The Eastern part of the world has long known the health benefits of
green tea, but the Western world has a lot of catching up to do! What is it about green tea that makes it one of the healthiest drinks in the world?
Both green and black tea are derived from the same plant, Camellia sinensis, a 3-foot/1-metre shrub that produces leaves that are 1 to 5 cm. long.
Four times as much black tea is produced and consumed as green tea each year, but green tea is healthier for you because it contains more of the compounds called poliphenols that have high levels of therapeutic activity and can protect against cell damage.
The difference between green and black teas results from the manufacturing process.
To produce black tea, the leaves are allowed to undergo natural fermentation which causes oxidation.
During oxidation, enzymes present in the tea convert polyphenols into substances with much less biological activity.
In contrast, green tea is produced by lightly steaming the fresh-cut leaves and then they are rolled and dried.
Steaming kills the enzymes that would otherwise ferment the leaves and convert polyphenols, so oxidation doesn't take place and the polyphenols remain intact.
Oolong tea is partially fermented.
White tea is still green tea, but the new, unopened buds are picked and steamed or dried. The resulting tea is pale yellow and low in caffeine and tastes mild and slightly sweeter than green tea.
Green tea provides significantly more health benefits than black tea due to its higher content of polyphenols, especially flavanols.
These polyphenols are phytochemicals with antioxidant, antibacterial, antiviral and health-enhancing properties and represent approximately 30% dry weight of the fresh leaf.
Catechins are the predominant flavanols and are mainly comprised of epigallocatechin gallate (EGCG), epigallocatechin (EGC), epicatechin gallate (ECG), and epicatechin (EC), the most active of which is epigallocatechin gallate (EGCG).
Tests on this particular type of polyphenol have shown that it's able to penetrate the body's cells and shield DNA from hydrogen peroxide, a potent free radical.
In addition to serving as antioxidants, green tea polyphenols may increase the activity of antioxidant enzymes in the small intestine, liver and lungs.
Green tea has been proven effective for the following conditions:
A number of experiments conducted in test-tube and animal cancer models have shown that green tea polyphenols inhibit cancer by blocking the formation of cancer-causing compounds, such as nitrosamines, suppressing the activation of carcinogens and detoxifying or trapping cancer-causing agents.
One US study found that EGCG prompts cancer cells to stop reproducing by stimulating a natural process of programmed cell death called apoptosis. Remarkably, EGCG doesn't cause damage to healthy cells.
According to researchers at the University of Kansas, green tea's main antioxidant EGCG is 100 times more powerful than vitamin C and 25 times more potent then vitamin E in protecting DNA from the kind of damage thought to increase the risk of cancer.
The forms of cancer that appear to be best prevented by green tea are cancers of the gastrointestinal tract, including cancers of the stomach, small intestine, pancreas and colon; oestrogen-relate cancers, including most breast cancers; and prostate cancer.
Although important in fighting all of these cancers, the health benefits of green tea are particularly evident in preventing breast and prostate cancer.
The catechins present in tea are responsible for delaying atherosclerosis, strengthening capillaries, thinning the blood and lowering blood pressure according to numerous studies carried out by Russian scientists.
Japanese scientists have isolated a substance from green and black tea that lowers blood pressure in rabbits. But they admit that it's difficult to isolate a single ingredient responsible for all the benefits of green tea.
In test-tube studies these compounds appeared to suppress the damage to LDL cholesterol, thought to be an initial step in the build-up of plaque in the arteries.
A recent study found that women who drank at least five cups of green tea every day were half as likely to suffer a stroke as those who drank tea less. It was also true of women with high salt intake, who typically have increased risk of high blood pressure and stroke.
One explanation given was the high concentration of antioxidants in tea, which might protect blood vessels from damage.
One study found green tea chemicals even stronger in antioxidant effect than vitamin E and C, well known for their potent antioxidant powers.Read more on Green Tea and Strokes
The health benefits of green tea extend also to your teeth.
The strong concentration of antioxidants in green tea, and specifically the catechins, appear to have a good effect on reducing cavities, plaque build-up, and periodontitis – in other words, dental and oral health.
The reason is twofold:
Green tea and vitamin K
Green tea leaves contain hefty amounts of vitamin K, but a cup of brewed tea or green tea supplements have virtually none.
People taking anticoagulant drugs for heart disease - who have to avoid large servings of foods rich in vitamin K because of the vitamin's influence on blood clotting - can therefore enjoy green tea with no fear of side effects.
Drinking hot tea
Drinking boiling-hot green tea can damage your throat and oesophagus and may over time increase your risk of cancer.
Try the traditional Asian Method: heat cold water until just before it boils (or boil it and let it cool for a few minutes), then pour the hot-but-not-boiling water over the tea leaves. This methods accents the delicate flavour of green tea.
Gunpowder tea, imported from China, is simply green tea presented in tiny pellets resembling gunpowder. When placed in hot water the leaves slowly unfold.
Best way to make the tea
If you're now convinced to take up tea drinking, the best way to get the best out of it is to dunk the teabag in the water several times. When researchers compared dunking teabags to soaking them they found dunking for 3 minutes releases up to five times more polyphenols than simply letting the bag sit in the hot water.
Green tea and milk
Green tea doesn't lend itself to be drunk with milk. You may find the taste of green tea unusual at first, but if you try it a few times, you'll soon get used to its robust taste. It took me a while to appreciate its flavour, but I find it really refreshing now. I particularly like it with lemon and if you follow the directions above on how to brew it, it won't be bitter at all.
Green tea contains caffeine, so in some sensitive individuals it may cause nervousness, anxiety, insomnia and irritability.
Fortunately, decaffeinated green teas and decaffeinated green tea extracts are now widely available.
Caffeine Content of Tea and Other Caffeinated Beverages:
Enjoy the benefits of green tea's anti-oxidant compounds with this high concentrated standardized extract.