A new, large-scale study has identified six new
genetic1 variants2 associated with
habitual3 coffee drinking. The genome-wide meta-analysis, led by Harvard School of Public Health and Brigham and Women's Hospital researchers, helps explain why a given amount of coffee or caffeine has different effects on different people and provides a genetic basis for future research exploring the links between coffee and health. "Coffee and caffeine have been linked to beneficial and
adverse4 health effects. Our findings may allow us to identify subgroups of people most likely to benefit from increasing or decreasing coffee consumption for
optimal5 health," said Marilyn Cornelis, research associate in the Department of Nutrition at Harvard School of Public Health and lead author of the study.
Genetics have long been suspected of contributing to individual differences in response to coffee and caffeine. However,
pinpointing8 the specific genetic variants has been challenging.
The researchers, part of the Coffee and Caffeine Genetics Consortium, conducted a genome-wide meta-analysis of more than 120,000 regular coffee drinkers of European and African American
ancestry9. They identified two variants that mapped to
genes10 involved in caffeine
metabolism11, POR and ABCG2 (two others, AHR and CYP1A2 had been identified
previously12). Two variants were identified near genes BDNF and SLC6A4 that potentially influence the rewarding effects of caffeine. Two others -- near GCKR and MLXIPL, genes involved in
glucose13 and lipid metabolism -- had not previously been linked to the metabolism or neurological effects of coffee.
The findings suggest that people naturally
modulate14 their coffee
intake15 to experience the optimal effects exerted by caffeine and that 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," said Daniel Chasman, associate professor at Brigham and Women's Hospital and the study's senior author.