Preventing Prostate Cancer with Green Tea

“Prostate cancer is a leading cause of illness and death among men in the United States and Western Europe,” but rates in Asia can be as much as ten times lower. Perhaps Asians are genetically less likely to get prostate cancer? No. Japanese Americans and Chinese Americans have high prostate cancer rates as well.

In the United States, up to nearly one in three men in their 30s already has small prostate cancers brewing and that grows to nearly two thirds of American men by their 60s. On autopsy, most older men were found to have unknown cancerous tumors in their prostates. What’s remarkable is that Asian men seem to have the same prevalence of these hidden, latent prostate cancers on autopsy, but they don’t tend to grow enough to cause problems. In Japan, men tend to die with their tumors rather than from their tumors. Of course, that’s changing as Asian populations continue to Westernize their diets. 

What is it about Western diets that fuels cancer growth? It could be carcinogens in the diet accelerating the growth of cancer. Indeed, the typical American diet is rich in animal fats and meats, but it could also be something protective in Asian diets that is slowing the cancer growth, such as fruits, vegetables, soy foods, or green tea.

How might we determine if there is a link between tea consumption and the risk and progression of prostate cancer? Dozens of studies have examined whether tea drinkers tend to get less cancer in the future and if cancer victims tend to have drank less tea in the past. Although the results have been mixed, overall, tea consumption was associated with a lower risk of prostate cancer. So, tea consumption might indeed play a protective role. However, just because tea drinkers get less cancer doesn’t mean it’s necessarily because of the tea. Perhaps drinking tea is just a sign of a more traditional lifestyle and maybe tea drinkers are less likely to be patrons of the thousand KFC fast-food restaurants now in Japan.

In vitro studies performed in a lab allow for as many factors to be controlled as possible. When everything is removed from the equation except for green tea and prostate cancer, dripping green tea compounds directly on prostate cancer cells in a petri dish can cause them to self-destruct. But we do not appear to absorb enough green tea compounds into our bloodstream to reach those kinds of levels.

This may explain why some studies failed to find an association between tea drinking and cancer. Maybe we’re not drinking enough? In the United States, for example, the “high” tea-drinking group may be defined as more than five cups of tea a week. In Japan, however, the “high” tea-drinking group can consume five or more cups a day, which was associated with about halving the risk of aggressive prostate cancer. How? Apparently, it was not by preventing the formation of the cancer in the first place, but perhaps by slowing or stopping the cancer’s growth. If green tea can stop the growth of prostate cancer, why not try giving green tea to prostate cancer patients to see if it will help?