Ever wonder why you love cookies but hate Brussels sprouts? Turns out it’s all in your head, which means it may be possible to actually reprogram your taste preferences.

Scientists have long known that smell influences taste, but they haven’t been sure exactly how. Recently, researchers from Oregon State University (OSU) conducted a series of studies on the role that the human nose and tongue have in recognizing the flavor of foods, and reached two conclusions: 

• Our brains, rather than our mouths, determine our sense of taste
• We’re genetically wired to like sweet and salty-tasting substances and to avoid sour and bitter ones

The latter finding was useful for our ancestors, the researchers said, because it helped them avoid poisonous or spoiled substances and nosh up on foods that provided energy for hunting and simply staying alive. But today, when the only wooly mammoths we see are on TV, our love of sugar and salt is more likely to make us fat and sick rather than fit and healthy. 

The good news is that the OSU researchers believe the brain’s role in flavor perception means that what we think is tasty is largely a learned behavior. That means we should be able to teach our brains to like bitter-tasting vegetables and other nutrient-rich foods just as much as we like pastries and potato chips. 

In studies published in November 2010 and February 2012 in the journal Chemical Senses, the OSU researchers gave adults foods that were sweet, salty, sour and bitter. Based on the subjects’ responses, the researchers found that even though the tongue, which determines the taste of a food, and the nose, which determines its smell, are close together, they don’t interact. Instead, the brain combines these two senses and thus decides how we perceive the flavor of a food.

The researchers found that the orbital frontal cortex right behind our eyes integrates our brain’s taste and smell centers into a single flavor perception, which then gets relayed to the tongue and gives the impression of flavor in the mouth. 

“This is a trick the brain plays on us,” said study lead author Juyun Lim. Take vanilla, for instance. “Vanilla has no taste at all,” she said. “It’s a smell, and the pleasant sensation is coming not from your mouth but from the nose.”

The opposite is true for cruciferous vegetables like cauliflower or Brussels sprouts. Many people don’t like their taste, Lim said, “but what they are mainly reacting to is the smell of these vegetables, which includes a defensive compound that makes even other animals shy away from eating them. Find a way to improve their smell, and you’ll find a way to make people enjoy eating them.”