My friend Dawn hates the taste of eggs. As a little kid, she ate eggs that had been cooked in burnt butter. Her brain linked the revolting acrid taste of the burnt butter with the taste of eggs, and to this day that link is stuck in the basal parts of her brain to the point that she can’t eat eggs. A taste aversion —a strong dislike for a food, but not one based on an innate biological preference—typically stems from prior bad experiences with food, often occurring in childhood like Dawn’s burnt-butter eggs experience. A foodborne illness is a common cause.
Taste aversions are fascinating because they’re entirely learned associations. The food that triggers the illness is correctly identified only part of the time. Typically, the blame is pinned on the most unfamiliar thing in a meal, known as sauce Béarnaise syndrome. Sometimes the illness isn’t even food-related, but a negative association is still learned and becomes tied to the suspected culprit. This type of conditioned taste aversion is known as the Garcia effect, named for psychologist John Garcia, who determined that he could create taste aversions in rats by invoking nausea when they were exposed to sweetened water. As further proof that we’re at the mercy of our subconscious, consider this: even when we know we’ve misidentified the cause of an illness (“It couldn’t be Joanna’s mayonnaise salad—everyone else had it and they’re fine!”), an incorrectly associated food aversion will still stick.
Sometimes only a single exposure that results in foodborne illness is all it takes for your brain to create the negative association. One of the cleverest examinations of taste aversion was done by Carl Gustavson as a grad student stuck at the ABD (all but dissertation) point of his PhD. Reasoning that taste aversion could be artificially induced, he trained free-ranging coyotes to avoid sheep by leaving (nonlethally) poisoned chunks of lamb around for the coyotes to eat. They quickly learned that the meat made them ill, and thus “learned” to avoid the sheep. As tempting as it may be, I don’t recommend this method for kicking a junk food habit, but it does hold an odd appeal.
What can you do to overcome a taste aversion? To start with, you have to be willing and open. You may feel that eggs are disgusting, and if you’re unwilling to unwire that association, your chances of eating an omelet are rather low. Repeated exposures to small quantities of the offending item, in situations where you feel comfortable, will eventually remove the association between the food item and negative memory (called extinction). Remember, start with small quantities and use consistent repeated exposures in a supported environment. If it’s too much at first, try changing some aspects of the food, such as its texture or the cooking technique, so that the flavor association isn’t as strong.
*See Also: What is Flavor: A Lesson in Orthonasal Olfaction