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Does Green Tea Truly Make People Lose Weight?
By: Fatmata Daramy
September 24, 2007
Today in the United States, one hundred and twenty seven (127) million adults are considered overweight, sixty (60) million are obese and nine (9) million are severely obese. Over the last thirty (30) years, there has been a huge increase in the percentage of overweight and obese adults. Obesity has become an epidemic in the United States and the World Health Organization has labeled it as a ‘global epidemic’ (Volpe, 2006). The steep rise in obesity can be seen in the number of children who are considered overweight, obese, and morbidly obese, and the number of chronic disease that is associated with obesity. In fact now obese and morbidly obese children are being diagnosed with type two diabetes mellitus, a disease that was previously only seen in adults (Volpe, 2006).
In the midst of this current obesity epidemic, many people are trying to lose weight loss. Americans have tried to transferred their fast pace of life to weight loss, wherein they want to lose as much weight as possible in the shortest span of time. Many have turned to various weight loss fads and the weight loss industry has boomed due to the obesity epidemic (Volpe, 2006). People are willing to spend money on diet pills, remedies, books and videos in the hope to of losing weight.
Amongst these weight loss fads, weight loss medication and supplements have become very popular. Many American have relatively greater expectations about the weight they will lose with diet, supplements, or weight loss medication. There are many advertisements for weight loss options that promise extreme weight loss coupled with personal testimonials. However these have failed many people and even when they have worked, individuals have regained there original weight and sometimes even more. Even though many people are Americans are going through their current weight loss phase, the number of overweight and obese individuals continues to surge as recidivism is high in weight management (Volpe, 2006).
A very popular ingredient in many weight loss medications is green tea extract which is actually supposed to help one lose weight. But does green tea extract actually help an individual lose weight or is it just another useless weight loss supplement that people are wasting money on. Is green tea a fabulous and true way to lose weight or is it just faux?
The consumption of green tea leaves, based on archeological data, can be dated as far back as 500,000 years ago. Based on botanical evidence, India and China were one of the first countries to consume tea but today, tea is drank all over the world. There are three types of teas- green, black and oolong which are all derived from the leaves of the Camellia Sinensis plant which grows in Asia, the Middle East and Africa. Green and oolong tea are more commonly used in Asia whilst black tea is more popular in the United States. Green tea has also been used in traditional Chinese and Indian medicine as a stimulant, diuretic, astringent, for health problems, flatulence, regulating body temperature and blod sugar, digestion and mental processes.
Green tea is claimed to have possible health benefits. The healthful properties of green tea are largely attributed to their unfermented leaves and high concentration of polyphenols, chemicals with powerful antioxidant properties, which also gives it is slight bitter taste. Polyphenols’ antioxidant effects are said to be greater than that of vitamin Cs. Antioxidants work to neutralize free radicals, which are damaging compunds that are natural produced in the body or by environmental toxins, and prevents their damaging actions. Polyphenols found in teas are classified as catechins. Green tea has six primary catechin compounds: catechin, gallaogatechin, epicatechin, epigallocatechin, epicatechin gallate, and apigallocatechin gallate (also known as EGCG). Amongst the six primary catechin compounds, apigallocatechin gallate (EGCG) is the most active and most studied polyphenol component in green tea. Green tea also contains alkaloids such as caffeine, theobromine, and theophylline, which gives green tea its stimulant effects. (http://www.umm.edu/altmed/articles/green-tea-000255.htm)
Purpose of this treatment or intervention
There has been extensive studies performed in people, animals and laboratory experiments and results from these studies have suggested that green tea may have important uses and has some health conditions. Many of these studies have suggested that green tea extract boosts metabolism and may help with fat burn. A study confirmed that the use of green tea and caffeine improved weight loss and maintenance in overweight and moderately obese individuals. Another study found that weight maintenance following weight loss was not affected by green tea. (http://www.umm.edu/altmed/articles/green-tea-000255.htm)
Mechanism of Action
