Coffee may protect against chronic kidney disease

Coffee consumption appears to slow down kidney function decline and reduce the risk of chronic kidney disease (CKD), according to a large Dutch population-based cohort study.

The study included 78,346 participants without CKD at baseline. All participants completed food frequency questionnaires at baseline to provide information regarding their coffee intake.

Researchers evaluated the annual change in estimated glomerular filtration rate (eGFR) and a composite kidney outcome (defined as eGFR <60 mL/min per 1.73 m² or >20-percent decline in eGFR). Multivariable linear and logistic regression analyses were used to examine the associations between coffee consumption (categories and cups/day) and kidney outcomes.

Of the participants, the vast majority (90 percent) drank coffee daily, with 36 percent consuming between 3 and 4 cups per day. In unadjusted models, the annual eGFR change ranged from −2.86 mL/min per 1.73 m² for abstainers to −2.35 mL/min per 1.73 m² for participants consuming >6 cups/day.

Over 3.6 years follow-up, the composite kidney outcome occurred in 11.1 percent of participants. Multivariable models showed that compared with nonconsumption, higher coffee consumption was associated with significantly less annual eGFR decline (>0–2 cups/day: β, 0.15, 95 percent confidence interval [CI], 0.07–0.22; >6 cups/day: β, 0.29, 95 percent CI, 0.20–0.38; p<0.001 for trend).

Of note, drinking one more cup of coffee per day conferred a 3-percent reduction in the risk of the composite kidney outcome (OR, 0.97, 95 precent CI, 0.96–0.99).

The favourable effect of coffee intake on kidney outcomes was especially pronounced in a subgroup of participants with diabetes.