Grenx

Green Tea Consumption and Mortality Due to Cardiovascular Disease, Cancer, and All Causes in Japan – The Ohsaki Study.  JAMA, September 13, 2006—Vol 296, No. 10 

Objective To investigate the associations between green tea consumption and allcause and cause-specific mortality.  

Design, Setting, and Participants The Ohsaki National Health Insurance Cohort Study, a population-based, prospective cohort study initiated in 1994 among 40 530 Japanese adults aged 40 to 79 years without history of stroke, coronary heart disease, or cancer at baseline. Participants were followed up for up to 11 years (1995-2005) for all-cause mortality and for up to 7 years (1995-2001) for cause-specific mortality.  

Results Over 11 years of follow-up (follow-up rate, 86.1%) the inverse association with all-cause mortality was stronger in women (P=.03 for interaction with sex). In men, the multivariate hazard ratios of mortality due to all causes associated with different green tea consumption frequencies.  The inverse association with cardiovascular disease mortality was stronger than that with all-cause mortality. This inverse association was also stronger in women (P=.08 for interaction with sex). In women, the multivariate hazard ratios of cardiovascular disease mortality across increasing green tea consumption categories were 1.00, 0.84 (95% CI, 0.63-1.12), 0.69 (95% CI, 0.52-0.93), and 0.69 (95% CI, 0.53-0.90), respectively (P=.004 for trend). Among the types of cardiovascular disease mortality, the strongest inverse association was observed for stroke mortality. In contrast, the hazard ratios of cancer mortality were not significantly different from 1.00 in all green tea categories compared with the lowest-consumption category.

 Conclusion Green tea consumption is associated with reduced mortality due to all causes and due to cardiovascular disease but not with reduced mortality due to cancer. 

“This particular study followed over 40,000 people for 11 years.  Just the sheer size of this study is impressive in and of itself.  What really impressed me was the inverse relationship between the cups of tea and the decrease in cause-specific deaths.  Those who consumed the right amount of green tea antioxidants had the most significant decrease in risk factors.” – Josh Smith

Can green tea do that? A literature review of the clinical evidence.  Preventive Medicine 49 (2009) 83–87 

Objective. Habitual green tea consumption has long been associated with health benefits including chemoprevention and cardiovascular protection. This non-systematic literature review presents the clinical evidence to date. Method. A literature review of peer-reviewed articles on observational and interventional studies was conducted to include green tea, its extract or its purified polyphenol (−)-epigallocatechin-3-gallate (EGCG). Electronic databases searched included PubMed (1966–2009) and the Cochrane Library (Issue 4, 2008). Results: observational studies are inconclusive on the benefits of habitual consumption of green tea in the prevention of most cancers. However, there are trends towards prevention in breast and prostate cancers. Interventional studies have demonstrated reduction in relapses following surgical resection in colorectal adenomas and increased survival rates in epithelial ovarian cancer. Observational studies indicate that green tea may provide protection against hypertension and reduce the risk for stroke, and interventional studies are providing biochemical and physiological evidence. Conclusion. Although the overall clinical evidence is inconclusive, habitual green tea consumption may be providing some level of chemoprevention in prostate and breast cancer. Green tea may also attenuate the risk factors association with the development of atherosclerosis thus reducing the incidence of cardiovascular events and stoke.

“Taking a look at the clinical trials that have been conducted on green tea so far with such technical topics as cancer, hypertension and atherosclerosis, there are great emerging results of daily consumption of green tea.  400 milligrams of EGCG is the amount of antioxidants from green tea that have been identified as the “right amount”.  – Josh Smith 

Objectives To investigate the association between green tea consumption and liver cancer incidence. Methods: We prospectively followed 41,761 Japanese adults aged 40–79 years, without a history of cancer at the baseline or any missing data for green tea consumption frequency. Cox proportional hazards models were used to calculate hazard ratios (HR) with 95% confidence intervals (CI), adjusted for age, alcohol drinking, smoking, the consumption of coffee, vegetables, dairy products, fruit, fish, and soybean. Results Over 9 years of follow-up, among 325,947 accrued person-years, the total incidence of liver cancer was 247 cases. We found that green tea consumption was inversely associated with the incidence of liver cancer. In men, the multivariate-adjusted HRs (95% CIs) for liver cancer incidence with different green tea consumption categories were 1.00 (reference) for\1 cup/day, 0.83 (0.53–1.30) for 1–2 cups/day, 1.11 (0.73–1.68) for 3–4 cups/day, and 0.63 (0.41–0.98) for C5 cups/day (p for trend = 0.11). The corresponding data among women were 1.00 (reference), 0.68 (0.35–1.31), 0.79 (0.44–1.44), 0.50 (0.27–0.90) (p for trend = 0.04). Conclusions Green tea consumption is associated with a reduced risk of liver cancer incidence.

“Following over 40,000 individuals for 9 years has shown a strong association between decreasing the risk of liver cancer and drinking green tea.  Liver cancer is the 6th most common cancer and drinking 5 or more cups of fresh green tea per day significantly decreases the risk of liver cancer.” – Josh Smith