Green tea is said to have many medicinal properties. Traditionalist Indian and Chinese medicine healers have used green tea cure many ailments. Now many scientific studies are confirming that green does have some beneficial health properties such as green tea “can boost the immune system, inhibit the cancer process at virtually every stage, regulate cholesterol levels, assist in weight loss, fight free radical damage, and ward off viruses, fungi and food-borne bacteria. It also inhibits dental plaque formation, lowers the risk of type 2 diabetes, slow cognitive decline, and may even help increase the lifespan”. The source of theses medicinal properties found in green tea is the high concentrations of catechin polyphenols present in green tea. (http://www.greentea.com/Nadine%20Taylor.asp)
Green tea contains high quantities of several polyphenolic components. The polyphenolic components found in tea are classified as a particular subclass of flavonoids commonly known as tea catechins. These six primary polyphenolic components are epicatechin, epicatechin gallate, epigallocatechin. Epigallocatechin Gallate (EGCG) is the most abundant and the most pharmacologically active. The primary mechanism of action of green tea is the catechins in green tea stimulate thermogenesis and fat oxidation by inhibition of catechol O-methyl-transferase (COMT). Catechol O-methyl-transferase (COMT) is an enzyme that degrades norepinephrine (NE), a stress hormone that releases stored energy from fat. Green tea extract has been shown to increase sympathetic nervous system (SNS) activity acutely (Bérubé-Parent, 2006). There has also been a noticeable increase of the metabolic rate and fat oxidation in humans in the short-term. Green tea extract also contains caffeine. Caffeine has been shown to stimulate thermogenesis. Green tea extract also stimulates thermogenesis. However, it cannot solely be cannot be attributed to its caffeine content because the thermogenic effect of green tea is greater than an equivalent amount of caffeine. Studies have shown that green tea has thermogenic properties beyond that of caffeine’s content. Therefore, green tea, containing tea catechins and caffeine, acts at various steps of modulatory pathways, that is, via phosphodiesterase, and via catechol O-methyl-transferase (COMT), and in this way exerts a thermogenic and possibly an anti obesity effect (Diepvens, 2007).
Claims about Green Tea and Weight Loss
Based on green tea’s possible anti-obesity effect, many weight loss products especially weight loss pills contain green tea or green tea extract. These products have many claims about the use of green tea in their products and its ability to burn tremendous fat.
On a website, it states that one can lose thirty (30) pounds in three weeks without any diet, amazing weight loss secret as seen on CNN and 60 Minutes. Burn 30lbs in 30 Days Guaranteed with Thermocerin: The world’s Most Powerful Fat Burner. Even though it is impossible and even unsafe for an individual to lose a pound a day, the site includes testimonials to back up its claims and to make a potential client believe in its absurd claims. (http://www.thermocerin.com/google/index.html?gclid=CKLWo5yb2o4CFREDWAodM1foAw)
Another web site says, Green tea for wieght loss and fat burning? Avatrim: Green Tea Blend Diet Pill is advertised on http://avatrim.productsherbal.com/. It claims that “Numerous laboratory researches and real-life tests has proven Avatrim to be one of the most effective weight loss formulas today. It's 100% ephedrine-free - active ingredients of Avatrim include: green tea extract and several other herbal extracts known to increase the metabolic rate in the human body, which results in significant body fat reduction and weight loss. Better metabolic activity also results in healthier and much more active lifestyle” (http://avatrim.productsherbal.com/). This sound more plausible than the previous claim by Thermocerin. However it is not 100% truthful. Green is said to possibly have an anti-obesity effect. Avatrim states significant body fat reduction and weight loss due to green tea extract and other herbal extract. There is a lot of current research on great tea and weight loss, but this claim is an exaggeration of possible truth and is inconclusive.
It is important to note that all these weight loss claims that are made about pills with green tree extract do not have any substantial support. On most web sites, there are plenty of testimonials showings pictures of people who have benefited from the pill. However, these testimonials are not a hundred percent reliable. The companies producing these weight loss products are solely concerned with making substantial profit from sales of their product. They will say anything as a marketing device to sell their product. The testimonials are really not to educate a potential client but instead they are created as a marketing device to sell their products. Apart from testimonials, there is no other scientifically proven evidence that supports many of the outlandish claims that are made about weight loss products containing green tea. There is a lack of evidence and so the information on these websites should not be trusted. Instead, individuals need to investigate for themselves the truth about many of the weight loss products so that they can protect themselves.
The Truth about Green Tea
Scholarly articles are a great source to obtain true facts about weight loss products. Below are reviews of scientific studies that aim to reveal whether or not green tea alone can cause substantial weight loss.
