Do You Like Black Coffee? It's Probably Because Of Your Genes, Study Says

Specifically, researchers found a genetic variant that reflects a faster caffeine metabolism1—and, not-so-coincidentally, these individuals also have a thing for black coffee. 

"Basically, individuals who have genetic factors that contribute to increased caffeine metabolism learn to appreciate the taste because of that higher metabolism and the psychostimulant effects that they present with," lead study author Marilyn Cornelis, Ph.D., associate professor of preventive medicine at Northwestern, tells mbg over the phone. "They learn to equate those psychostimulant effects to that bitter taste." Essentially: If you have an affinity for black coffee, it might not actually be the taste you love but the energy you feel.  

Cornelis and her team found strong patterns with tea and dark chocolate as well, items that also contain caffeine (albeit at much smaller concentrations than coffee). "It just shows that what we're observing with coffee also extends to other caffeine-containing foods and beverages," she says. "These individuals who have genetic factors contributing to increased caffeine metabolism prefer black coffee over sweetened coffee, dark chocolate over milk chocolate, as well as unsweetened tea versus sweetened tea." So, say, if you're partial to raw, organic cocoa blends over a mild milk chocolate square, again your caffeine metabolism might be playing a role. 

A perhaps obvious distinction, but studies have yet to make that call: "Most of the research that we hear in popular media just talks about how coffee has been associated with this outcome, or it's adversely associated with that outcome, but they don't mention how the coffee is prepared—and that makes a difference," Cornelis notes. 

If you've got a thing for black coffee, dark chocolate, or unsweetened tea, you might have a genetic variant that reflects a faster caffeine metabolism—so it's not exactly the flavor you love but the mental boost you feel. Something to sip on while you mull over the coffee shop menu.