Effects of encapsulated green tea and Guarana extracts containing a mixture of epigallocatechin-3-gallate and caffeine on 24 h energy expenditure and

Sonia Be´rube´-Parent, Catherine Pelletier, Jean Dore´ and Angelo Tremblay*

Division of Kinesiology, Laval University, Ste-Foy, Que´bec, Canada, G1K 7P4
(Received 7 October 2004 – Revised 8 April 2005 – Accepted 11 April 2005)

It has been reported that green tea has a thermogenic effect, due to its caffeine content and probably also to the catechin, epigallocatechin-3-gallate (EGCG).The main aim of the present study was to compare the effect of a mixture of green tea and Guarana extracts containing a fixed dose of caffeine and variable doses of EGCG on 24 h energy expenditure and fat oxidation. Fourteen subjects took part to this randomized, placebo-controlled, double-blind, cross-over study. Each subject was tested five times in a metabolic chamber to measure 24 h energy expenditure, substrate oxidation and blood pressure. During each stay, the subjects ingested a capsule of placebo or capsules containing 200mg caffeine and a variable dose of EGCG (90, 200, 300 or 400 mg) three times daily, 30 min before standardized meals. Twenty-four hour energy expenditure increased significantly by about 750 kJ with all EGCG–caffeine mixtures compared with placebo. No effect of the EGCG–caffeine mixture was observed for lipid oxidation. Systolic and diastolic blood pressure increased by about 7 and 5 mmHg, respectively, with the EGCG–caffeine mixtures compared with placebo. This increase was significant only for 24 h diastolic blood pressure. The main finding of the study was the increase in 24 h energy expenditure with the EGCG–caffeine mixtures. However, this increase was similar with all doses of EGCG in the mixtures.

Green tea is one of the most widely consumed beverages in the world and is currently perceived as a healthy drink. Green tea contains a large amount of catechins (30 to 42% dry weight), a group of very active flavonoids (Yang & Landau, 2000; Dusfresne & Farnworth, 2001). The catechins, which are antioxidants, have been attributed beneficial health properties such as protection against CVD and certain types of cancer. Also, some attention has recently been given to the possible beneficial effects of green tea on the treatment of obesity. The catechins epicatechin, epicatechin-3-gallate, epigallocatechin and epigallocatechin-3-gallate (EGCG) are the major components of green tea leaves. EGCG is the most abundant catechin and has received the most attention (Yang & Landau, 2000). Caffeine represents approximately 3 to 5% of the dry weight of green tea (Yang & Landau, 2000; Dusfresne & Farnworth, 2001). Caffeine consumption has been related to an increase in energy expenditure (Astrup et al. 1990; Dulloo et al. 1989), which explains why the thermogenic effect of green tea is generally attributed to its caffeine content. However, Dulloo et al. (2000) reported that, in rats, a green tea extract stimulates brown adipose tissue thermogenesis to a much greater extent than that which can be attributed to its caffeine content per se. In another study, ten healthy men were assigned to three treatments: green tea extract containing 50 mg caffeine and 90 mg EGCG, caffeine (50 mg) or placebo. A capsule of green tea extract, caffeine or placebo was taken with each meal. Ingestion of green tea extract increased 24 h energy expenditure by 4% (328 kJ), reflecting its stimulatory effect on thermogenesis. The study also found a reduction in RQ during the green tea extract treatment, suggesting an increase in fat oxidation (Dulloo et al. 1999). On the other hand, the caffeine treatment did not produce any effect on these variables. In addition, the thermogenesis and fat oxidation stimulation obtained in that study was not accompanied by an increase in heart rate that may be seen when patients are treated with sympathomimetic anti-obesity drugs. Since obese individuals are at greater risk of developing cardiac problems, the increase in heart rate and blood pressure frequently observed when treated with sympathomimetic agents is a matter of concern for health professionals. In this context, the green tea extract and caffeine mixture seems to have potential as an effective alternative to these anti-obesity drugs. Since it was shown that a total daily dose of 270 mg (3 £ 90 mg) EGCG combined with a total daily dose of 150 mg (3 £ 50 mg) caffeine has the potential to produce an
increase in energy expenditure, augmenting the amount of caffeine in the blend could possibly accentuate this increase. Moreover, augmenting the amount of EGCG in the green tea extract mixture may produce a greater increase in energy expenditure. If so, the most effective level of EGCG to use in combination with caffeine to produce a significant increase in energy expenditure and fat oxidation without producing negative cardio-stimulatory side-effects would deserve specific investigation.

