Tea is the most widely consumed beverage in the world, second only to water. Green tea in particular has gained great popularity in recent years, largely due to the tremendous amount of research showing its ability to support the body’s natural defenses against a large array of health issues, such as arthritis, cancer, cardiovascular disease, cognitive impairment, diabetes, and weight gain.
The History and Mythology of Green Tea
Archeologists have found that people in China and India ate tea leaves steeped in boiling water as far back as 5,000 years ago. Green tea has been used in traditional Chinese and Indian medicine for centuries as a stimulant, diuretic, and astringent (to control bleeding and help wounds heal), and to support heart health. Additional uses of green tea have historically included treating flatulence, regulating body temperature, regulating blood sugar, promoting digestion, and improving mental processes.
There is a popular legend in India concerning the origins of the tea plant. It is said that when Prince Siddhartha Gautama, the founder of Buddhism, was traveling through China, he became frustrated at his inability to stay awake during meditation so he tore off his eyelids. They say that a tea plant sprouted from the spot where his eyelids fell, and the plant gave him the ability to stay awake, meditate and reach enlightenment.
Currently about 500,000 tons of green tea is produced each year throughout Asia and in parts of the Middle East and Africa. It is mostly consumed by people in Asia, the United States, Europe and some parts of North Africa.
There are three main varieties of tea – green, black and Oolong – that come from the leaves of the Camellia sinensis plant. To make green tea, the newly harvested leaves are immediately steamed to prevent fermentation and preserve the natural polyphenols. This process also preserves the green color of the leaves. When the leaves are allowed to partially ferment, they turn into Oolong tea; and when they fully ferment, they become black tea.
What’s So Good About Green Tea?
Green tea contains high concentrations of polyphenols, called catechins, which have potent antioxidant properties. Antioxidants are essential to good health because they neutralize free radicals – harmful molecules that damage our cells and DNA, and increase vulnerability to numerous illnesses including heart disease and cancer.
Although there are six primary catechin compounds in green tea, epigallocatechin gallate (EGCG) is the most active and also the most studied. It is 100 times more effective in neutralizing free radicals than vitamin C and 25 times more powerful than vitamin E.
Green Tea and Weight Loss
Although there is no magic elixir that can cause you to lose a lot of weight without trying, there are a number of studies showing that green tea can give a significant boost to your weight loss efforts. Here are four ways green tea may support your weight loss goals:
1. Green Tea Increases Fat Oxidation
Based on recent data from human studies indicating that green tea extracts may support body weight reduction by increasing thermogenesis and fat oxidation, a 2007 German study looked specifically at the effect of EGCG on weight loss. They found that EGCG “has the potential to increase fat oxidation in men and may thereby contribute to the anti-obesity effects of green tea.”
2. Green Tea Increases the “Good” Fat While Shrinking the “Bad” Fat
Your body has two types of fat: white fat and brown fat. The white or “bad” fat is what you see growing on your body when you gain weight. The brown or “good” fat actually helps you burn more calories and shrinks the size of your white fat cells. A 2017 study published in the American Journal of Clinical Nutrition found that the catechins and caffeine in green tea increased the amount of brown fat in the participants. The more brown fat you have, the less white fat you’ll have, making green tea a win-win when it comes to weight control.
3. Green Tea Can Help Reduce Belly Fat
The EGCG catechin found in green tea can help block the formation of new white fat cells. A 2005 Japanese study found that men who drank green tea containing 136 milligrams of EGCG lost twice as much weight and four times as much abdominal fat compared to the placebo group.
4. Green Tea Can Help Regulate Blood Sugar
High blood sugar leads to weight gain because it signals your body to store more glucose as fat, increases unhealthy cravings, and lowers energy levels. In 2014, two studies — one Japanese study and one Mexican study — found that green tea’s antioxidants were able to limit the amount of carbohydrates absorbed by the body. The result of fewer carbs being absorbed is that sugar metabolism and blood glucose levels are improved, which in turn contributes to weight loss.
Green Tea and Cardiovascular Health
In a 2008 review of current scientific evidence relating to green tea’s ability to support a healthy cardiovascular system, scientists reported that the more green tea people consumed, the lower their risk for cardiovascular disease.
Subscribe to the World's Most Popular Newsletter (it's free!)
Here are the results from two other individual studies dealing with green tea and cardiovascular health:
- A 2009 study looked at the cardiovascular effects of short-term green tea consumption. Participants were asked to drink four cups of green tea per day for 14 days without altering any other part of their normal diet. At the end of the two weeks, the participants showed reductions in blood pressure, fasting total cholesterol, body fat and body weight. These results suggest that green tea may have a positive role in reducing cardiovascular risk factors.
- A 2001 study conducted in Japan found that the tea catechin EGCG inhibited the oxidation of LDL cholesterol in vitro. Since the oxidation of cholesterol is what causes it to become “sticky” and form plaque in the arterial walls, inhibiting its oxidation is an important factor in helping to prevent cardiovascular problems.
Additional Green Tea Health Benefits
Although the majority of green tea research seems to have focused on cancer and cardiovascular disease, there are also hundreds of other studies evaluating the benefits of consuming green tea for just about any health issue you can imagine – from asthma to genital warts, and from dental cavities to the common cold.
Following are samples of other areas of green tea research:
Diabetes Risk – In an interesting 2004 study, researchers looked at glucose metabolism in both diabetic mice and healthy humans. They found that green tea promoted glucose metabolism in healthy humans and lowered blood glucose in diabetic mice. They concluded that the study “provides evidence that green tea has an antidiabetic effect.”
Rheumatoid Arthritis – In a 2008 study, investigators at the University of Maryland and Rutgers University examining the effects of green tea polyphenols on rheumatoid arthritis found that green tea significantly reduced the severity of symptoms. They suggest that green tea affects arthritis by promoting positive changes in various arthritis-related immune responses.
Cognitive Functioning – A 2006 study of 1,003 volunteers examined the association between green tea consumption and cognitive function in humans. Researchers concluded that a higher consumption of green tea is associated with a lower prevalence of cognitive impairment in humans.
To Drink or To Supplement…
Is it better to drink your green tea or to take a green tea extract supplement? While drinking green tea is certainly good for you, there are a couple of reasons why supplementing with EGCG-rich green tea extract is better:
- Convenience. It would be difficult to drink the quantity of green tea needed each day to provide the recommended amounts of EGCG – often 10 cups a day or more. Or you could take a single veggie cap of ProHealth’s Green Tea EGCG Extreme – the most potent green tea extract on the market today.
- 99.6% caffeine free. Even if you could drink the needed 10 cups a day or more of green tea, you would be getting a great deal of caffeine with it. The Green Tea EGCG Extreme supplement contains only a tiny amount of caffeine.
Green tea – studied extensively in humans, animals and laboratory tests – contains powerful antioxidants and has been shown to promote good health. Research continues as more and more specific health benefits are discovered each year.
This article, originally published on June 1, 2010, was updated on February 24, 2021.
Note: This information has not been evaluated by the FDA. It is general and is not intended to prevent, diagnose, treat or cure any illness, condition, or disease. It is very important that you make no change in your healthcare plan or health support regimen without researching and discussing it in collaboration with your professional healthcare team.