"Association of Coffee Drinking with Total and Cause-Specific Mortality"
publikovane v New England Journal of Medicine (doveryhodny zdroj :)
13 rokov, 400.000 (!) ludi, sledovana a porovnana mortalita medzi tymi co piju <1, 1, 2-3, 4-5 a 6+ cups daily
Zaver: "coffee consumption was inversely associated with total and cause-specific mortality"

(najlepsie dopadlo 4-5 cups :)
http://www.nejm.org/doi/full/10.1056/NEJMoa1112010