Tea consumption and basal cell and squamous cell skin cancer: results of a case-control study.

BACKGROUND Tea constituents, including polyphenols, are hypothesized to have chemopreventive properties, and inhibit the induction of skin cancers in animal models. OBJECTIVE To explore the association between regular tea consumption (>or=1 cup/d for >or=1 month) and the incidence of squamous cell (SCC) and basal cell (BCC) carcinomas. METHODS A population-based case-control study of 770 individuals with BCC, 696 with SCC, and 715 age- and sex-matched control subjects. RESULTS After adjustment for age, sex, and lifetime history of painful sunburns, ever having consumed tea regularly was associated with a significantly lower risk of SCC (odds ratio [OR] = 0.70; 95% confidence interval [CI] 0.53-0.92), especially among long-term drinkers (>or=47 years consumption: SCC, OR = 0.49; 95% CI 0.29-0.83; P for trend = .008) and among those consuming >or=2 cups/d (OR = 0.65; 95% CI 0.44-0.96; P for trend = 0.013). After adjustment for age and sex, ever having consumed tea regularly was weakly associated with BCC risk (OR = 0.79; 95% CI 0.63-0.98). LIMITATIONS Our case-control study was susceptible to recall bias and to confounding by unknown cancer risk factors associated with tea consumption. CONCLUSIONS Our findings support the existence of an inverse association between tea consumption and skin carcinogenesis.