- destroy bacteria and help prevent viral infections
- balance intestinal bacteria
- protect against hardening of the arteries
- reduce low density lipoprotein (LDL [bad]) cholesterol
- prevent diabetes
- promote weight loss
- balance blood sugar
- protect against high blood pressure
- strengthen blood vessel walls
- slow the aging process
- reduce cancer risk
- prevent bad breath and cavities
- decrease the risk of Parkinson’s and Alzheimer’s diseases
- boost the immune system
- reduce allergy symptoms
- promote healthy skin tone
- stimulate the brain and nervous system
- promote relaxation
- stimulate tissue growth
What the Experts Say
“Recent research on the health benefits of tea is impressive. Tea contains a group of polyphenols (catechins) that are lessened by the oxidation process used to make ordinary black tea. The principal one, called EGCG, is one of the most powerful antioxidants known. It has significant anticancer effects, lowers serum cholesterol, and does many other good things for the body. Green tea has more of it than black tea (Chinese white tea has even more but is harder to find). If you want to use a caffeinated beverage, green tea looks like the wisest choice.”
Natural Health, Natural Medicine by Andrew Weil, M.D.
“It is critical that coffee is completely eliminated from our diet. Coffee raises levels of cortisol and insulin, hormones that accelerate aging and store body fat. Substitute green tea instead, which contains catechin polyphenols, antioxidants that boost metabolism and slow aging. Green tea can also block the absorption of bad fats by 30 percent, while the amino acid theonine promotes a sense of calm and improves one’s mood.”
The Perricone Perscription by Nicholas Perricone, M.D.
“Get 31 milligrams of flavonoids a day. Flavonoids are powerful antioxidants and anti-infammatory substances that occur in certain plant foods, including nuts; any tea, including green tea; red wine; grapes; cranberries; 100 percent natural orange juice; onions; and tomatoes and tomato juice. You can take in this amount by drinking two and half glasses of cranberry juice or several cups or glasses of tea.”
YOU: The Owner’s Manual by Michael F. Roizen, M.D. and Mehmet C. Oz, M.D.
“If you lived in China, you would probably be drinking green tea and taking green tea extract. We know it has anticancer properties. It is an immune system stimulator. Decaffeinated green tea is very beneficial.”
Get Healthy Now! with Gary Null: A Complete Guide to A Complete Guide to Prevention, Treatment, and Healthy Living by Gary Null, Ph.D.
“Some of the most exiting research involves the link between green tea and the prevention of cancer. Additionally, green tea eases the adverse effects of cancer therapies, such as radiation and chemotherapy. Other research shows that tea, and green tea in particular, bolsters the heart’s resistance to cardiovascular diseases, prevents dental cavities, lengthens a tea drinker’s life span, detoxifies the body, aids in weight loss, decreases cholesterol levels, protects skin from sun damage, relieves mental distress, and boosts the immune function. And over the years, the research in these areas has gotten more positive.”
The Green Tea Book – The Science-Backed “Miracle Cure” – by Lester A. Mitscher, Ph. D. and Victoria Dolby Toews, MP
According to Mitscher and Toews (2008), three to six cups of green tea per day can improve your health. They say:
- Drinking any amount of tea regularly makes it 40% more likely that a person who has a heart attack will survive and still be alive three years later.
- One to two cups daily lowers the risk of severe hardening of the arteries (atherosclerosis) by 46%.
- Two cups a day leads to a 50% reduction in heart disease in general.
- Three cups a day slashes the risk of having a heart attack by 43%.
- Three cups a day lowers LDL (bad) cholesterol levels.
- Four cups a day greatly lowers the risk of skin cancer.
- Five cups a day lowers stroke risk by 62% in women and 42% in men.
- Five cups a day reduces the chances of developing breast cancer.
The nutrients in green tea are tannin (catechins), caffeine, theanine, and vitamin C, which are not in coffee and are in lesser amounts in other teas. Black tea has no vitamin C.
| Tea Type | Tannin(%) | (Catechins)(%) | Caffeine(%) | Theanine(Amino acids)(%) | Vitamin C(ml) |
| High grade Japanese green tea(Gyokuro) | 12 | 10.0 | 3.5 | 4.0 | 150 |
| Japanese green tea(Sencha) | 15.6 | 13.8 | 2.3 | 2.3 | 300 |
| White tea | 15.0 | 11.1 | 2.6 | 1.5 | 144 |
| Oolong tea | 16.1 | 3.4 | 3.7 | 1.0 | 44 |
| Black tea | 21.3 | 5.7 | 3.7 | 1.0 | 0 |
Polyphenols
Phytonutrients or nutriceuticals are naturally occurring compounds in plants that protect against disease and promote good health. Many act as hormones, enzymes, pigments, or growth regulators, and many are transferred when we consume plants. One class, polyphenols, is present in tea as well as in apples, onions red wine and other foods. Polyphenols are best known as antioxidants and represent approximately 30% of the green tea leaf after processing.
Catechins (Tannin)
The four primary polyphenols in green tea are: epicatechin (EC); eipcatechin gallate (ECG); epigallocatechin (EGC); and epigallocatechin gallate (EGCG) – collectively known as catechins. One study found that EGCG had an antioxidant effect 200 times that of vitamin E. Sencha, has the most catechins.
Caffeine
Black tea has the greatest amount of caffeine, oolong has half as much, and green and white teas have about one–third as much. Teas also have methylxanthines, which are stimulants.
One serving of coffee has 60-160 mg of caffeine, while a serving of green tea has 6‑30 mg. Caffeine has been found to increase cognitive performance, alertness, and energy. It can also help with weight loss through its stimulating and mild diuretic effects.
Drinking green tea does not have a dehydrating effect. Although it does act as a mild diuretic, green tea provides a net gain of fluid.
The green teas with the highest caffeine content are matcha, gyokuro and sencha. Houjicha (bancha) and genmaicha have the lowest caffeine content.
Theanine (L-Theanine)
Green tea contains several amino acids, including teanin or L-theanine. Tea is the only plant that makes L-theanine, which has attracted the attention of cancer researchers since it enhances the effectiveness of some anti-cancer medications while minimizing their side effects. L-theanine also adds sweetness to the taste, counteracts some of the stimulant effects of caffeine, and has a relaxing effect on the mind.
Controlled experiments have shown that L-theanine has a positive effect on the mind and improves memory by increasing dopamine levels. The experiments also show that alpha brain waves increase 40 minutes after consuming L-theanine.
Gyokuro and matcha are especially rich in L-theanine because the tea leaves are grown in diffuse sunlight before harvest.
Vitamin C and E
The effects of vitamins C and E include an anti-oxidization action and slowing if the aging process.
Vitamin C, catechin, and vitamin E in green tea work together to enhance immune function. These three nutrients also help to make the skin more beautiful by reducing blemishes, wrinkles and sun damage. Vitamin C found in green tea is water-soluble and heat-resistant, so its potency is not reduced. Sencha contains the highest amount of Vitamin C.
Bioflavonoids
The bioflavonoids found in green tea help to keep teeth and gums healthy. Gargling with green tea after brushing teeth kills germs and prevents bad breath.
Minerals
Green tea is rich in minerals, including manganese, potassium and calcium, which help to alkalinize the blood, regulate the heartbeat, and build strong teeth and bones.