- Two 2013 reviews considered the effects of coffee on various aspects of health, concluding that coffee consumption is associated with reduced mortality risk4,5.
- Additionally, two 2014 papers suggested that there was no association between coffee intake and an increase in all-cause mortality6,7. One concluded that an inverse association was observed that was similar in men and women, but varied by location with a stronger association observed in Europe and Japan when compared to the USA7.
- Two studies considered associations at specific intakes of coffee. A large prospective study of 90,317 US adults concluded that coffee drinkers had lower risk ratios for overall mortality, and the risk was reduced with increasing cups of coffee, up to 4-5 cups a day. Similar findings were observed for both decaffeinated and caffeinated coffee8. A further review suggested that the largest risk reduction for various health outcomes was observed at 3-4 cups of coffee per day9.
- A 2016 review of over 95,000 individuals suggested that, observationally, coffee intake is associated with a U-shaped lower risk of cardiovascular disease and all-causemortality10.
- Data from a 2017 study of over 500,000 participants found a significant association between a higher coffee consumption (calculated as more than 3 cups per day with 1 cup equal to 237ml) and a lower risk of all-cause mortality. The strongest associations were observed with digestive disease mortality, mainly due to the lower risk of dying from liver disease in both men and women1.
- A population based cohort study, using data from the National Health and Nutrition Examination Survey (NHANES), concluded that a moderate caffeine intake was associated with a decreased risk of all-cause mortality, regardless of the presence or absence of coffee consumption11.
- Research from the Multiethnic Cohort Study concluded that coffee consumption was associated with lower total mortality after adjustment for smoking and other potential confounders, with similar trends seen for both caffeinated and decaffeinated coffee intake. Significant inverse associations were observed in four ethnic groups: African-Americans, Japanese-Americans, Latinos, and Caucasians, however the association in Native-Hawaiians did not reach statistical significance12.
- A 2018 population study of over 120,000 adults considered the effect of coffee consumption, tea consumption, and the substitution of coffee for tea on mortality risk13. A higher coffee intake was significantly, non-linearly related to lower overall and cause-specific mortality in women. The authors suggested that for men, compared to exclusive coffee drinkers, those drinking 30-50% tea showed the lowest mortality risk, and any tea drinking resulted in a greater reduced risk than coffee drinking exclusively. For women, those who drank coffee exclusively, or up to 40% tea had the lowest mortality, but those drinking higher percentages of tea were at increased mortality risk compared to exclusive coffee drinkers13.
