Is coffee harmful? if looking for longevity, say yes to the coffee, no to the sugar

摘要

Liu et al reported a significant increase in all-cause mortality for men (hazard ratio, 1.56; 95% CI, 1.30-1.87) and women (hazard ratio, 2.13; 95% CI, 1.26-3.59) younger than 55 years who consumed more than 4 cups of coffee per day. The data came from a longitudinal study that measured coffee consumption preceding mortality by as much as 32 years. We can be much more confident of temporality than causality in this study. In fact, there are several reasons to believe that the associations found are not causal. First, all but the associations between the highest levels of coffee drinking and mortality became statistically insignificant in fully adjusted models. Second, the "fully" adjusted models did not include potentially important confounders, only some of which have been discussed in previous critiques.