Why Tea is Good for Your Health
The Various Teas
Black tea, green tea, oolong (Wulong) tea, white tea and yellow tea, all come from the same evergreen plant Camelia sinensis. The differences lie in how each tea is processed. The tea leaves oxidize and wilt if not dried quickly after picking. As the chlorophyll in the leaves break down, the leaves progressively darken. This process of enzymatic oxidation is called fermentation in the tea industry even though in reality this is not fermentation. That is, no micro-organism is added to ferment the tea. Most teas in the West are usually tea blends from many areas.
The break-down is as follows: White tea is unwilted and unoxidized by picking and air drying; Yellow tea is unwilted and unoxidized but allowed to yellow; Green tea is wilted and unoxidized, picked, then heated (by steaming or pan frying) and drying the leaves; Oolong tea is wilted, bruised, and partially oxidized; Black tea is wilted, crushed, and fully oxidized; and , Post-fermented tea is Green tea that has been allowed to compost (decay).
Benefits of Tea
Tea leaves contain bioflavonoids (antioxidant plant pigments), amino acids, vitamins C, E, and K, caffeine and polysaccharides (complex carbohydrates such as cellulose, starch or glycogen). The benefit to tea drinkers is an improved immune system from beneficial intestinal microflora along with germicidal activity against bad bacteria. All tea leaves contain natural fluoride, and in conjunction with the flavonoids, helps to prevent tooth decay.
Both green and black tea contain many antioxidants that have anti-cancer, anti-mutant and anti-tumor attributes. It is well established that tea aids in normalizing blood pressure and preventing coronary heart disease by reducing lipids (fats). Helps to prevent diabetes by reducing blood glucose (blood sugar).
Green tea aids in reducing atherosclerosis (hardening of the arteries), LDL (the bad) cholesterol, cancer, inflammatory bowel disease, diabetes, liver disease, healthy weight loss, neurodegenerative diseases, as well as halitosis (bad breath).
Black tea reduces the risk of stroke by 70 percent. Researchers contribute this to the bioflavonoids that studies have linked to protection against heart attacks, cancer and other diseases. These bioflavonoids have antioxidant properties that reduce the ability of blood platelets to form clots, the main cause of strokes. Even though green tea is also high in bioflavonoids, its high vitamin K content may offset their anticlotting properties.
In the March 31, 2005, issue of the American Chemical Society’s Journal of Agriculture and Food Chemistry, researchers found that both black and green teas significantly inhibited cataract formation by decreasing glucose levels in diabetics. The study was based on the human consumption of less than five cups of tea per day.
The April, 2008 issue of Mayo Clinic Health Letter points out what is known about tea’s potential benefits. Green tea in particular, could be beneficial in reducing inflammation related to arthritis and slowing cartilage breakdown. It may also improve bone mineral density in older women. Plus, those who consume green tea daily show less risk of memory loss. The potential benefits seem to be in the tea cup and not in supplements or tea extract capsules.
Myths and Truths
1. Tea prevents iron from being absorbed from foods. Drinking tea will not result in iron deficiency. A daily cup of black tea, researchers in Germany have found, can help stop excess iron from damaging bodies of people who suffer from hemochromatosis (a disorder of iron metabolism that occurs usually in diabetic men). The high content of flavonoids, commonly mistaken for tannins in tea, limit iron absorption but does not prevent iron absorption. (If worried about it, squeeze a little lemon in your cup of tea to bloke iron absorption).
2. Fluoride in tea is harmful. No it is not. The tea plant accumulates fluoride from the soil. Fluoride is known to protect teeth from dental cavities. Tea is a natural source of fluoride, unlike the chemically produced fluoride from co-products of the phosphate fertilizer industry. [Fluoride is the single negatively charged ion of flourine containing antibodies specific for or capable of stimulating immune response. Fluorine, on the other hand, is a nonmetallic element that is a flammable, irrating toxic diatomic (2-atom) gas. Thus, fluorine is harmful but flouride is beneficial].
