Green Tea Health Benefits
Green tea health benefits are associated with its antioxidant content and include an ability to enhance the immune system, fight prostate cancer, treat prostatitis, reduce DHT levels, and possibly prevent BPH. The medicinal powers of green tea (Camillia sinesis) have been attributed to catechins, potent antioxidants that have an array of health-promoting properties
Green tea health benefits, associated with its catechins, are an important tool in the quest for prostate health. Although there are several different kinds of catechins, the most powerful is epigallocatechin gallate, EGCG.
Green Tea, High Grade PIN, and BPH
Catechins may benefit men who have pre-cancerous prostate lesions (prostate intraepithelial neoplasia, or PIN), a condition that indicates a high risk of developing “full-on” prostate cancer. Studies indicate that 30% of men who have a high-grade PIN go on to develop prostate cancer within one year after repeated biopsy. In a 2006 study published in Cancer Research, 60 men who had high-grade PIN participated in the double-blind, placebo-controlled study. (Bettuzzi 2006) Men in the intervention group received three 200-mg capsules of catechins daily. After one year, only one tumor was diagnosed among the 30 men who took catechins, compared with nine cancers found among the 30 controls. The researchers also noticed that the men who took the catechins had reduced lower urinary tract symptoms, which suggests catechins may be helpful in managing symptoms of BPH.
Green Tea Health Benefits and Prostate Cancer
Green tea health benefits appear to extend to prostate cancer. Studies of large populations of men have shown that those who consume green tea regularly are less likely to develop prostate cancer than men who shun the beverage. (Heilbrun 1986; Jain 1998) In other studies, researchers found that the risk of prostate cancer decreased proportionally as the amount, frequency, and duration of green tea consumption increased. (Jian 2004) Notably, men who drank more than three cups of green tea daily showed a reduced risk of prostate cancer. A large study evaluated the green tea drinking habits of 49,920 men aged 40 to 69 who were followed for at least 10 years. The investigators found that men who consumed five or more cups of green tea daily had a reduced risk of advanced prostate cancer when compared with men who drank less than one cup daily. (Kurahashi 2008)
Research into green tea health benefits and prostate cancer suggests that green tea:
- Interferes with the activity of an enzyme called ortnithine decarboxylase, which plays a role in the “birth” of prostate cancer (Gupta 1999)
- Slows the growth of human prostate cancer cells and prompts them to “commit suicide” (apoptosis) (Gupta 2000)
- Encourages the repair of damaged DNA that might otherwise promote cancer growth (Butt 2009)
- Inhibits the activity of an enzyme called COX-2, which accumulates in prostate cancer tissue and is involved in the prostate cancer process. (Hussein 2005). Research shows that prescription medications called COX-2 inhibitors, such as celecoxib (Celebrex) have the ability to slow the growth of prostate cancer in animal models. However, a recent study published in Clinical Cancer Research shows that the EGCG found in green tea was nearly as effective as COX-2 inhibitors in slowing the growth of prostate cancer. (Adhami 2007)
- Stimulates the activity of certain immune system cells that fight tumors. (Butt 2009)
- Has antioxidant powers that contribute to its ability to reduce levels of DHT (dihydrotestosterone), a hormone that raises a man’s risk of developing BPH and prostate cancer.
