Coffee, tea, caffeine, and risk of nonmelanoma skin cancer in a Chinese population: The Singapore Chinese Health Study

Abstract

Although epidemiologic studies in populations of European descent suggest a possible chemoprotective effect of caffeine against nonmelanoma skin cancer (NMSC), data in Asian populations are lacking. We examined the relationship of coffee, tea, and caffeine consumption with NMSC risk among Chinese in Singapore. We used data from the Singapore Chinese Health Study, a prospective cohort of 63,257 men and women who were 45 to 74years old at recruitment from 1993 to 1998. Hazard ratios (HRs) and 95% confidence intervals (CIs) were estimated by using multivariable Cox proportional hazard models. Coffee drinking was associated with reduced NMSC risk in a dose-dependent manner (P trend<.0001). Compared with those who drank coffee less than weekly,those who drank 3 or more cups per day had a lower risk of basal cell carcinoma (HR, 0.54; 95% CI, 0.31-0.93) and a lower risk of squamous cell carcinoma (HR, 0.33; 95% CI, 0.13-0.84). Compared with nondrinkers of black tea, daily drinkers of black tea also had a reduced risk of NMSC (HR, 0.70; 95% CI, 0.52-0.94). Caffeine intake reduced NMSC risk in a stepwise manner (P trend=.0025); subjects with a caffeine intake of 400mg/d or more had the lowest risk (HR, 0.59; 95% CI, 0.34-1.04). Consumption of caffeinated drinks such as coffee and black tea may reduce the risk of NMSC among Chinese.