Green Tea May Slow Prostate Cancer Progression

According to results of a study published in Cancer Prevention Research, a journal of the American Association for Cancer Research, men with prostate cancer who consumed the active compounds in green tea demonstrated a significant reduction in serum markers predictive of prostate cancer progression.

Green tea is the second most popular drink in the world, and some epidemiological studies have shown health benefits with green tea, including a reduced incidence of prostate cancer; However, some human trials have found contradictory results. The few trials conducted to date have evaluated the clinical efficacy of green tea consumption and few studies have evaluated the change in biomarkers, which might predict disease progression.

Researchers at Feist-Weiller Cancer Center, LSU Health Sciences Center-Shreveport, conducted this clinical trial to determine the effects of short-term supplementation with green tea's active compounds on serum biomarkers in patients with prostate cancer. The biomarkers include hepatocyte growth factor (HGF), vascular endothelial growth factor (VEGF) and prostate specific antigen (PSA). HGF and VEGF are good prognostic indicators of metastatic disease.

The study included 26 men, aged 41 to 72 years, diagnosed with prostate cancer and scheduled for radical prostatectomy. Patients consumed four capsules of a high-concentrate Green Tea supplement until the day before surgery; four capsules are equivalent to about 12 cups of normally brewed concentrated green tea, according to the researchers. The time of study for 25 of the 26 patients ranged from 12 days to 73 days, with a median time of 34.5 days.

Findings showed a significant reduction in serum levels of HGF, VEGF and PSA after treatment, with some patients demonstrating reductions in levels of greater than 30 percent, according to the researchers.

Results of a recent year-long clinical trial conduced by researchers in Italy demonstrated that consumption of green tea polyphenols reduced the risk of developing prostate cancer in men with high-grade prostate intraepithelial neoplasia (HGPIN).

These studies are just the beginning and a lot of work remains to be done, however, the use of tea polyphenols alone or in combination with other compounds currently used for cancer therapy should be explored as an approach to prevent cancer progression and recurrence. Other scientists believe the reduced serum biomarkers of prostate cancer may be attributable to some sort of benefit relating to green tea components.

In collaboration with Columbia University in New York City, the researchers are currently conducting a comparable trial among patients with breast cancer. They also plan to conduct further studies to identify the factors that could explain why some patients responded more dramatically to Polyphenon E than others. Additional controlled clinical trials are being planned to see if combinations of different plant polyphenols were more effective than Polyphenon E alone.

According the leading researchers, there is reasonably good evidence that many cancers are preventable, and our studies using plant-derived substances support the idea that plant compounds found in a healthy diet can play a role in preventing cancer development and progression.