Posted on July 02, 2018
Researchers at the National Cancer Institute evaluated the coffee-drinking habits of nearly half a million people, using demographic, lifestyle, and genetic data from the UK Biobank, to determine whether genetic variation in caffeine metabolism affects associations between coffee drinking and mortality risk. The investigators confirmed previous studies showing an inverse association between coffee drinking and mortality during the study period and found similar associations in participants with genetic variants conveying both faster and slower caffeine metabolism. The findings were published on July 2, 2018, in JAMA Internal Medicine.
The rapidity of caffeine metabolism varies substantially between people. Prior data from case-control studies had suggested that coffee drinking may increase the risk of hypertension and myocardial infarction among individuals with genetic variants indicating slower caffeine metabolism. However, these prior studies assessed coffee drinking after disease occurrence and did not examine overall or cardiovascular disease mortality. In the current study, coffee drinkers were less likely to die of cardiovascular disease and cancer than non-drinkers. Similar findings were observed for participants drinking ground, instant, and decaffeinated coffee.
All together, these findings suggest that inverse associations between coffee and mortality may be attributable to non-caffeine constituents and may provide reassurance to coffee drinkers. Further research is needed to understand the mechanisms underlying the observed associations.
Reference: Loftfield E, et al. Association of Coffee Drinking With Mortality by Genetic Variation in Caffeine Metabolism. JAMA 2018 July 2. DOI:10.1001/jamainternmed.2018.2425 [Epub ahead of print]