Does the mere mention of a certain food make you sick to your stomach? Say “liver” or “Brussels spouts?” Well, the feeling may be all in your head. In fact, experts say that even though you may think you hate a certain food, you may actually love it, but you don’t realize it because your brain is tricking you.

It’s a psychological condition called “food aversion” that dates back to caveman days. Experts say that when our ancestors ate a food that made them sick, if they survived the experience, their brain would condition them to feel sick anytime they saw, smelled, or even thought about it. That way, they’d never eat it again. Which was a lifesaving move in the days before modern medicine.

Well today, our brains are wired the exact same way. Which means one negative experience with food can turn you off for life. In fact, the effect is so strong that patients undergoing chemotherapy are cautioned to avoid their favorite foods. Because it’ll teach their brain to equate their favorite foods with feeling horribly nauseous. And experts say that a lot of people develop aversions for the wrong food.

For example, say you try Indian food for the first time……Only to get sick hours later. Your brain’s caveman mentality will kick in, telling you that the Indian food was the culprit. Because it was the last thing you ate. But experts say that it could have been anything you ate that day, from sour milk in your morning coffee, to an undercooked hamburger at lunch.

The good news is that experts say food aversion is often reversible and that you can trick your brain into liking a food. How? Before you eat a food from your “sick list,” tell yourself that it’s perfectly fine and won’t make your stomach upset.

Bottom line: It’s mind over matter.