Green Tea Cheesecake

Prep Time:
15 Min

Cook Time:
25 Min

Ready In:
1 Hr 40 Min

Ingredients

• 2 (8 ounce) containers fat-free cream cheese, softened
• 2 eggs, beaten
• 3/4 cup white sugar
• 1 tablespoon green tea powder
• 2 teaspoons vanilla extract
• 1 (9 inch) prepared graham cracker pie crust

Directions

1. Preheat oven to 350 degrees F (175 degrees C).
2. In a large bowl, beat together the cream cheese and sugar until smooth. Mix in the green tea powder, eggs, and vanilla extract until lightly and creamy; pour into the prepared crust.
3. Bake in preheated oven for 25 minutes, or until the center jiggles evenly when the cake is shaken lightly. Refrigerate 1 hour before serving.

Green Tea Extract May Treat Uterine Fibroids

By Bill Hendrick
WebMD Health News

Reviewed By Louise Chang, MD

Jan. 26, 2010 -- An extract from green tea may be useful in treating uterine fibroids, a condition that affects 25%-30% of U.S. women, new research indicates.

Fibroids of the uterus, a condition called uterine leiomyoma, can be debilitating, leading to excessive vaginal bleeding, anemia, and fatigue.

Dong Zhang, MD, and colleagues from Meharry Medical College in Nashville, Tenn., say they've found that an extract of green tea could kill uterine fibroid cells in test tube studies and reduce the size and weight of fibroids in mice.

Their work is published this week in the American Journal of Obstetrics and Gynecology.

The researchers injected 20 mice with fibroid cells. Ten mice were given epigallocatechin gallate (EGCG) mixed with their water, and 10 mice were given plain water. EGCG is a polyphenol in green tea and is a compound found in vegetables and fruits.

The mice were followed for up to eight weeks. At both four weeks and eight weeks after treatment, fibroid growths were smaller and weighed less. The researchers note that one mouse in the EGCG group had no tumor seen at the end of eight weeks.

In test tube studies with rodent fibroid cells, cells treated with EGCG grew more slowly and were smaller after 48-72 hours. EGCG also prompted fibroid cell death. The researchers write that it is "highly encouraging that, in our work, a relatively modest dose of EGCG ... that was delivered in drinking water was successful in inducing a dramatic and sustained reduction in fibroid tumor size up to eight weeks after treatment."

The researchers say their study suggests that EGCG "might be particularly useful for long-term use in women with a low fibroid tumor burden to arrest tumor progression and avoid the development of severe symptoms that necessitate major surgery."

Ayman Al-Hendy, MD, PhD director of Clinical Research at Meharry, says in the news release that women who suffer from uterine fibroids may lose time from work, have higher medical bills, and might need advanced treatment in order to become pregnant.

The condition disproportionately affects African-American women, who are four times more likely to have fibroid tumors than women from other ethnic groups.

The researchers say they are now recruiting participants for human trials.

The Facts about Green Tea Fat Burners

Weight loss is a major concern for million of people around the world, but also staying healthy while reducing their overweightness. It is a well-known fact that a large number of products, medications and over-the-counter drugs can cause harsh side effects that you can avoid by taking a natural alternative.

One of the most renowned fat burners is made of Green Tea, an herb native to China, Japan and other Asian counties, also used as one of the ingredient in many diet supplements. There are many uses for Green Tea such as the fact that several people drink an infusion of leaves as a health tonic.

Green Tea Fat burners are prepared with dried leaves, which are not fermented to ensure minimal oxidation while this natural product is processed. Diet supplements also include Green Tea in their formulation, because it helps in weight loss, but also prevents free radical damage, that usually occurs from pollution and sun exposure.

Among the different fat burners from natural origin, only Green Tea is rich in polyphenols, vitamins C, E and 200 times more antioxidants than vitamins alone. Apart from aiding with weight loss, this tea soothes irritated skin and is an effective anti-inflammatory and anti-bacterial agent.

As a diet supplement, Green Tea is recommended as a high-energy source for weight loss. Recent studies have also found that a Green Tea leaf has more anti-carcinogens that any other tea. Many alternative medicine practitioners recommend trying both of two medicinal varieties: Kiln-roasted and steaming tea, which characteristically has a bitter taste.

Another benefit of Green Tea Fat Burners is the complementary protection to weight loss programs, since it was found that this herb prevents the absorption of fat from intestines, protecting the digestive system and preventing respiratory infections.

There are also many natural products for healthy skin, which main ingredient is Green Tea.

As an herbal extract, Green Tea Fat Burners of Chinese origin contains 50% of polyphenols, renowned antioxidants recommended to people who are following a weight loss diet.

Although the U.S. Food and Drug Administration (FDA) does not recognize the health benefits of Green Tea, researchers have found numerous health benefits in Green Tea burners and diet supplements. Such benefits include prevention in degradation of cell membranes, anti-sclerosis and anti-arthritis properties, effective lowering of cholesterol, and useful to stop neurodegenerative diseases, including Alzheimer’s.

Because this is an herbal treatment, it is safer that most chemical drugs and medications but make sure to visit your health care provider to help you determine the dosage that works for you in your weight loss treatment.