Coffee consumption slows kidney function decline

Coffee drinking may put brakes on kidney function decline over time as compared with nonconsumption, with coffee intake conferring a protective effect on the risk of chronic kidney disease in a dose-dependent fashion, especially among individuals with diabetes, as shown in a study.

For the study, researchers looked at 78,346 Dutch who were free of CKD in the population-based Lifelines Cohort Study. All participants completed food frequency questionnaires at baseline to evaluate coffee consumption, which was categorized as follows: 0 cup, >0-2 cups, >2-4 cups, >4-6 cups, or >6 cups per day.

The study endpoints included annual estimated glomerular filtration rate (eGFR) change and a composite kidney outcome (defined as eGFR <60 mL/min per 1.73 m² or >20 percent eGFR decline). Multivariable linear and logistic regression analyses were used to estimate the associations of coffee consumption (categories and cups/day) with kidney outcomes.

The majority of the participants drank coffee daily (90 percent), with 36 percent consuming >2-4 cups/day. Over a mean of 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 less annual eGFR decline, with β-values ranging from 0.15 (95 percent confidence interval [CI], 0.07–0.22) for >0-2 cups/day to 0.29 (95 percent CI, 0.20–0.38) for >6 cups/day (p<0.001 for trend).

Furthermore, consumption of one more cup of coffee per day reduced the risk of composite kidney outcome by 3 percent (odds ratio, 0.97, 95 percent CI, 0.96–0.99). This inverse association was more pronounced in the subgroup of participants with diabetes.