Scientists say DNA determines coffee consumption

Is Java in the genes? New research from The Coffee and Caffeine Genetics Consortium has brought us closer than ever in the quest to understand why coffee affects people differently.

Findings published today in Molecular Psychiatry confirm the long suspected belief that genetics determine coffee drinking behavior. Scientists have now pinpointed six new gene variations that are more common in those who gulp down the caffeinated beverage frequently.

That’s in addition to two previously identified genetic variants that each code for biological traits. We now have eight loci on record that account for an underlying propensity to drink coffee.

The large-scale study of 120,000 regular consumers provided researchers at the Harvard School of Public Health and Brigham Women’s hospital with ample data. In analyzing the subjects’ genetic makeup via DNA sequencing and comparing it to self-reported coffee drinking figures, the scientists were able to determine why some people need more of the stimulant than others for optimal caffeine effect.

“Like previous genetic analyses of smoking and alcohol consumption, this research serves as an example of how genetics can influence some type of habitual behavior,” said Daniel Chasman, associate professor at Brigham and Women’s Hospital and the study’s senior author.

The most notable loci discoveries were named POR and ABCG2, and act indirectly by altering the metabolism of caffeine. BDNF and SLC6A4, loci perceptive to the rewarding and reinforcing properties of caffeine, were also found to be predictive of coffee drinking. Last identified were GCKR and MLXIPL, two loci previously not linked to behavior, but prevalent in high consumers. That was a surprise to researchers. They are involved in glucose and lipid metabolism.

The findings are relevant to coffee’s widespread popularity and availability, which has spurred continual health concern debates. According to the study, the newest edition of the Diagnostic and Statistical Manual of Mental Disorders lists both caffeine intoxication and withdrawal as disorders.

Marilyn Cornelis, research associate in the Department of Nutrition at Harvard School of Public Health and lead author of the study, believes the data could lead to improvements in healthcare.

“Our findings may allow us to identify subgroups of people most likely to benefit from increasing or decreasing coffee consumption for optimal health.”