Epidemiological studies have long hinted at the possibility that what we eat greatly influence our state of health, in particular, our relative risk of developing cancer. In recent years there has been an exponential increase in the number of studies investigating how individual components of the diet interact at the molecular level to determine the fate of a cell. It is now apparent that many such molecules can preferentially inhibit the growth of tumor cells, by inducing cell cycle arrest or apoptosis. Besides, the number of signaling pathways and molecular targets involved is continually expanding. Consequently, the picture is becoming ever more complicated, not least because results often appear to be cell type-specific, dose-response relationships are critical, and any one agent appears to have multiple mechanisms of action. In addition most studies have been conducted in cell culture, often with physiologically unachievable concentrations of single agents, making extrapolation to the clinical situation difficult. In this review the mechanisms of action of the popular drink black tea and its polyphenols, theaflavins, are considered in the light of these issues. In fact, black tea and theaflavins activate an array of apoptogenic signaling events thereby ensuing reduced tumor growth. This beverage not only regresses tumor but also protects intrinsic defense machineries of the host from cancer insult. The intrinsic defense systems, e.g., immune and detoxification systems, jeopardized during cancer, are also rejuvenated by black tea. Black tea even reduces tumor-induced hepatotoxicity and protects against oxidative damage generated by the developing tumor. Therefore, acting in a multi-faceted manner, black tea and theaflavins can successfully bring about regression of the tumor and ensure survival of the host. Moreover, being a commonly consumed drink, black tea is considered safe and non-toxic and has potential as a ‘natural’ chemotherapeutic product to be used as an adjunct to the existing clinical procedures, making it a broad-acting and readily distributed cost-effective agent to promote public health. Thus, modern medical research seems to confirm the ancient wisdom that therapy of many diseases may reside in an inexpensive beverage in a "teapot."
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