About Green Tea with ECGC

Next to water, the most widely consumed beverage in the world is tea, and with good reason!  For thousands of years, drinking tea was thought to contribute to a long and healthy life, and green tea, especially, was thought to benefit the drinker in a multitude of ways.[1]  Of the three main kinds of tea (black, oolong, and green), green tea contains the highest concentration of anti-oxidants and health enhancing substances because green tea leaves are not fermented like those of black or oolong varieties.  This is also why green tea contains so much less caffeine than black tea. 

Science has long been interested in how green tea can be so beneficial to our health and researchers believe that the active ingredient responsible for the majority of green tea’s healthy benefits is the polyphenol, or catechin, epigallocatechin gallate, or EGCG.[2]  One of the most exciting discoveries in the field of weight loss and weight management is that EGCG appears to stimulate thermogenesis, which in turn increases the amount of calories a person burns both while active and while at rest.[3]  The studies and review articles discussed below shed light on the wide range of research evidence demonstrating the beneficial role that green tea, and especially EGCG, can play in reaching weight management goals, though it is important to keep in mind the vital role that a healthy diet and regular exercise play in attaining such goals.

Firstly, a study based in Taiwan examining how various lifestyle factors contribute to good health found a link between green tea drinkers and healthy body weight, suggesting that those subjects who drank green tea regularly, and on a long-term basis, had lower body fat percentages and therefore, healthier body weight.[4]

Now, several studies have attempted to show how EGCG works.  The more common explanation is that thermogenesis is responsible for the results seen in studies.  For example, in a study published in 2002 from France, researchers reported that after taking a green tea extract containing EGCG, for three months, subjects experienced a reduction in weight, and a reduction in waist circumference.  These authors concluded that EGCG’s stimulation of thermogenesis played an important role in their outcomes.[5]

The results of laboratory studies conducted by researchers at Rutgers, the State University of New Jersey, also found that EGCG appeared to play a key role in weight loss and was associated with the numerous health benefits linked to achieving a healthy weight.[6]

Two Japanese studies explored these benefits in greater detail and measured the effect of taking EGCG on weight and body composition.  The first study compared how a low-dose and high-dose supplement containing tea catechins affected 23 healthy men and the results showed that after twelve weeks, both groups had decreased total body weight and body mass index, but the high-dose group much more so.  In light of these findings, the authors suggest that tea catechins, like EGCG appear to substantially support weight loss.[7]

The second Japanese study similarly found that catechins, like EGCG, had a statistically significant impact on many measures contributing to weight loss and healthy body composition.  The study consisted of 80 subjects who took either an EGCG supplement or a placebo for 12 weeks.  Subjects recorded their energy intake and daily activity for several days at the beginning and end of the study for comparison purposes.  Factors like weight, body mass index, waist circumference, hip circumference, and body fat percentage were measured and compared at regular intervals throughout the study.  Participants taking EGCG showed reductions in nearly all areas measured and the authors recommend the consumption of EGCG to maintain a healthy body weight.[8]

Moreover, a Polish study demonstrated impressive results when combining a diet and exercise regimen with a supplement containing EGCG.  For this study, 98 subjects were divided into two groups.  For twelve weeks, each group maintained a reduced-calorie diet and participated in an exercise program.  In addition, one group took a supplement containing EGCG with their meals and the other took a placebo.  While both groups experienced weight loss, the group taking the EGCG showed a more significant reduction in body fat and also a more positive change in the body composition improvement index score.[9]  These results demonstrate the beneficial role EGCG can play in the achievement of a healthy weight when combined with a healthy diet and exercise. 

