences and innate vulnerabilities, most recently from Michael Moss. And this leads to a toxic impasse and something of a dysfunctional collusion.
The impasse is that we have been getting so much highly adulterated junk food with copious and unnecessary additions of sugar, salt and fat that it has become the prevailing familiar. And, as you will recall, we like the familiar.
And that's where the collusion starts. We can rant about food industry transgressions all we want; we reward them for the same mischief at countless cash registers every day. They make ever-junkier food, which in turn gets us used to ever-junkier food, which in turn makes us prefer ever-junkier food. But we bought it, and habituated to it, in the first place. So we encouraged them; they encouraged us; and we have met the enemy, and it really is both of us. This collusion, and the resulting impasse, accounts for a lot of preventable obesity and chronic disease.
But it's entirely fixable, and you don't need any help from Congress. Just as eating ever-junkier food can make you come to prefer it, so can eating ever more nutritious food. By learning how to trade up choices in every food category, you derive an immediate benefit by cutting out gram after gram of sugar, milligram after milligram of sodium, and adding fiber, antioxidants and other valuable nutrients. You are likely to cut calories and lose weight, too, because one of the many virtues of more nutritious foods is that they fill us up on fewer calories. If you just traded up most of your choices and called it a day, you would be much better off.
But there's no reason to stop there. As you trade up your choices and cut out superfluous sugar, salt, trans fat and food chemicals, you also put your taste buds through rehab. They become more sensitive to sugar and salt. They may come to recoil at the approach of unhealthy oils and unnatural chemicals. And then, you are standing on the threshold to the promised land of dietary health.
Food is a source of great pleasure, and should be exactly that. But vitality is at least as great a source of pleasure, and should be exactly that. We should not need to mortgage either to pay for the other. By making ever better foods in every possible category the familiar choices, you come to prefer them in relatively short order. Your taste buds then encourage you to make further improvements, because that's what rehabilitating them does. And when enough of us have made this transition, our collective actions at those countless cash registers will change, and so will the food supply. Big Food isn't preferentially interested in selling us junk; they are interested in selling us what we buy. When we don't buy junk, it will go away - and along with our prevailing taste preferences, we will have changed the food supply.
Such is the promise of taste bud rehab: loving food that loves us back, in a context that makes the healthful choice the universally accessible norm. All that stands in the way is our taste for the status quo. We can start to change it any time we like.
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David L. Katz, MD, MPH, FACPM, FACP, is a specialist in internal medicine and preventive medicine, with particular expertise in nutrition, weight management, and chronic-disease prevention. He is the founding director of Yale University's Prevention Research Center, and principal inventor of the NuVal nutrition guidance system. Katz was named editor-in-chief of Childhood Obesity in 2011, and is president-elect of the American College of Lifestyle Medicine.