Why do you swig bitter, dark roast coffee or hoppy beer while your coworker guzzles sweet cola? Scientist Marilyn Cornelis searched for variations in our taste genes that could explain our beverage preferences, because understanding those preferences could indicate ways to intervene in people’s diets. To Cornelis’ surprise, her new Northwestern Medicine study showed taste preferences for bitter or sweet beverages aren’t based on variations in our taste genes, but rather genes related to the psychoactive properties of these beverages. “The genetics underlying our preferences are related to the psychoactive components of these drinks,” said Cornelis, assistant professor of preventive medicine at Northwestern University Feinberg School of Medicine. “People like the way coffee and alcohol make them feel. That’s why they drink it. It’s not the taste.” Cornelis did find one variant in a gene, called FTO, linked to sugar-sweetened drinks. People who had a variant in the FTO gene — the same variant previously related to lower risk of obesity — surprisingly preferred sugar-sweetened beverages. “It’s counterintuitive,” Cornelis said. “FTO has been something of a mystery gene, and we don’t know exactly how it’s linked to obesity. It likely plays a role in behavior, which would be linked to weight management. “To our knowledge, this is the first genome-wide association study of beverage consumption based on taste perspective,” said Victor Zhong, the study’s first author and postdoctoral fellow in preventive medicine at Northwestern. “It’s also the most comprehensive genome-wide association study of beverage consumption to date.” Alan Kuang is also a Northwestern author on the paper.