Coffee consumption has been associated with a reduced risk of some cancers, but the evidence for renal cell carcinoma (RCC) is inconclusive. We investigated the relationship between coffee and RCC within a large cohort.
Coffee intake was assessed at baseline in the National Institutes of Health-American Association of Retired Persons Diet and Health Study. Among 420 118 participants eligible for analysis, 2674 incident cases were identified. We fitted Cox-regression models to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) for coffee consumption vs non-drinkers.
We observed HRs of 0.94 (95% CI 0.81, 1.09), 0.94 (0.81, 1.09), 0.80 (0.70, 0.92) and 0.77 (0.66, 0.90) for usual coffee intake of <1, 1, 2-3 and ≥4 cups/day, respectively (Ptrend = 0.00003). This relationship was observed among never-smokers (≥4 cups/day: HR 0.62, 95% CI 0.46, 0.83; Ptrend = 0.000003) but not ever-smokers (HR 0.85, 95% CI 0.70, 1.05; Ptrend = 0.35; Pinteraction = 0.0009) and remained in analyses restricted to cases diagnosed >10 years after baseline (HR 0.65, 95% CI 0.51, 0.82; Ptrend = 0.0005). Associations were similar between subgroups who drank predominately caffeinated or decaffeinated coffee (Pinteraction = 0.74).
In this investigation of coffee and RCC, to our knowledge the largest to date, we observed a 20% reduced risk for intake of ≥2 cups/day vs not drinking. Our findings add RCC to the growing list of cancers for which coffee consumption may be protective.
International journal of epidemiology. 2021 Feb 24 [Epub ahead of print]
Jongeun Rhee, Erikka Loftfield, Neal D Freedman, Linda M Liao, Rashmi Sinha, Mark P Purdue
Division of Cancer Epidemiology and Genetics, Occupational and Environmental Epidemiology Branch, National Cancer Institute, Rockville, MD, USA., Division of Cancer Epidemiology and Genetics, Metabolic Epidemiology Branch, National Cancer Institute, Rockville, MD, USA.