In a study published in the journal Cancer Prevention Research in June 2009, researchers reported that green tea polyphenols, primarily EGCG, significantly reduced the levels of PSA and two biomarkers for prostate cancer. The study included 26 men who had prostate cancer and who were scheduled for radical prostatectomy. (McLarty 2009)
Green Tea Health Benefits and Prostatitis
Green tea health benefits also extend to prostatitis. In a rat model of chronic bacterial prostatitis, the animals were given either placebo, catechins, ciprofloxacin, or catechins plus ciprofloxacin. The catechins group alone showed modest improvements in inflammation and bacterial growth compared with the placebo group, but the combination of catechins and ciprofloxacin demonstrated significant improvements when compared with placebo. (Lee 2005)
Another study of green tea health benefits and prostatitis was published in the Journal of Infection and Chemotherapy in 2010. Researchers used rat models of chronic prostatitis and found that nanocatechins (catechins altered using nanotechnology) had more effective anti-inflammatory and antimicrobial effects on rat chronic prostatitis than “normal” catechins because the body was able to absorb them better. (Yoon 2010)
Choosing Green Tea
The amount of catechin in green tea varies depending on where the tea is cultivated, the diversity of plants used, the harvest season, and how it is processed. Generally, Japanese green tea has a greater EGCG content than does Chinese tea, but within these two categories there are differences as well. According to an analysis of EGCG content in different types of green tea conducted by the authors of Foods to Fight Cancer, Sencha uchiyama (a Japanese green tea) is superior to a dozen other Japanese and Chinese green tea varieties. (Beliveau 2007) Other Japanese green teas that rank high in EGCG content include Gyokuro, Sencha, and Matcha. Chinese green tea that is roughly equivalent to Matcha is pito chun emperor; other Chinese green teas that have a lesser amount of EGCG than Matcha and Pilo chun emperor are Hunnan, Yuzan, Paimutan, Meng ding, Lung chin, Dong ding, Pou chong, and Tikuan yin. Thus there may be some variation in the level of green tea health benefits based on EGCG content.
Dr. Geo Espinosa, N.D., L.Ac, CNS, RH (AHG)
Adhami VM et al. Combined inhibitory effects of green tea polyphenols and selective cyclooxygenase-2 inhibitors on the growth of human prostate cancer cells both in vitro and in vivo. Clinical Cancer Research 2007; 13:1611-19.
Beliveau R, Gingras D. Foods to Fight Cancer. New York/London: DK Publishing, 2007.
Bettuzzi S et al. Chemoprevention of human prostate cancer by oral administration of green tea catechins in volunteers with high-grade prostate intraepithelial neoplasia: a preliminary report from a one-year proof-of-principle study. Cancer Research 2006; 66(2):1234-40.
Butt MS, Sultan MT. Green tea: nature’s defense against malignancies. Crit Rev Food Sci Nutr 2009; 49(5):463-73.
Gupta S et al. Prostate cancer chemoprevention by green tea: in vitro and in vivo inhibition of testosterone-mediated induction of ornithine decarboxylase. Cancer Research 1999; 59(9):2115-20.
Gupta S et al. Growth inhibition, cell-cycle dysregulation, and induction of apoptosis by green tea constituent (-)-epigallocatechin-3-gallate in androgen-sensitive and androgen-insensitive human prostate carcinoma cells. Toxicology & Applied Pharmacology 2000; 164(1):82-90.
Heilbrun LK et al. Black tea consumption and cancer risk: a prospective study. Br J Cancer 1986; 54:677-83.
Hussain T et al. Green tea constituent epigallocatechin-3-gallate selectively inhibits COX-2 without affecting COX-1 expression in human prostate carcinoma cells. Intl J Cancer 2005; 113(4):660-69.
Jain MG et al. Alcohol and other beverage use and prostate cancer risk among Canadian Men. Intl J Cancer 1998; 78(6):707-11.
Jian L et al. Protective effect of green tea against prostate cancer: a case-control study in southeast China. Intl J Cancer 2004; 108(1):130-35.
Kurahashi N et al for the JPHC Study Group. Green tea consumption and prostate cancer risk in Japanese men: a prospective study. Am J Epidemiol 2008; 167(1): 71-77.
Lee YS et al. Synergistic effect between catechin and ciprofloxacin on chronic bacterial prostatitis rat model. Int J Urol 2005 Apr; 12(4): 383-89
McLarty J et al. Tea polyphenols decrease serum levels of prostate-specific antigen, hepatocyte growth factor, and vascular endothelial growth factor in prostate cancer patients and inhibit production of hepatocyte growth factor and vascular endothelial growth factor in vitro. Cancer Prev Res 2009 Jun 19; online 10.1158/1940-6207.
University of Maryland Medical Center, information on green tea health benefits:
Yoon BI et al. Anti-inflammatory and antimicrobial effects of nanocatechin in a chronic bacterial prostatitis rat model. J Infect Chemother 2010 Aug 7