In order to more closely examine to what degree thermogenesis is stimulated by EGCG, a Swiss study examined the energy expenditure of 32 subjects using a calorimeter chamber.  The study consisted of three phases.  In Phase 1, each subject spent 23 hours in the calorimeter chamber to measure energy expenditure (the amount of calories burned) at the start of the study.  For Phase 2, subjects followed a fairly strict dietary plan for three days in order to eliminate any influence calorie intake might have on test results.  A key part of the plan was the regular consumption of a beverage containing either green tea extract, or a placebo.  At the end of the three-day period, subjects’ energy expenditure was measured in the calorimeter chamber a second time.  Finally, for Phase 3, the process was repeated, but subjects who had received EGCG received a placebo and vice versa.  All three calorimeter chamber measurements were compared and the results revealed that after three days of consuming the green tea beverage, subjects’ energy expenditure during the 23 hours immediately following the testing phase, showed a modest increase in comparison to baseline and placebo results.[10]  As in previous studies, the authors suggest that compounds in green tea, such as EGCG, support healthy weight maintenance by increasing the amount of calories participants burned in the course of a day.

Finally, in a review article compiling research studies which examine the effect of certain foods on weight loss and weight management, a researcher from Columbia University found a fairly unanimous consensus among authors of the included studies.  Whether these dealt with taking a supplement with EGCG or drinking several cups of green tea, if the studies were short-term or long-term in duration, the general conclusion was that EGCG is beneficial for maintaining a healthy body weight, particularly in combination with a healthy diet and regular exercise.[11]

Achieving and maintaining a healthy weight is one of the most important things we can do for our overall health.  Of course, eating a healthy, balanced diet and staying active by exercising or engaging in regular physical activity cannot be underestimated.  These are crucial elements in meeting our weight loss goals.  Nevertheless, the abundant evidence demonstrating the efficacy of EGCG in weight management mean that green tea with EGCG can be a valuable supplemental tool when added to our arsenal in order to achieve these weight loss goals. 

[1] “Green Tea,” University of Maryland Medical Center, last modified on October 14, 2011, http://www.umm.edu/altmed/articles/green-tea-000255.htm.

[2] Ronald Hoffman, “EGCG – potent extract of green tea,” Dr. Hoffman, Accessed April 24, 2012, http://www.drhoffman.com/page.cfm/118.

[3] Q. Shixian, et al., “Green tea extract thermogenesis-induced weight loss by epigallocatechin gallate inhibition of catechol-o-methyltransferase,” Journal of Medicinal Food 9, No. 4 (2006): 451-458.

[4] Chih-Hsing Wu, et al., “Relationship among habitual tea consumption, percent body fat, and body fat distribution,” Obesity Research 11, (2003): 1088-1095.

[5] P. Chantre & D. Lairon, “Recent findings of green tea extract AR25 (Exolise) and its activity for the treatment of obesity,” Phytomedicine 9, No. 1 (2002): 3-8.

[6] Muosumi Bose, et al., “The major green tea pholyphenol (-)-Epigallocatechin-3-Gallate inhibits obesity, metabolic syndrome, and fatty liver disease in high-fat-fed mice,” Journal of Nutrition 138, No. 9 (2008): 1677-1683.

[7] Tadashi Hase, et al., “Anti-obesity effects of tea catechins in humans,” Journal of Oleo Science 50, No. 7 (2001): 599

[8] Takashi Tsuchida, Horshige Itakura & Haruo Nakamura, “Reduction of body fat in humans by long-term ingestion of catechins,” Progress in Medicine 22, No. 9 (2002): 2189-2203.

[9] T. Opala, et al., “Efficacy of 12 weeks supplementation of a botanical extract-based weight loss formula on body weight, body composition and blood chemistry in healthy, overweight subjects – a randomized double-blind placebo-controlled clinical trial,” European Journal of Medical Research 11, (2006): 343-350.

[10] Servane Rudelle, et al., “Effect of a thermogenic beverage on 24-hour energy metabolism in humans,” Obesity 15, No. 2 (2006): 349-355.

[11] Marie-Pierre St-Onge, “Dietary fats, teas, dairy, and nuts: potential functional foods for weight control?” American Journal of Clinical Nutrition 81, No. 1 (2005): 7-15.

*These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure or prevent any disease, including obesity. Consult a doctor before starting any weight loss program. Use with a healthy diet and regular exercise. Follow label directions carefully.