Protection by tea against UV-A + B-induced skin cancers in hairless mice

Consumption of tea, especially green tea, has been shown to reduce the incidence of ultraviolet (UV)-related skin tumors in hairless mice. Because milk is added to much of the tea consumed in Western cultures, we have studied the effects of including milk in the tea consumed by hairless mice receiving simulated solar radiation. Under these conditions, mice consuming tea with 10% whole milk had 30% fewer papillomas, 50% fewer tumors, and 55% smaller lesions than mice consuming water. Mice consuming tea alone had fewer papillomas and tumors than mice consuming tea with milk; however, the difference in area affected was not statistically significant. In separate experiments, there was a significant dose response to black tea as a preventive against UV-related skin lesions, and also consumption of black tea was associated with a small but significant reduction in the incidence of papillomas in mice previously exposed to UV radiation. The results of these studies demonstrate that, in hairless mice, black tea can inhibit the formation of UV-induced skin tumors in a dose-dependent manner and, even with the addition of milk, can still inhibit the growth of UV-related skin tumors.