A large new genome-wide meta-analysis has identified six previously unreported genetic variants linked to habitual coffee consumption, offering fresh insight into why people experience different effects from the same amount of coffee or caffeine. Led by researchers from the Harvard T.H. Chan School of Public Health and Brigham and Women’s Hospital, the study provides a genetic foundation for future research into how coffee and caffeine relate to health outcomes.
“Coffee and caffeine have been associated with both beneficial and adverse health effects,” said Marilyn Cornelis, research associate in the Department of Nutrition at Harvard and the study’s lead author. “These genetic findings may help identify groups of people who are more likely to benefit from increasing or decreasing coffee intake for better health.”
The study was published online in October 2014 in the journal Molecular Psychiatry and represents one of the largest investigations to date of genetic influences on regular coffee drinking.
The research team, part of the Coffee and Caffeine Genetics Consortium, performed a genome-wide meta-analysis of more than 120,000 habitual coffee drinkers of European and African American ancestry. The analysis identified six loci associated with habitual coffee intake. Two of these loci—POR and ABCG2—map to genes involved in the metabolism and transport of caffeine, complementing earlier findings that implicated AHR and CYP1A2. Two other loci are located near BDNF and SLC6A4, genes that are plausibly related to neural reward processes and might influence the pleasurable or reinforcing effects of caffeine. The remaining two loci are close to GCKR and MLXIPL, genes with known roles in glucose and lipid metabolism; these had not been previously linked to coffee’s metabolic or neurological effects.
These findings support the idea that individuals tend to self-regulate coffee intake to achieve particular physiological or subjective effects of caffeine. In particular, the strongest genetic contributors to higher coffee consumption appear to act by increasing the rate at which the body metabolizes caffeine, which could lead people to consume more to maintain desired effects.
“Some of the new candidate genes are different from those researchers have focused on previously,” Cornelis noted. “This represents an important advance in understanding the biology underlying coffee consumption.”
Daniel Chasman, associate professor at Brigham and Women’s Hospital and the study’s senior author, added, “This work is consistent with genetic analyses of other habitual behaviors, such as smoking and alcohol use, and illustrates how genetic variation can influence everyday consumption patterns.”
Beyond identifying specific genetic variants, the study’s broader implications include improving our understanding of how caffeine affects health and helping to tailor dietary recommendations. If particular genetic profiles predict stronger or weaker responses to caffeine, clinicians and researchers could eventually use this information to recommend personalized levels of consumption for optimal health effects. The findings also open new research avenues into how metabolism and reward pathways interact to shape habitual behaviors like coffee drinking.
This research received institutional support from USC.
Contact: Todd Datz – Harvard
Source: Harvard press release
Image Source: Public domain image credited to PeterDargatz
Original Research: The peer-reviewed article is titled “Genome-wide meta-analysis identifies six novel loci associated with habitual coffee consumption” by Marilyn C. Cornelis and colleagues, published in Molecular Psychiatry (published online October 3, 2014). DOI: 10.1038/mp.2014.107.