In a short-term human study with ten healthy men, researchers investigated green tea extract and its ability to increase energy expenditure and the rate of fat metabolism. There were three possible treatments: a green tea extract tablet (epigallocatechin gallate plus caffeine 90/50 mg), caffeine (50 mg) or placebo capsules. The men were randomly assigned on of these treatments and they were administered three times daily on three different occasions-after meals. The treatment consisting of the green tea extract shows a substantial increase. However, compared to the placebo, the observed effect in 24 h energy expenditure is only that of 4% as it was only significantly higher than that with both the placebo and caffeine, by 3.5% and 2.8%, respectively (Dulloo, 1999). Therefore the difference is deemed insignificant.
In the Netherlands, a study was conducted to investigate whether green tea may improve weight maintenance by preventing or limiting weight regain after weight loss in one hundred and four (104) overweight and moderately obese subjects. The study consisted of a very-low-energy diet of 4 weeks followed by a weight maintenance period of 13 weeks in which subjects received placebo or green tea (Kovacs, 2004). The study’s results show that body weight regain and the rate of regain were not significantly different between the green tea and placebo group.
A study was recreated with the purpose to assess the effect of green tea extract in combination with low-energy diet on resting energy expenditure. This study consists of forty six (46) overweight women following a low-energy-diet combined with green tea or placebo supplementation during 12 weeks. Results from this study show that “the resting energy expenditure as a function of fat free mass and fat mass did not decrease significantly over time when green tea was ingested but the decrease in resting energy expenditure was significant in the placebo group” (Diepvens, 2005). However, there is not a significant difference in body weight loss between the green tea and placebo group. The use of green tea in combination with a low-energy diet showed no additional benefit.
Green Tea: Fab or Faux?
Our current state of a worldwide epidemic of obesity has threatened the health of populations. Obesity in combination with our current culture of beautiful being equivalent to skinny (many celebrities like Angelina Jolie are very thin) has instilled in people the craving to lose weight. People are in such dying want to lose weight so quickly that they are turning to weight loss methods that make false claims of radical weight in a very short amount of time. A very common ingredient in many weight loss pills is green tea extract, which is said to help people lose weight. However, scientific studies have proven that green tea does not help people to lose tremendous weight without diet or exercise.
Obesity is the result long term energy balance wherein an individual has had excess energy intake and very little energy expenditure. In order for an individual to lose weight, there needs to be shift to a negative energy balance. This can be achieved by decreasing energy intake and or increasing expenditure. A negative energy balance is needed to produce weight loss and can be achieved by either decreasing intake (eating less food) or increasing expenditure (exercise). No diet supplement or weight loss pill can help an individual lose weight without cutting down on food intake, eating healthy and or exercise. Green tea is a very healthier choice than many other beverages because it is natural and has no calories but only diet and exercise can help an individual to lose weight. Green tea is a fabulously healthy drink but it is completely faux in causing tremendous weight loss.
Bérubé-Parent, S., Diepvens, K., Joosen, A., Tremblay, A., & Westerterp-Plantenga, M. (2006). Metabolic Effects of Spices, Teas, and Caffeine. Physiology & Behavior, 89(1), 85-91.
Diepvens, K., Westerterp, K., & Westerterp-Plantenga, M. (2007). Obesity and thermogeness related to the consumption of caffeine, ephedrine, capsaicin, and green tea. American Journal of Physiology- Regulatory, Imperative and Comparative, 292, R77-R85.
Diepvens, K., Kovacs, E., Nijs, I., Vogels, N., & Westerterp-Plantenga, M. (2005). Effect of green tea on resting energy expenditure and substrate oxidation during weight loss in overweight females. British Journal of Nutrition, 94: 1026-1034.
Dulloo, A., Duret, C., Rohrer, D., Girardier, L., Mensi, N., Fathi, M., Chantre, P., & Vandermander, J. (1999). Efficacy of a green tea extract rich in catechin polyphenols and caffeine in increasing 24-h energy expenditure and fat oxidation in humans. American Journal of Clinical Nutrition, 70(6), 1040-1045.
Kovacs, E., Lejeune, M., Nijs, I & Westerterp-Plantenga, M. (2004). Effects of green tea on weight maintenance after body-weight loss. British Journal of Nutrition, 91: 431-437.
Volpe, S. L. (2006). Popular
Weight Reduction Diets. Journal of Cardiovascular Nursing, 21(1), 34-39.
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