Green tea has been recognized as a health-promoting tonic for centuries. In China it has been used by emperors and monks as a way to promote longevity, energy, and vitality.
In recent years, more and more research has been published demonstrating an impressive array of health benefits from heart disease prevention to cancer treatment.
Aside from the reported therapeutic benefits associated associated with green tea, green tea has been touted as a potent weight loss aid. In this article, we will distil the research surrounding the weight loss benefits of green tea and lay out a strategy to choose and supplement with this impressive natural compound.
What’s In Green Tea?
Green tea contains hundreds of antioxidants and plant compounds with potential to impact the health and function of the body. Of these ingredients, a family of plant compounds called catechins have been of particular interest to researchers.
Although all of the catechins seem to have activity, and thus health benefit, researchers have focused on one of the most powerful catechins called epigallocatechin-3-gallate…EGCG for short.
Does Green Tea Promote Weight Loss?
The research on the benefits of green tea for weight loss have been far from stellar, however, there is more and more research being published each year that may improve upon the knowledge base that we currently have. Based on the data that we have available, it does appear that green tea enhances the body’s ability to access fat cells and burn it away.
In one study, researchers surveyed over 1200 men and women and discovered that those who habitually consumed tea (primarily green tea and oolong tea) for more than 10 years enjoyed a body fat percent that was 19.6% lower than the non-tea drinkers. In addition, the tea drinkers showed a 2.1% lower waist to hip ratio (Obesity Research, 11:1088-1095,2003).
Such a study gives us insight into a possible effect, unfortunately, based on observational research we can’t know if it is correlation or causation. In other words, do tea drinkers have lower body fat because green tea promotes weight loss or are those who drink tea simply more health conscious and therefore fitter folks?
One study, published in the American Journal of Clinical Nutrition, gave one group of people an oolong tea containing 690 mg of catechins and another group the same tea with the catechins removed. After 12 weeks, the catechin group had significantly lower body fat, waist circumferences, and body weight compared to the low-catechin group. (Am J Clin Nutr;81:122-129,2005)
Super-Charged Green Tea Extract
The research published to date has shown that green tea has some impact on weight loss; unfortunately, these results are nothing to write home about. For example, a 1 pound weight loss in 45 days is probably not going to have you singing green tea’s praises on Facebook.
Researchers have hypothesized that because catechins are poorly absorbed, not enough is getting to the cell to spark the type of metabolism that we want to see.
To improve the absorptions of the catechins in green tea, researchers in Italy developed a formulation where the catechins are bound to phospholipids for improved absorption.
One study on the new, improved green tea product split 100 significantly overweight subjects into two groups. Both groups were placed on a low-calorie diet, one group was give 150 mg twice daily of the new green tea phytosome while the other group was given a placebo. At the end of the 90-day study, the green tea phytosome group had lost 30.1 pounds while the placebo group lost just 9.9 pounds. Now that sounds much more impressive! In addition, the green tea phytosome group lost twice as much around the middle as the placebo! (Intege Nutr. 2008;11(2):1-14)
How Does Green Tea Work?
In one study, 10 men were given one of three treatments. Group one was given green tea, group two was given caffeine only, and group three was given a placebo pill. The men’s metabolic rate was then monitored over a 24 hour period. Green tea performed the best, increasing metabolism by 4.5% over the placebo and 3.2 % over caffeine only. This may not seem like much, but over a month and a half period this could result in 1 pound of fat loss in the average person! (Am J Clin Nutr, 49: 44- 50, 1989)
Green tea appears to impact metabolism by decreasing the breakdown of noradrenaline in the body, a potent stimulant of fat burning. By preventing the metabolism of noradrenaline, people may keep the metabolic fires burning a bit longer each day. Although, this research is not enough to prove the fat loss benefits of green tea, it adds to the argument in favor of green tea.
Besides the benefit to metabolism, green tea also appears to inhibit or slow the digestion of fat in the diet by neutralizing lipase, an enzyme needed for fat digestion and absorption. Although this research is in its infancy, we will continue to watch to see if more data proves this fat-blocking effect.
How Much Caffeine Is In Green Tea?
The average cup of green tea has between 15-25 mg of caffeine in a 150 ml cup; compared to coffee’s 80-115 mg per 150 mls, green tea has far less.
Caffeine is a stimulant and has been recognized as a fat loss aid, however, green tea’s fat burning effects seem to occur independent of the caffeine because even decaffeinated green tea seems to promote fat loss!
How To Supplement With Green Tea?
There are many green tea supplements on the market, however, the one that seems to be the most powerful for fat loss is the green tea phytosome discussed earlier. The product used in the research study described earlier is called TeaSlender and the recommended dose is 150 mg twice daily. If you use a standard green tea supplement, the research suggests that 270 mg per day of EGCG should suffice.
It is important to note that EGCG is one compound found in green tea, so you want to make sure that the product that you use is standardized to EGCG and then dose according the the EGCG content. For example, if a product say contains 700 mg of green tea standardized to 45% EGCG, then it contains 315 mg of EGCG, which should be plenty. If, however, the formula says it contains 500 mg of green tea standardized to 20% EGCG, then you will need to take 3 capsules daily to achieve the best result.
References:
1. Wu,Chih-hsing, et al, Relationship among habitual tea consumption, percent body fat, and body fat distribution, Obesity Research, 11:1088-1095,2003
2. Nagao, T., et al, Ingestion of a tea rich in catechins leads to a reduction in body fat and maldondialdehyde-modified LDL in men, Am J Clin Nutr; 81: 122-129, 2005
3. Dulloo AG, Normal caffeine consumption: influence on thermogenesis and daily energy expenditure in lean and postobese human volunteers, Am J Clin Nutr, 49: 44- 50, 1989