- Neutralizing cancer causing agents
- Protecting cells against mutation from cancer causing agents
- Protecting against free radical damage
- Protecting against cellular damage from ionizing radiation
Green tea may protect against cardiovascular disease in several ways:
- Inhibition of abnormal clotting inside vessels (by at least two separate mechanisms).
- Reduction of total cholesterol and elevation of HDL cholesterol.
- Reduction of high blood pressure by inhibition of angiotension-converting enzyme.
- Inhibition of the oxidation of LDL cholesterol within the lining of the arterial wall.
Green tea has also demonstrated an ability to reduce blood glucose levels, inhibit bacteria and viruses and act as a general antioxidant.
Drink several cups of green tea with each meal or take two green tea extract capsules daily.
What Else Can Green Tea Do?
Green tea polyphenols are potent antioxidants, especially in the brain. Some studies show that the polyphenols most prevalent in green tea (the catechins) are far more potent in suppressing free radicals than vitamins C or E. Green tea can kill bacteria. Taking green tea with meals may reduce the risk of bacterial food poisoning. Drinking green tea may kill oral bacteria that causes cavities and bad breath. Green tea also is effective against a strain of staph that has become antibiotic-resistant. Green tea promotes the growth of friendly bifidobacteria in the intestine and prevents the growth of dangerous intestinal bacterial strains such as clostridia and E. coli.
The polyphenols in green tea suppress the production of an uremic toxin (methylguanidine) to improve the clinical appearance of the kidney after renal failure. A human study showed that the toxic compound methylguanidine decreased significantly one month after the administration of green tea polyphenols. Six months later, the mean methylguanidine level was about 70% of what it had been at the initiation of treatment.
The Japanese drink green tea to suppress foul breath caused by certain foods. The deodorizing effect of green tea leaves has been known for centuries, and tea leaves traditionally have been used as deodorants. A study demonstrated the deodorizing 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.
Historical Uses
- Used primarily for its free radical fighting capabilities
- EGCG protects against digestive and respiratory infections
- Helps block the cancer-promoting actions of carcinogens, ultraviolet light, and metastasis
- High total and LDL-cholesterol levels
- High blood pressure (suppresses angiotensin I converting enzyme)
- Reduces platelet aggregation
- Inhibiting pathogenic bacteria that causes food poisoning
- Blocks the attachment of the bacteria associated with dental caries to the teeth
New Findings on Green Tea
Disease Prevention
Epidemiological studies show that people who drink green tea have significantly lower risks of many diseases, including cancer, heart disease and stroke. Laboratory studies show that green tea extract protects against, and may be an effective treatment for many common degenerative diseases.
The active constituents in green tea are the catechin polyphenols. Green tea catechins are potent antioxidants that provide health benefits beyond their ability to neutralize free radicals.
The ability of green tea to prevent cancer is so well established that new studies are testing green tea as a potential cancer therapy. Green tea may be especially protective against lung cancer in former and current cigarette smokers. Its lung cancer protective effects are of significant importance based on new studies showing that former smokers are at greater risk for developing lung cancer than was previously thought.
Green tea catchins have been shown to prevent cancer in the following ways:
- They help to neutralize dietary carcinogens such as nitrosamine and aflatoxin.
- They interfere with the binding of cancer-causing agents to cellular DNA, thereby protecting cells against mutations that can eventually cause cancer.
- They protect against free-radical DNA damage that causes some cancers.
- They inhibit bacterial-induced DNA mutations that also can lead to certain cancers.
- They work with enzymes and other antioxidants in the intestine, liver and lungs to prevent the activation of certain carcinogens before they damage DNA.
- They protect against the effects of ionizing radiation and ultraviolet radiation.
Green tea has been shown to counteract both the initiation and promotion of carcinogenesis. Some studies have shown that green tea blocks the formation of certain tumors. If green tea's only benefit were to reduce the risk of cancer, it would be well worth taking as a beverage or supplement.
Protecting Against Cardiovascular Disease
Heart disease and stroke are associated with a number of risk factors. The surprising news is that green tea appears to mitigate many of these risk factors.
Green tea has been shown to lower LDL cholesterol and serum triglyceride levels. The potent antioxidant effects of green tea inhibit the oxidation of LDL cholesterol in the arteries. The oxidation of LDL cholesterol plays a major contributory role in the formation of atherosclerosis.
The formation of abnormal blood clots (thrombosis) is the leading cause of heart attack and stroke, and green tea has been shown to inhibit abnormal blood clot formation as effectively as aspirin. When looking at coagulation risk factors in the blood, green tea specifically inhibits platelet aggregation and adhesion via effects that differ from those of aspirin.
Green tea reduces the risk of arterial blood clotting by two known mechanisms. First, green tea inhibits another clotting agent called platelet activating factor (PAF). Reducing thromboxane A2 levels is highly desirable. Thromboxane not only causes arterial blood clots, but also causes arterial constriction. The inhibition of thromboxane can prevent a heart attack or a thrombotic stroke.
Green tea also has been shown to elevate levels of HDL, the good cholesterol that helps remove atherosclerotic plaque from arterial walls.
Note that aspirin has some anti-thrombotic effects that differ from green tea, such as inhibition of cyclooxygenase. If you are taking low-dose aspirin to prevent a heart attack or stroke, you should continue doing so even if you also consume green tea.
If you are going to use green tea to lower cholesterol, triglycerides or thrombotic risk factors, make sure you have your blood tested and evaluated by a competent medical professional.
Lowering Blood Pressure
The loss of arterial elasticity is one cause of high blood pressure. Youthful arteries expand and contract effortlessly with each heart beat. Aging causes a loss of arterial elasticity. As noted above, green tea inhibits thromboxane production, which is one cause of arterial constriction. A more significant cause of hypertension is an enzyme secreted by the kidneys called angiotension-converting enzyme (ACE). Popular drugs such as Capoten, Vasotec and Zestril function as angiotension-converting enzyme inhibitors (ACE inhibitors). By blocking the effects of ACE, blood pressure is reduced significantly in most hypertensives. Green tea is a natural ACE inhibitor. Published studies show lowered blood pressure in animals and humans given green tea extracts.
If you are going to use green tea to treat hypertension, do so only under the supervision of a competent medical professional who can evaluate whether it is working for you. Regular blood-pressure testing is mandatory.
Lowering Blood Sugar Levels
When starch is consumed, It requires the enzyme amylase to break it down into simple sugars that can be absorbed in the blood stream. Green tea polyphenols inhibit amylase. One study showed that just one cup of green tea inhibited amylase activity by 87%. Another study showed that green tea extract reduced the normal elevation of glucose and insulin when 50 grams of starch were ingested.
High blood levels of glucose and insulin predispose people to diabetes and cardiovascular disease, and are associated with accelerated aging. For many people, sugar is the primary culprit in the accumulation of body fat. One animal study showed a significant reduction in body fat in response to green tea catechin supplementation.
