Green tea should be a part of everyday health for men. That's because green tea contains compounds that are important for maintaining men's health (including preventing prostate cancer), protecting against heart disease (the number one killer of men), and fighting overweight/obesity (72.3 percent of men), among other benefits. (1)
Green tea's medicinal powers are in catechins, potent antioxidants that have demonstrated a variety of health-enhancing properties. Among the several different types of catechins, the most powerful is epigallocatechin gallate, or EGCG.
In a study published in Cancer Prevention Research, for example, investigators reported that antioxidants in green tea, mainly EGCG, significantly reduced the levels of prostate specific antigen (PSA) and two other indicators for prostate cancer in men who had the disease. (2)
Catechins may also benefit men who have pre-cancerous prostate lesions called prostate intraepithelial neoplasia (PIN). Men who have PIN have a high risk of developing "full-on" prostate cancer, so they naturally are interested in ways to reduce that risk. One possibility may be EGCG, according to a study published in Cancer Research. Sixty men who had high-grade PIN received either three 200-mg capsules of catechins daily or a placebo. After one year, only one tumor was found among the 30 treated men compared with nine discovered in the 30 controls. (3)
Numerous studies involving large populations of men have shown that those who drink green tea regularly are less likely to develop prostate cancer than men who avoid the tea. (4) Exactly how much green tea a man should drink to protect his prostate is not clear, but the results of a few studies offer some guidelines.
One large study followed the green tea drinking habits of 49,920 men aged 40 to 69 for 10 years. Men who enjoyed five or more cups daily had a reduced risk of advanced prostate cancer when compared with men who drank less than one cup daily. (5) If five cups sounds like too much, another study found that men who drank more than three cups daily were less likely to get the disease. (6)
How does green tea fight prostate cancer? Some scientists say it interferes with the actions of an enzyme that promotes cancer, slows the growth of prostate cancer cells, and prompts them to commit suicide (apoptosis). (7) Catechins can also interfere with the activity of COX-2, an enzyme that accumulates in prostate cancer tissues. (8) The popular COX-2 inhibitor, celecoxib (Celebrex), can slow the growth of prostate cancer in animals. However, at least one study showed EGCG was nearly as effective as COX-2 inhibitors in slowing the growth of prostate cancer. (9)
Green tea may also protect the heart and circulation. Decaffeinated green tea significantly reduced cholesterol and triglyceride concentrations in lab animals in one study, while another noted that drinking several cups of green tea every two to three days reduced stroke by 50 percent. (Tanabe 08) Experts believe the antioxidants in green tea improve the flexibility of blood vessels, making them less likely to become blocked. (10)
In an Oklahoma State University study, green tea as a beverage (four cups daily) and as a supplement (two capsules daily) for eight weeks significantly decreased body weight and body mass index in obese patients when compared with controls. (11) More evidence was seen in overweight men who took 300 mg EGCG daily for two days. They experienced an increase in fat oxidation, indicating that the catechin contributes to the antiobesity effect of green tea. (12)
If the thought of going from zero to three to five cups of green tea daily does not appeal to you can make a green tea smoothie. Brewing time has a major impact on the final catechin content, so steep green tea leaves or powder (skip tea bags) for a minimum of 15 minutes. Japanese green teas tend to be the most potent when it comes to catechin levels.
Given the fact that soda is killing the nation promoting healthy drinking choices for all is more critical than ever.
Read more on green tea, red wine and prostate cancer
And click here for information on white tea and prostate cancer
Craig Cooper is the founder of CooperativeHealth, The Prostate Cancer Institute and the men's health website www.prostate.net. Become a fan of www.prostate.net on Facebook and get men's health updates on Twitter (http://twitter.com/Prostatenet). Also, check out Craig's "Healthy Living for Men" blog.
Sources
1.NIH, "Overweight and Obesity Statistics," http://win.niddk.nih.gov/publications/PDFs/stat904z.pdf ; Heron MP et al. Deaths: Final data for 2006. National Vital Statistics Reports; Vol. 57 No. 14. Hyattsville, MD: National Center for Health Statistics. 2009; and Chacko SM et al. Beneficial effects of green tea: a literature review. Chinese Med 2010 Apr 6; 5:13
2.McLarty J et al. Tea polyphenols decrease serum levels of prostate-specific antigen, hepatocye growth factor, and vascular endothelial growth factor in prostate cancer patients. Cancer Prev Res 2009 Jun 19; online 10.1158/1940-6207.
3.Bettuzzi S et al. Chemoprevention of human prostate cancer by oral administration of green tea catechins in volunteers with high-grade prostate intraepithelial neoplasia. Cancer Res 2006; 66(2):1234-40.
4.Heilbrun LK et al. Black tea consumption and cancer risk: a prospective study. Br J Cancer 1986; 54:677-83; and Jain MG et al. Alcohol and other beverage use and prostate cancer risk among Canadian Men. Intl J Cancer 1998; 78(6):707-11.
5.Kurahashi N et al. Green tea consumption and prostate cancer risk in Japanese men: a prospective study. Am J Epidemiol 2008; 167(1): 71-77.
6.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.
7.Gupta S et al. Prostate cancer chemoprevention by green tea. Cancer Research 1999; 59(9):2115-20; and 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. Toxicol Appl Pharmacol 2000; 164(1):82-90.
8.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.
9.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. Clin Cancer Res 2007; 13:1611-19.
10.Tanabe N et al. Consumption of green and roasted teas and the risk of stroke incidence: results from the Tokamachi-Nakasato cohort study in Japan. Int J Epidemiol 2008 Oct; 37(5): 1030-40
11.Basu A et al. Green tea supplementation affects body weight, lipids, and lipid peroxidation in obese subjects with metabolic syndrome. J Am Coll Nutr 2010 Feb; 29(1): 31-40
12.Boschmann M, Thielecke F. The effects of epigallocatechin-3-gallate on thermogenesis and fat oxidation in obese men: a pilot study. J Am Coll Nutr 2007; 26(4):389S-95S