Recent studies have shown that teas, especially green tea, have benefits beyond their wonderful flavors and aromas.
The Chinese have known about the medicinal benefits of green tea since ancient times. References to tea in Chinese literature go back approximately 5,000 years. Ancient folklore place the beginning of brewing tea as a beverage at 2737 BC, when a camellia blossom drifted into a cup of boiled drinking water belonging to Emperor Shen Nung. At various times throughout history, China’s national drink has been designated as the state currency and at times used as cash. The elevation of tea drinking to an art form began in the eighth century, with the publication of Lu Yu’s “The Classic Art of Tea”. His work contained several practical tips for manufacturing tea, many of which are still in use today.
Even with the vast variety of choices, tea lovers today are surprised to learn that all tea comes from the same source: the Camilla Sinensis bush. And while there are hundreds of varieties of teas most fall into four basic categories based on their processing. The four categories are green, black, oolong, and scented. Only green tea is steamed, which prevents the leaves’ compounds from being oxidized by fermentation. Steaming causes no loss or weakening of the medicinal qualities of the leaves. Black teas are made from fermented leaves and oolong teas are partially fermented. Scented teas are made by mixing various flowers and petals with green (non-fermented) or oolong (partially fermented) teas.
Tea leaves consist of 75-80% water. The remaining components, catechin, caffeine, amino acids, vitamins and minerals, help form the variety of flavors. The primary medicinal value of green tea lies in the fact that it is rich in catechin polyphenols. Catechins are powerful, water-soluble antioxidants. Tea contains four main catechins: EC, ECG, EGC and EGCG. Researchers believe that catechins are effective medicinally because they easily stick to proteins, blocking bacteria from adhering to cell walls and disrupting their ability to destroy them. This blocking mechanism provides extensive health benefits by protecting the body from cancer, rheumatoid arthritis, high cholesterol, cardiovascular disease, infections and impaired immune function.
EGCG (epigallocatechin gallate) is the most powerful of green tea’s catechins. As an antioxidant it is 25-100 times more potent than vitamins C and E. One cup of green tea provides 10-40 mg of polyphenols and has antioxidant effects greater than a serving of broccoli, spinach, carrots, or strawberries. EGCG detoxifies by connecting with poisonous substances and harmful heavy metals (lead, chrome, mercury, etc.) and dissolving them. EGCG is also effective in lowering LDL cholesterol by connecting with it and absorbing and blocking it. This prevents the narrowing of blood vessels and inhibits the abnormal formation of blood clots (thrombosis), which is the leading cause of heart attack and stroke.
One cup of green tea contains about 15-30 mg of caffeine, depending on the age of the leaves at picking time. Young buds contain higher amounts of caffeine than mature buds. Caffeine provides health benefits as a stimulant and as a detoxifying diuretic. It also activates blood circulation. When caffeine is taken together with exercise, body fat is metabolized as an energy source rather than depleting glycogen stores. If caffeine is not desired there are processed decaffeinated teas available. Decaffeinated tea undergoes one of two processes. The first uses a solvent (ethyl acetate) and retains only 30% of the polyphenols. The second is a natural process using only water and carbon dioxide, called effervescence. It retains 95% of the healthy polyphenols. Dr. Andrew Weil, noted doctor and nutritionist, has a simple home solution for decaffeinating tea without losing the valuable nutrients. He suggests steeping the tea for 45 seconds in hot water and then pouring off the liquid. Next, add more hot water and steep as usual. Up to 80% of the caffeine is released in the first diffusion, with very little flavor and aroma being lost.
There are about 20 different types of amino acids in tea. More than 60% of these amino acids consist of theanine, which is unique to green tea because the steaming process does not eliminate it. Theanine counteracts caffeine and lessens its effect as a stimulant. L-theanine is a healthy amino acid found only in tea plants and certain mushrooms. In addition, green tea contains many helpful vitamins: A (promotes good vision), B1 (metabolizes sugars), B2 (builds red blood cells), B3 (releases energy from foods), C (antiviral/antibacterial), E (prevents heart disease), and F (prevents tooth decay).
In recent years more than 500 studies have been conducted worldwide to research the potential health benefits of green tea. With the myriad of benefits being discovered one “Ancient Chinese Proverb” can easily be called a “Modern Chinese Proverb” as well:
“Better to be deprived of food for three days, than tea for one.”