'Coffee and caffeine have been linked to beneficial and adverse health effects,' researchers.
People's coffee-drinking habits are linked to their genes, scientists say.
A large-scale study, which analysed 20,000 regular coffee drinkers of European and African American ancestry, identified six new genetic variants associated with habitual coffee drinking.
The genome-wide meta-analysis, led by Harvard School of Public Health and Brigham and Women's Hospital
researchers, helps to 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.
The researchers, who are part of the Coffee and Caffeine Genetics Consortium, identified two variants that mapped two genes involved in caffeine metabolism, POR and ABCG2.
Two variants were also identified near genes BDNF and SLC6A4 that potentially influence the rewarding effects of caffeine.
