Black Tea Consumption and Risk of Skin Cancer: An 11-Year Prospective Study.

Tea consumption has been shown to protect against skin carcinogenesis in laboratory-based studies; however, epidemiological evidence is limited and inconsistent. This prospective study examined the association between black tea consumption and the incidence of basal cell carcinoma (BCC) and squamous cell carcinoma (SCC). Usual black tea consumption was estimated from food frequency questionnaires completed in 1992, 1994, and 1996 by 1,325 Australian adults. All histologically confirmed skin cancers diagnosed in participants from 1997 to 2007 were recorded. Relative risks (RRs) and 95% confidence intervals (CIs) were assessed using generalized linear models with Poisson and negative binomial distributions and adjusted for confounding factors including skin phenotype and sun exposure. Compared with never drinking black tea, drinking ≥4 cups/day was not associated with BCC (RR = 1.03, 95% CI: 0.70-1.53; P-trend = 0.74) or SCC (RR = 1.25, 95% CI: 0.71-2.19; P-trend = 0.29) in person-based analyses. Stratification by previous history of skin cancer as well as tumor-based analyses also showed no significant associations between black tea intake and incidence of BCC or SCC tumors. Our results do not support the hypothesis that high black tea consumption reduces risk of skin cancer, including in people with a previous history of skin cancer.