Coffee, tea, and melanoma risk among postmenopausal women.

Laboratory research suggests that components in coffee and tea may have anticarcinogenic effects. Some epidemiologic studies have reported that women who consume coffee and tea have a lower risk for melanoma. We assessed coffee, tea, and melanoma risk prospectively in the Women's Health Initiative - Observational Study cohort of 66,484 postmenopausal women, followed for an average of 7.7 years. Coffee and tea intakes were measured through self-administered questionnaires at baseline and at year 3 of follow-up. Self-reported incident melanomas were adjudicated using medical records. Cox proportional hazard models were used to estimate risk, adjusting for covariates, with person-time accumulation until melanoma diagnosis (n=398), death, loss to follow-up, or through 2005. Daily coffee [hazard ratio (HR)=0.87, 95% confidence interval (CI) 0.68-1.12] and tea (HR=1.03, 95% CI 0.81-1.31) intakes were not significantly associated with melanoma risk compared with nondaily intake of each beverage. No significant trends were observed between melanoma risk and increasing intakes of coffee (P for trend=0.38) or tea (P for trend=0.22). Women who reported daily coffee intake at both baseline and year 3 had a significantly decreased risk compared with women who reported nondaily intake at both time points (HR=0.68, 95% CI 0.48-0.97). Consistent daily tea intake was not associated with decreased melanoma risk. Overall, there is no strong evidence that increasing coffee or tea consumption can lead to a lower melanoma risk. We observed a decrease in melanoma risk among long-term coffee drinkers, but the lack of consistency in the results by dose and type cautioned against overinterpretation of the results.