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Green Tea Extract Clinical Studies
A Green Tea Extract High in Catechins Reduces Body Fat and Cardiovascular Risks in Humans:
"Japanese women and men with visceral fat-type obesity were recruited for the trial. After a 2-week diet run-in period, a 12-week doubleblind parallel multicenter trial was performed, in which the subjects ingested green tea containing 583 mg of catechins (catechin group) or 96 mg of catechins (control group) per day. Randomization was stratified by gender and body mass index at each medical institution. The subjects were instructed to maintain their usual dietary intake and normal physical activity.
Results: Data were analyzed using per-protocol samples of 240 subjects (catechin group; n 123, control group; n 117). Decreases in body weight, body mass index, body fat ratio, body fat mass, waist circumference, hip circumference, visceral fat area, and subcutaneous fat area were found to be greater in the catechin group than in the control group."
[Tomonori Nagao et al., A Green Tea Extract High in Catechins Reduces Body Fat and Cardiovascular Risks in Humans, OBESITY, Vol. 15 No. 6 June 2007: 1473-1483.]
Anti-obesity actions of green tea: Possible involvements in modulation of the glucose uptake system and suppression of the adipogenesis-related transcription factors:
"It was confirmed that green tea reduced adipose tissue weight without any change in body weight, other tissue weights, and food and water intakes. Green tea also significantly reduced the plasma levels of cholesterols and free fatty acids. Certain catechins existed in the plasma at 0.24 M under our experimental conditions, though most of them existed as conjugated forms. For mechanisms of the anti-obesity actions, green tea significantly reduced glucose uptake accompanied by a decrease in translocation of glucose transporter 4 (GLUT4) in adipose tissue..."
[H. Ashida et al., Anti-obesity actions of green tea: Possible involvements in modulation of the glucose uptake system and suppression of the adipogenesis-related transcription factors, BioFactors, Volume 22, Issues 1-4 : 135-140, (2004).]
Effects of Catechin Enriched Green Tea on Body Composition
"We observed a decrease in estimated intraabdominal fat (IAF) area of 5.6 cm2 in the GT3 group. In addition, we found decreases of 1.9 cm in waist circumference and 1.2 kg body weight in the GT3 group vs. C (P < 0.05). We also observed reductions in total body fat (GT2, 0.7 kg, P < 0.05) and body fat % (GT1, 0.6%, P < 0.05). We conclude that consumption of two servings of an extra high catechin GT leads to improvements in body composition and reduces abdominal fatness in moderately overweight Chinese subjects."
[Hongqiang Wang et al., Effects of Catechin Enriched Green Tea on Body Composition, Obesity Vol. 18 :773-779 (2010).]
Efficiency of a green tea extract rich in catechin polyphenols and caffeine in increasing 24-h energy expenditure and fat oxidation in humans
"This finding with the green tea extract is even more remarkable when compared with data indicating that caffeine ingestion alone, even at doses as high as 1000 mg/d, had no significant effect on the RQ during the diurnal or nocturnal period (19). Third, stimulation of thermogenesis and fat oxidation by the green tea extract was not accompanied by an increase in heart rate. In this respect, the green tea extract is distinct from sympathomimetic drugs, whose use as antiobesity thermogenic agents is limited by their adverse cardiovascular effects..."
[Abdul G. Dulloo et al., Efficacy of a green tea extract rich in catechin polyphenols and caffeine in increasing 24-h energy expenditure and fat oxidation in humans, The American Journal of Clinical Nutrition, 70:1040–5 (1999).]
Green Tea and Weight Loss
"Research on green tea and its components shows an impact on obesity and weight gain in both laboratory animals and human subjects. Green tea has an impact on food intake, body weight, and body fat, and cholesterol, triglycerides, and glucose levels. With the high rates of overweight and obesity seen in the US, green tea could prove to be a valuable natural treatment option."
[H. Roy PhD, Green Tea and Weight Loss, Pennington Nutrition Series Vol. 9 (2007), at pbrc.edu/division-of-education /pdf/pns/PNS_Green_Tea.pdf.]
Green Tea Catechin Consumption Enhances Exercise-Induced Abdominal Fat Loss in Overweight and Obese Adults
"The catechin beverage employed was well tolerated. The frequencies of adverse events overall and for the major body systems, including abnormal laboratory values, were similar for participants in the catechin and control beverage groups. In summary, the findings of this study suggest that consumption of a beverage containing green tea catechins (625 mg/d) may enhance exercise-induced loss of abdominal fat and improve circulating FFA and TG levels."
[Kevin C. Maki et al., Green Tea Catechin Consumption Enhances Exercise-Induced Abdominal Fat Loss in Overweight and Obese Adults, The Journal of Nutrition and Disease: 264-270 (2009).]
Green tea catechins linked to weight loss: Study
"At the end of the study period, people in the catechin group were found to have lost more body weight compared to the control group (P = 0.079). There were no significant differences between the two groups in changes in waist circumference or fat mass. However, both total abdominal fat area (P = 0.013) and abdominal subcutaneous fat area (P = 0.019) had decreased more in the catechin group."
[Lorraine Heller, Green tea catechins linked to weight loss: Study, at http://www.nutraingredients. com/Research/Green-tea-catechins-linked-to-weight-loss-Study.