Consuming ground, instant or decaffeinated coffee was inversely associated with all-cause mortality even in individuals who drank 8 or more cups per day and had fast or slow caffeine metabolism, according to findings published in JAMA Internal Medicine.
“Prospective cohorts in North America, Europe and Asia show consistent inverse associations between coffee drinking and mortality, including deaths from cardiovascular disease and some cancers,” Erikka Loftfield, PhD, from NIH, and colleagues wrote. “However, concerns about coffee, particularly among people with common genetic polymorphisms affecting caffeine metabolism and among those drinking more than 5 cups per day, remain.”
Loftfield and colleagues investigated the associations between heavy coffee consumption (6 or more cups per day) and mortality by genetic caffeine metabolism score by analyzing data from 498,134 adults who participated in the UK Biobank study (mean age, 57 years; 54% women; 78% coffee drinkers).
Participants completed a questionnaire on how often they drink coffee and what type of coffee they drink (ground, instant or decaffeinated). The researchers measured caffeine metabolism using a genetic score of previously identified polymorphisms in AHR, CYP1A2, CYP2A6 and POR.
Consuming ground, instant or decaffeinated coffee was inversely associated with all-cause mortality even in individuals who drank 8 or more cups per day and had fast or slow caffeine metabolism.
During the 10-year follow-up, there were 14,225 deaths, which were mainly due to cancer (58%), CVD (20%) and respiratory disease (4%).
As coffee consumption increased, the risk of all-cause mortality decreased (HR for drinking less than 1 cup of coffee per day = 0.94 [95% CI, 0.88-1.01]; HR for drinking 1 cup per day =0.92 [95%CI, 0.87-0.97]; HR for drinking 2 to 3 cups per day = 0.88 [95% CI, 0.84-0.93]; HR for drinking 4 to 5 cups per day = 0.88 [95% CI, 0.83-0.93]; HR for drinking 6 to 7 cups per day = 0.84 [95% CI, 0.77-0.92]; and HR for drinking 8 or more cups per day = 0.86 [95% CI, 0.77-0.95]).
Similar inverse associations were observed for coffee drinking and all-cancer and all-CVD mortality, as well as instant, ground and decaffeinated coffee and mortality. Ground coffee showed stronger associations than instant and decaffeinated coffee.
Genetic caffeine metabolism score did not affect these associations.
“Our results are based on observational data and should be interpreted with caution,” Loftfield and colleagues concluded. “Nevertheless, these results provide further evidence that coffee drinking can be part of a healthy diet and may provide reassurance to those who drink coffee and enjoy it.” – by Alaina Tedesco
The authors report no relevant financial disclosures.