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Cancer, Heart Disease and Bad Breath

Studies of Green tea's value in maintaining good health have been conducted and reported in medical journals around the world.

Green Tea and Cancer

Of particular interest are the studies that indicate that Green tea helps reduce the risk of cancer. Experts believe that its powerful antioxidants help to disarm free radicals (highly relative oxygen compounds that damage healthy cells), which are believed to contribute to many degenerative diseases, including heart disease and cancer. The American Journal of Epidemiology has reported that a study of 35,369 women and their incidence of cancer during an eight-year period linked regular Green tea drinking with a lower risk of cancers of the upper digestive tract, colon and rectum. In Britain, positive results have been attributed to using Green tea to combat tumours of the colon, pancreas and breast. It is interesting to note that the amounts of Green tea used were not megadoses; only about four (4) cups per day!

Published studies in Australia by the CSIRO (here and here) have confirmed what Chinese and Japanese scientists, doctors and consumers of Green tea have known for years - Green tea is good for you! While all tea is healthy to drink, Green tea (derived from camellia sinensis) contains the highest level of polyphenols (flavonoids), which are known for their antioxidant activity.


Polyphenols or flavonoids are antioxidants and these compounds are most prevalent in Green teas particularly EGCG (epigallocatechin gallate - the most powerful. EGCG has the ability to block the enzyme urokinase, which helps tumours grow by attacking neighbouring cells. EGCG effectively destroys urokinase s ability to destroy good cells. Polyphenols' antioxidant ability helps cell DNA to reproduce itself accurately rather than in a mutated form, and Chinese medicines from green polyphenols have long been used to treat nephritis (kidney disease), hepatitis( liver disease) and even leukaemia. Polyphenols scavenge cell damaging free radicals, which are linked with cancer-causing genes and cause LDL cholesterol to form artery-clogging plaque. The polyphenols in tea possess 20 to 30 times the antioxidant potency of vitamins C and E. Antioxidants impair the ability of free radical cells to harm the molecules that make up our bodies.

Antioxidants are known to be beneficial in fighting certain cancers and reducing the effects of ageing. It has been proposed that the high consumption of Green tea in Japan may be one of the positive contributing factors for low levels of cancer of the prostate in men and lower levels of breast cancer in women (along with higher consumption of isoflavones eg tofu, miso & soy bean products).

These new studies point to evidence that these healing properties have a scientific basis. Consumption of tea is being studied for its reported benefits on: Enhancing immune function
Lowering LDL cholesterol levels (CSIRO research)
Increasing HDL cholesterol levels
Reducing blood pressure
Thinning the blood
Reducing the risk of a heart attack
Lowering the risk of stroke
Reducing the risk of cancer
Boosting longevity
Weight loss - research paper
Aiding digestion
Preventing dental cavities and gingivitis

According to the Chinese herbal classic, the Pentsao, common black or Green tea has several health benefits. Properties and Uses: Brightens the eyes, clears the voice, invigorates the constitution, removes flatulence, opens the acupuncture meridians, illumines the spirit, improves the digestion, relieves thirst and is cooling, diuretic and astringent. As a digestive aid, tea also has a special solvent property that cuts the fats and oils from a rich meal.

Green Tea and Heart Disease

British researchers have discovered that four to five cups of Green tea a day might help reduce both high cholesterol and high blood pressure. Green tea seems to work not only in reducing LDL-cholesterol oxidation but also in lowering overall blood cholesterol levels.


Tea is a dietary source of important vitamins and minerals. Tea contains Carotene, a precursor to vitamin A; Thiamine (vitamin B1); Riboflavin (vitamin B2); Nicotinic acid, Pantothenic acid, Ascorbic acid (vitamin C) vitamin B6; Folic acid; Manganese, Potassium, and Fluoride.


Green Tea and Bad Breath

The Japanese drink Green tea is known to suppress foul breath caused by certain foods. The deodorising effect of Green tea leaves has been known for centuries, and tea leaves traditionally have been used as deodorants. A study demonstrated the deodorising action of Green tea polyphenols in a test against methyl mercaptan, the compound most closely associated with halitosis. Green tea also has been shown to suppress bad smells produced by trimethylamine and ammonia.

Sencha (literally, roasted tea) indicates the past processing methods used to make this most popular of all Japanese Green tea. Today, sencha is initially steam treated before further processing with hot air drying and finally pan-frying. Over three quarters of

all tea now produced in the Japanese tea gardens are in fact graded as sencha, a tea selected for its pleasant sharpness and fresh qualities complementing a leaf of high uniformity and rich emerald colour.

However, the flavour, colour and general quality of sencha is highly variable, and depends not only on origin but also season and the leaf processing practises locally employed. It is well known that later harvests of sencha have more bitter qualities, a more robust flavour and generally less aroma. Furthermore, the leaf of late season teas is generally less uniform. Most regions make a number of kinds of sencha, which are named according to the kind of processing used. Sencha is the tea most likely to be offered in a Japanese household or restaurant.

Japanese production techniques have centred exclusively on perfecting and diversifying forms of Green tea, traditionally showing no interest in the fermented (black) tea much favoured by the Western tea drinker. Even so, a remarkable selection of teas is produced in Japan and much is made of regional and seasonal variations among the many kinds of Green tea available, particularly the higher grades of tea. Early season sencha, the new season tea or shin cha, are generally regarded as the best of each year's crop, and different regions compete on quality and seasonal availability.


All teas, Black, Green or Oolong, come from the leaves of the same plant known as the Camellia Sinensis. The basic difference is that Black Tea originated from fermenting the leaves while Green Tea is from unfermented leaves; Oolong is semi-fermented. The freshly picked Green Tea leaves are steamed to de-activate enzymes which cause fermentation or oxidation resulting in the maintenance of its green color. The process for the Green Tea production, picking time during the season and the difference in soil and climate conditions create the different types of Green Teas. Green Tea powder may also be used as a cooking additive and for Japanese Tea ceremonies.


Tea vs Toxins

Tea bags can cure "sick building syndrome" say Japanese researchers. People who move into a new house can suffer nausea and sore throats due to the chemicals from fresh paint and glue, with one of the chief culprits being formaldehyde. Now the Tokyo Metropolitan Consumer Center has found that unused tea bags scattered around the house soak up the formaldehyde, aided by tannin in the tea. They found that the concentration of formaldehyde in the air fell by between 60 and 90 percent. Black or Green tea bags are said to work best.

New Scientist

There are many types of Green tea, yet they all share one thing in common: NONE are prepared with boiling water! Any Green tea worthy of the name will turn bitter if it is brewed at too high a temperature. All Green teas should be brewed at between 80c and 90c. Convenient methods for achieving this are: (a) let the kettle sit for five or so minutes after boiling, before you pour the water; or (b) first add a dash of cold water over the dry leaf before adding the freshly boiled water; (c) take kettle off the boil when you see whisps of steam coming from the kettle. There is one other very important point to remember: NEVER OVER-BREW! Green tea only needs one to two minutes brewing at most (depending on the type of Green tea and the personal preference of the tea drinker).If you leave the Green tea brewing for too long, it will become bitter. The exception is when making iced tea - use double the amount of leaf, and add to cold water two or three hours in advance. Just before drinking add some ice and a little natural stevia to taste if sweetness is desired!

Please remember that Green tea leaves can be re-used. In fact, the Chinese believe that the second infusion makes a better cup of tea than the first! A good Green tea will provide at least three infusions. Just bear in mind when making subsequent infusions leave the water in contact with the leaf 20 seconds or so longer each time.

Adapted from

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