The delicate new leaves and buds of each new tea shoot contain ingredients that deliver a number of health benefits to our bodies. The most important of these are polyphenols, antioxidants that help prevent or neutralize the negative effects of harmful free radicals found in air pollution, a bad diet, smoking, too many UV rays, and stress on our bodies. Free radicals damage cells in the body and can cause life-threatening conditions such as heart disease, cancer, stroke, thrombosis, and more.
Luckily, all teas produced by the Camellia plant are chock full of polyphenols. By drinking plentiful quantities of tea throughout the day, we can help protect our health and stay well. In fact, according to tea researcher John Weisburger, tea has roughly eight to 10 times the number of polyphenols found in fruit and vegetables. The younger the tea leaves and buds when picked, the higher the level of polyphenols in them and therefore the more powerful the health benefits. Tea’s polyphenols are also what give teas their bitterness and astringency, so it is important to steep the leaves long enough to draw out the goodness but not so long that the liquor tastes bitter and unpleasant.
The Importance of Catechins
The most important polyphenols found in tea are catechins, which are a particular type of disease-fighting antioxidant and flavonoid, or oxygen-containing aromatic antioxidant compound. These are the key to the health benefits and these are the five catechins, which make up about 25 percent of the dry weight of a fresh tea leaf, that tea researchers typically focus on:
- epigallocatechin-3-gallate (EGCG): higher levels in green teas
- epicatechin (EC)
- epicatechin-3-gallate (ECG)
- epigallocatechin (EGC)
- gallocatechin (GC)
Although changes in polyphenols take place during the oxidation of black, oolong, and dark teas, research to date shows that all types of tea have the same potent antioxidant effect on our bodies, so we should drink a range of teas to receive the maximum benefit.
The Gentle Jolt
Perhaps tea’s best-known ingredient is caffeine, which acts as a stimulant, waking us up and keeping us alert throughout our waking hours. But the effects of the caffeine we absorb from tea are very different from those of the caffeine obtained from a cup of coffee.
Coffee delivers a sudden wake-up jolt to our circulatory system, causing our heart and pulse to race. The caffeine in tea, on the other hand, stimulates our senses in a much more gentle way, taking 15 to 20 minutes to find its way into our central nervous system, heightening our awareness and ability to focus, while leaving us completely calm.
This kinder, less aggressive boost to our wakefulness is due to the magic of tea’s less well-known component, L-theanine, an amino-acid that has so far been found only in the tea plant and in the bay bolete mushroom. Discovered in 1949, L-theanine helps to transmit nerve impulses in the brain, increasing the activities of the alpha waves and relaxing us without making us feel sleepy or drowsy. It is no accident that Zen Buddhist monks and priests have consumed tea for centuries to stay awake, focused, and serenely tranquil during long periods of prayer, chanting, and meditation.
The Benefits of Shade
While the buds and leaves are forming on the shoots, the level of L-theanine increases if the tea plants are heavily shaded, as occurs in the production of Japanese gyokuro (玉露) and matcha (抹茶). Why? During normal photosynthesis, L-theanine is converted to catechins. Under less shade, however, photosynthesis slows so the tea retains more of its naturally occurring amino acid L-theanine. There are more than 20 amino acids in tea, and each adds to the sweetness and brothy, velvety, umami character of tea liquor.
More Health Perks
Tea also contains theobromine and theophylline, which act as stimulants that help to dilate blood vessels and stimulate the heart, thus keeping our circulatory system running efficiently. Likewise, there also are traces of the following vitamins and minerals, which are essential to general good health:
- calcium: boosts bone health, as well as protects against cancer, diabetes and high blood pressure
- zinc: aids in proper growth and immune function
- iron: helps transport oxygen throughout the body, as well as maintains healthy cells, skin, hair, and nails
- copper: aids in the formation of collagen, increases the absorption of iron, and plays a role in energy levels
- potassium: helps your heart beat efficiently, your nerves work, and your muscles move, as well as aids your kidneys in filtering blood
- phosphorous: encourages bone health, better digestion, an improved energy
- manganese: benefits healthy bones, blood sugar control, and healthy skin
- magnesium: helps in the the transmisison of nerve impulses, detoxification, energy production, regulation of body temperature, as well as healthy bones and teeth
- fluoride: strengthens tooth enamel
- Vitamins B2, B6, and B12: aid in the metabolism of carbohydrates
- Vitamin C (found in sencha): helps reduce stress, fight infection, and strengthens the immune system
- Vitamin E: helps slow the aging process
- Vitamin K: plays an important role in blood clotting, but also aids in building strong bones and preventing heart disease
There is no doubt that by drinking regular quantities of tea, we feed our bodies with regular supplies of useful, beneficial antioxidants, minerals, vitamins, caffeine and the magical, calming L-theanine.