Korean twin study finds environment outweighs genetics in coffee habits

A joint research team from Seoul National University and Chung-Ang University has found that environmental factors play a larger role than genetics in determining coffee consumption habits among Koreans.

Analyzing 1,106 twins (553 pairs) aged 30 and older, the study published in the journal ‘Behavior Genetics’ determined that genetic factors account for 29% of the individual differences in coffee consumption. The remaining 71% is attributed to unique environmental factors and measurement errors.

The study also examined tea and caffeine intake. The genetic contribution to tea consumption was lower, at 11%, with environmental factors accounting for 89%. For caffeine intake, when categorized into high and low consumption groups, the heritability was estimated at 27%, while continuous variable analysis of caffeine intake showed a genetic influence of 17%.

Researchers noted that while genetic backgrounds contribute to how individuals consume coffee and caffeine—potentially affecting physiological responses and metabolic rates—genetics alone cannot explain these behaviors. This study is particularly significant as previous twin studies on caffeine consumption have primarily focused on Western populations.