Grenx

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 

Body Weight Loss and Weight Maintenance in Relation to Habitual Caffeine Intake and Green Tea Supplementation.  Obesity Research (2005) ;13:1195–1204. 

Objective: Investigation of the effect of a green tea-caffeine mixture on weight maintenance after body weight loss in moderately obese subjects in relation to habitual caffeine intake.

Research Methods and Procedures: A randomized placebo-controlled double blind parallel trial in 76 overweight and moderately obese subjects, (BMI, 27.5 ± 2.7 kg/m2) Matched for sex, age, BMI, height, body mass, and habitual caffeine intake was conducted. A very low energy diet intervention during 4 weeks was followed by 3 months of weight maintenance (WM); during the WM period, the subjects received a green tea-caffeine mixture (270 mg epigallocatechin gallate; 150 mg caffeine per day) or placebo.

Results: Subjects lost 5.9 ±1.8 (SD) kg (7.0 ± 2.1%) of body weight (p ≥ 0.001). At baseline, satiety was positively, and in women, leptin was inversely, related to subjects’ habitual caffeine consumption (p ≥ 0.01). High caffeine consumers reduced weight, fat mass, and waist circumference more than low caffeine consumers; resting energy expenditure was reduced less and respiratory quotient was reduced more during weight loss (p ≥ 0.01). In the low caffeine consumers, during WM, green tea still reduced body weight, waist, respiratory quotient and body fat, whereas resting energy expenditure was increased compared with a restoration of these variables with placebo (p 0.01). In the high caffeine consumers, no effects of the green tea-caffeine mixture were observed during WM.

Discussion: High caffeine intake was associated with weight loss through thermogenesis and fat oxidation and with suppressed leptin in women. In habitual low caffeine consumers, the green tea-caffeine mixture improved WM, partly through thermogenesis and fat oxidation.

“This was a great article to provide more understanding about the correct amount of green tea to consume to improve weight loss.  However, the greatest insight from this double-blind clinical trial was the difference green tea made in the weight maintenance phase versus high caffeine consumption.”  – Josh Smith