Coffee Drinking May be in Your Genes: Six New Genetic Variants Discovered

Do you like coffee? Then it may be due to your genes. Scientists have found six new genetic variants associated with habitual coffee drinking. The new findings could explain why some people crave coffee in the morning, while others are less prone to seeking out the brew.

"Coffee and caffeine have been linked to beneficial and adverse health effects," said Marilyn Cornelis, one of the researchers, in a news release. "Our findings may allow us to identify subgroups of people most likely to benefit from increasing or decreasing coffee consumption for optimal health."

A given amount of coffee or caffeine has different effects on different people, and genetics have long been suspected of underpinning these differences. However, pinpointing the specific genetic variants has been challenging.

That's why scientists conducted a genome-wide meta-analysis of more than 120,000 regular coffee drinkers of European and African American ancestry. The researchers eventually identified two variants that mapped to genes involved in caffeine metabolism, POR and ABCG2. Two variants were identified near genes BDNF and SLC6A4 that potentially influence the rewarding effects of caffeine. Two others, near GCKR and MLXIPL, had not been previously linked to the metabolism or neurological effects of coffee.

The new findings suggest that people naturally modulate their coffee intake in order to experience the optimal effects created by caffeine. In addition, the strongest genetic factors linked to increased coffee intake likely work by directly increasing caffeine metabolism.

"The new candidate genes are not the ones we have focused on in the past, so this is an important step forward in coffee research," said Cornelis. "Like previous genetic analyses of smoking and alcohol consumption, this research serves as an example of how genetics can influence some types of habitual behavior."

The findings are published in the journal Molecular Psychiatry.