Addicted to coffee? Now you can blame your genes

Scientists have uncovered six genetic variants that determine how much satisfaction you get from caffeine.

"Addicted to coffee? Now you can blame your genes"

The discovery, involving an international team of scientists, could help explain why individuals react differently to caffeine, why some people becomed addicted while others don't, and why coffee is linked to such a broad range of good and bad health effects.

After studying the genomes of more than 120,000 regular coffee drinkers, the scientists identified six new genetic variants that determined how much coffee someone would consume.

"Some of the gene regions determine the amount of coffee that makes individuals feel they are satisfied psychologically and others physiologically,” said Jennie Hui, a health scientist from the University of Western Australia who was involved in the study, in a press release. “What this tells us is that there may be molecular mechanism at work behind the different health and pharmacological effects of coffee and its constituents.”

The results, which are published in the journal Molecular Psychiatry, also suggest that people will naturally moderate their coffee intake dependent on their genes to experience the best effects of caffeine. They found that people who had genes that allowed them to metabolise, or break down, caffeine faster were the ones who drank the most coffee.

This means your genes may determine whether you become “hooked” to coffee or not, and they might also indicate whether coffee will have health benefits for you.

"Coffee and caffeine have been linked to beneficial and adverse health effects. Our findings may allow us to identify subgroups of people most likely to benefit from increasing or decreasing coffee consumption for optimal health," said Marilyn Cornelis from the Harvard School of Public Health, who led the study, in a press release.

Scientists have long suspected that genetic factors are the reason people handle coffee differently, but in the past they'd struggled to narrow down which ones are involved. This international collaboration succeeded due to its sheer size - by scanning the entire genomes of 120,000 coffee drinkers, the researchers were able to spot complex genetic patterns and links.

Out of the six new genetic variants discovered, two were found that are involved in caffeine metabolism, and two that potentially influence the rewarding effects of caffeine. The two other genes were discovered near genes that are involved in glucose and lipid metabolism, and the scientists are currently studying their link to caffeine further.

"Like previous genetic analyses of smoking and alcohol consumption, this research serves as an example of how genetics can influence some types of habitual behaviour," said Daniel Chasman from Brigham and Women's Hospital and the study's senior author.