Green tea is probably more well known for its health benefits than any other food or drink. The National Institutes of Health PubMed database now has thousands of reports on green tea health benefits.
Green tea has been used for its health-building properties for at least 4,000 years. It contains as wide a variety of antioxidants as any food or beverage.
The primary source of green tea health benefits are powerful antioxidants called flavonoids and polyphenols. The amount of flavonoids and polyphenols in a cup of freshly brewed tea vary depending on the variety and how it was processed and brewed.
There are five flavonoids in green tea called catechins that are especially beneficial; of these, scientists now agree that the catechin named epigallocatechin gallate (EGCG) has the highest level and broadest spectrum of antioxidant properties and benefits.
For comparison, green tea contains approximately 15 to 30 percent catechin content; oolong tea, 8 to 20 percent; and black tea, 3 to 10 percent.
See the page on Green Tea Facts to learn more about the differences between green, white, oolong and black teas.
These unique catechins act as highly potent antioxidants that protect your arteries and heart, regulate blood-sugar, reduce high cholesterol and blood pressure and fight against viruses and bacteria. Green tea has a stimulating effect on the immune system because its polyphenols boost production of immune system cells.
Catechins are similar to the proanthocyanadins found in grape seed extract, pycnogenol, bilberry and ginkgo biloba. Of these, green tea was found to be the best at scavenging deadly free radicals. In some ways, it is a far more effective in antioxidant activity than vitamin E or vitamin C.
Green Tea and Heart Disease Prevention.
Studies have shown the relationship between green tea and a low incidence of heart disease, similar to what is seen in the "French Paradox." For years, researchers were puzzled by the fact that, despite eating a high-fat diet and smoking cigarettes, the French have a lower incidence of heart disease than other western countries.
The answer was suspected to be their high consumption of red wine, which contains an antioxidant called resveratrol. Researchers have determined that the EGCG in green tea is twice as powerful as resveratrol, which may explain why the rate of heart disease among Japanese men is also quite low, even though the majority of them are smokers.
Green tea contains high levels of another powerful antioxidant, quercetin. Together with the catechins, these flavonoids not only reduce oxidation of LDL cholesterol, but have powerful anti-cancer effects as well.
Take Milk with Your Tea? Adding milk to tea will block the healthy effects that tea has in preventing cardiovascular disease. This occurs because casein from the milk binds to the EGCG in tea that cause the arteries to relax. Milk may also block green tea's benefits in other areas, such as cancer prevention.
Honey, on the other hand, makes a great addition to your cup of tea. There are countless benefits of honey.
Green Tea Promotes Fat Loss. Green tea health benefits include its ability to promote weight loss in several ways: it helps your muscles accelerate fat breakdown, and it can help reduce your appetite.
Research suggests that if the average person were to drink five cups of green tea a day, they would burn an extra 70 to 80 extra calories per day as a result of green tea's ability to boost your metabolism.
Now, 70-80 calories a day doesn't add up to much weight loss on its own. To lose one pound of fat a week, you need to burn off 500 extra calories per day. So if you were to rely only on green tea, it would take about 50 days to lose 1 pound, drinking 5 cups a day. Over the period of one year, you could expect to lose about 7 pounds.
Green tea can still be quite useful as part of a complete weight loss program for the slight metabolism boost it gives you. Also, drinking a cup of green tea 20 minutes before a meal does help reduce your appetite. You'll often find weight-loss products containing green tea extracts for these reasons.
Green Tea Offers Protection Against Alzheimer's and Parkinson's Disease. The catechins in green tea are known to provide a wide spectrum of protection to the brain. These include free radical scavenging and regulation of cell activity and mitochondrial function in the brain cells. The end result is a significant lessening of damage to brain cells from free radicals.
Green Tea Health Benefits Include Cancer Prevention. Much of the current research on green tea has focused on its cancer-fighting ability. As with other antioxidants, there is evidence that shows that green tea prevents damage to DNA that initiates the cancer process. The powerful antioxidants in green tea not only inhibit the growth of cancer cells, they kill cancer cells without harming healthy tissue.
Green tea has been associated with prevention of several different types of cancer, including lung, breast, pancreas and stomach cancer. That has now been expanded to include all of the digestive system cancers like those of the esophagus and colon. Digestive cancers now account for one-third of all cancer deaths in the USA.
Other Green Tea Health Benefits. Some of the well-documented health benefits of green tea include the treatment and prevention of the following health problems:
Japanese doctors have found that drinking a cup of tea after meals helps prevent cavities and gum disease because the polyphenols kill the bacteria that causes dental problems.
Population studies suggest that green tea consumption may help prevent type 2 diabetes. New studies suggest that green tea may improve glucose tolerance and insulin sensitivity in individuals with diabetes.
Green tea may increase your stamina: green tea extract given to lab rats increased the amount of time the animals could swim before becoming exhausted by as much as 24%.
Green tea strengthens bones much like calcium or exercise does. Researchers have shown drinking green tea may significantly increase bone mineral density.
Green tea contains caffeine, about half of that found in coffee. The amount of caffeine that ends up in your cup of green tea will vary according to the amount of tea used and the length of time the leaves are brewed. Most of the caffeine in green tea is extracted into the water the first time the tea is infused. If the same leaves are then used for a second brew, the caffeine level drop off to about one-third of the first cup, and decreases more with each subsequent cup brewed.
If you use decaffeinated green tea, you'll want to know that decaf green tea has about half the antioxidant content of regular green tea. This means that you would have to drink twice as much tea to get the same amount of green tea health benefits.
Green tea is known to have high levels of fluoride and aluminum, two highly toxic substances. Decaffeinated green tea has even higher levels of than regular green tea. So before you decide on a green tea regimen, you'll want to learn more about the potential health hazards, and how to minimize them, at my page on green tea side effects.
The most health benefits can be derived from using green tea in its least-processed state — tea leaves. Tea bags don't quite provide the same benefit as the entire green tea leaf, although a superior quality, organic source will do just fine. It's also important to obtain your tea from a source that guarantees the tea's freshness.
Much of the research supporting the health benefits of green tea is based on the amount of green tea typically consumed in oriental countries, approximately 3 cups per day.
However, other research suggests as much as 10 cups per day is necessary to obtain any noticeable health benefits. In any event, most green tea health benefits will typically not be seen overnight. It may take some time, but in the meantime, as long as you enjoy it as a beverage, don't worry about getting the benefits.
Tablets and capsules containing standardized extracts of green tea might be a better option if you're looking for the easiest way to get the advantages of green tea. Some provide up to 98% polyphenol content — which would be the equivalent to drinking about 4 cups of tea. Many of these standardized products are decaffeinated, too.
See my page on Green Tea Supplements
Other pages on this website about green tea:
Protect the Future of Your Food Supply