3. Tea contains as much caffeine as coffee. This is erroneous. Tea contains about a third of the caffeine in coffee. Small amounts of caffeine, as found in tea, offers a wide range of benefits. These include improved alertness, short-term recall and reaction time, positive mood and reduced levels of fatigue. Caffeine is beleived to impact on mood and performance by acting on neurotransmitters in the brain. Caffeine also enhances physical performance and, reduces the likelihood of Parkinson’s disease. Healthy weight loss, reduction in duration and severity of headaches and treatment of asthma symptoms are additional attributes of moderate caffeine consumption as found in tea.
4. Tea is dehydrating. Wrong. Tea contains approximately 99% water. Both the Food Standards Agency and the British Dietetic Association advise that tea can help to meet the daily fluid requirements. The European Journal of Clinical Nutrition dispels the common belief that tea dehydrates. Tea rehydrates as well as water, United Kingdom (UK) nutrionists found. Tea not only replaces fluids but also contains antioxidants beneficial to health.
5. Tea is a diuretic. Tea does not have a diuretic effect unless you drink 5 and 6 cups of tea at one sitting. Those who regularly drink tea do not experience an increased urine output, research shows, because a tolerances to caffeine develops over time.
6. Tea contains tannin (a substance that has a tanning effect). Tea does not contain tannins. What was originally thought to be tannin (a chemical that may increase risk of nasal and esophogeal cancer) in tea turned out to be flavanoids.
As mentioned by the U.S. National Cancer Institute, laboratory studies on animals showed that the flavonoids in green tea inactivated oxidizing agents before cell damage occured, reducing the number and size of tumors, and inhibited the growth of cancer cells.
From the Life Science journal Carcinogenesis, a study demonstrated that green tea along with tamoxifen is effective in suppressing breast cancer growth.
The University of Geneva and the University of Birmingham conducted clinical trials indicating whereby green tea raises metabolic rates, speeds up fat oxidation and improves insulin sensitivity and glucose balance. Besides caffeine, green tea also contains catechin polyphenols that raise thermogenesis (rate calories are burned), thus, increasing energy endurance.
City College of the City University of New York, found that the amino acid L-theanine, found exclusively in the tea plant, is absorbed by the small intestine and crosses the blood-brain barrier affecting the brain’s neurotransmitters boosting mental alertness by increasing alpha brain-wave activity, and resulting in a calmer, more alert state of mind.
In a research project at the Brigham and Women’s hospital, L-theanine was found to help the body’s immune system respond, when fighting infection, by increasing anti-bacterial proteins.
An article in the New Scientist magazine mentions the numerous studies of how green tea protects against many cancers, including lung, prostate, and breast cancer. The main reason given is the antioxidant epigallocatechin gallate (EGCG).
How to Prepare for Best Results
Green tea is steeped for about three minutes or less at 140-185 degrees Fahrenheit (60-85 degrees Celsius). As a general rule, bring water to a rolling boil (212 degreesF/100 degrees C). Take pot off of fire and let stand for one minute. This should be about the right temperature to pour water over tea in cup. Steep by placing saucer over mouth of cup for about 2 to 3 minutes. (White and yellow teas can be steeped for about 30 seconds to one minute, or not at all. Nonoxidized teas require less brewing).
Black tea should be brewed with water at the boiling point (212 degreesF/100 degrees C). Higher temperatures are required to extract the flavorful phenolic molecules found in fermented tea. Steep the tea for about 4 minutes but no longer than 5 minutes. Longer times will make the tea bitter.
Oolong tea (Wulong) should be brewed about 194 – 212 degrees F (90 – 100 degrees C). Can be brewed three to five times, the third steeping being the best. Unlike green tea, oolong improves with reuse. Brewing times are 30 seconds to two minutes.
In My Opinion
The health benefits of tea are hard to deny. From my own experience I know that when I drink tea, even one cup, I am energized the whole day. It is as if the energy is time-released but in a calm and even way. Not like coffee that jacks me up instatntly and later gives me the jitters. For me, I only add stevia as a sweetener (SweetLeaf Sweetener packet) to green tea. On days when I need more of a boost, I will add, besides the stevia, grated ginger, a dash of cinnamin and a dash of clove in my black tea (orange-pekoe). For a drink that has been around for over 4,000 years, you can only gain by adding tea to your daily routine. As a close second to water, tea is far superior to any other drink for rehydration and for health.