Green Tea Catechins May Slow the Progression of Prostate Cancer

Prostate cancer is the second most common cancer in men, responsible for an estimated 220,000 cancer diagnoses in 2015 alone. Recent cancer research has focused on the possible role botanicals might play in the prevention and treatment of cancer. Researchers at Moffitt Cancer Center conducted a randomized trial to determine the safety and efficacy of green tea catechins in preventing the progression of prostate cancer in men with premalignant lesions.

teaGreen Tea’s Impressive Reputation

Green tea as a possible cancer preventative isn’t new news. We know that 20% of green tea is consumed in Asian countries that boast remarkably low death rates from prostate cancer. We also know that prostate cancer risk increases greatly among Asian men who settle in the United States and forego their green tea drinking habits.

Lab studies show that active compounds called catechins in green tea help to suppress cancer cell growth, motility, and invasion, and trigger cancer cell death. Animal models confirm the cancer-protective benefits of green tea catechins, which help to prevent tumors and stall tumor growth.

Epigallocatechin-3-gallate (EGCG)s the primary catechin in green tea, and is credited with its cancer-fighting powers.

Green Tea and Prostate Cancer

Researchers examined men diagnosed with premalignant prostate cancer lesions: specifically, high-grade intraepithelial neoplasia (HGPIN) or atypical small acinar proliferation (ASAP). Men diagnosed with HGPIN have prostate gland cells that exhibit abnormal patterns (like cancer cells would). Men with ASAP have a collection of lesions on the prostate that cannot be definitively diagnosed as malignant or benign.

The men were randomized into two groups. For one year, 48 men took a placebo pill twice a day, and 49 men took a 200 mgs green tea capsule called Polyphenon E twice a day.  At the end of the year there was no statistical difference in prostate cancer cases diagnosed between the two groups, however, prostate cancer development seemed to be significantly suppressed in the group supplementing with Polyphenon E.

Men diagnosed with only HPIN at the start of the study had a lower combined rate of ASAP and prostate cancer development when taking green tea capsules. The catechins in green tea, primarily EGCG, also lowered prostate-specific antigen (PSA) levels, an indicator of prostate cancer. There were no reported side effects in men taking the 200 mgs capsules.

Another win for green tea…and another reason to drink a cup every day!