A fan of black coffee, dark chocolate? It’s in your genes

CHICAGO

Prefer your coffee black? Then you probably like dark, bitter chocolate, according to new research identifying a genetic basis for those preferences, CNN has reported.

If that’s you, then congratulations -- you are the lucky genetic winner of a trait that may offer you a boost toward good health, according to caffeine researcher Marilyn Cornelis, an associate professor of preventive medicine at Northwestern University Feinberg School of Medicine.

“I tell people my cup of tea is coffee research,” Cornelis said. “It’s a hot topic.”

Why hot? Because studies find moderate amounts of black coffee -- between three and five cups daily -- has been shown to lower the risk of certain diseases, including Parkinson’s, heart diseases, Type 2 diabetes and several types of cancer.

But those benefits are likely to be more pronounced if the coffee is free of all of the milks, sugars and other fattening flavorings we tend to add. In prior research, Cornelis and her team discovered that a genetic variant may contribute to why some people enjoy numerous cups of coffee a day, while others do not.

“People with the gene metabolize caffeine faster, so the stimulating effects wear off faster, and they need to drink more coffee,” she said. “This could explain why some individuals seem to be fine consuming a lot more coffee relative to someone else who might get jitters or become very anxious,” she added.

In a new study published in Nature Scientific Reports, Cornelis analyzed more precise types of coffee drinkers, separating black coffee lovers from cream and sugar lovers.

“We found coffee drinkers with the genetic variant that reflects a faster metabolism of caffeine prefer bitter, black coffee,” Cornelis said. “We also found the same genetic variant in people who prefer plain tea over sweetened, and bitter, dark chocolate over the more mellow milk chocolate.”