During infusion, some chemical elements, such as vitamin C, are destroyed, whereas others are more easily dissolved into the liquid. Roughly speaking, a cup of tea is composed of several hundred active substances. While tea leaves contain the components found in every living organism (proteins, carbohydrates, amino acids and the like) and those characteristic of plant species (such as chlorophyll and cellulose), it is the presence of polyphenols and alkaloids that gives an infusion of tea leaves such astonishing properties.
- Polyphenols – group of phenols that make up a family of organic molecules. In tea, these phenols are found in the catechins in which epigallocatechin gallate (EGCG) is the main component. Commonly known as “tannins” and having astringent properties that make living tissues contract, these polyphenols give tea its astringency, strength and thickness. Research shows that the abundant presence of catechins (molecula of polyphenol) in green tea may act as a powerful antioxidant – thereby neutralizing free radicals – which may have help prevent the effects of ageing and the onset of illnesses such as cancer and cardiovascular disease.
- Alkaloids – naturally occurring heterocyclic organic molecules that contain nitrogen and are found in amino acids. Three kinds of alkaloids are found in tea, the main one being caffeine.
Caffeine (Theine) – Theine and Caffeine are the same alkaloid. Caffeine in tea bonds with different substances in the liquor namely tannins, which attenuate and stabilize its effect. Tannins prevent caffeine from being released rapidly, so it is absorbed over a longer period of time. The effect, therefore, lasts longer and is more regular.
In tea, caffeine stimulates the central nervous system and the cardiovascular system by enlarging the diameter of the vessels in the cerebral cortex. When ingested in coffee, caffeine has a direct effect on blood circulation through the coronary system, stimulating an acceleration of the heart rate.
In other words Tea is a more of a stimulant than an excitant. It sharpens the mind, increases concentration, eliminates fatigue and enhances intellectual acuity.
- Nutrients – Tea leaves are 20% proteins, but only 4% of those proteins, present in the form of albumin, are water soluble. In addition, just like the proteins, only a small percentage of the carbohydrates in tea are soluble in water. Just one carbohydrate, monosacharide, is soluble, making tea a low-calorie drink that contains only one or two calories per cup.
Tea also contains some 20 amino acids, including theanine, which accounts for 50 -60% of these amino acids.
Tea also contains many vitamins (including A, B complex, E, K and flavonoids) about 30 minerals (including potassium, phosphorus, iron, magnesium and calcium), chlorophyll and hundreds of aromatic components.
Healthy benefits of tea:
- It supports the heart system
- It activates circulation
- It helps detoxification
- It fights hypertension
- It reduces fatigue
- It slows the ageing process
- It helps prevent certain types of cancer
- It helps digestion
- It reduces cholesterol
- It balances body temperature
- It strengthens the immune system
- It enhances concentration
- It reduces the risk of tooth decay
White tea – consumed mainly in summer in China for its cooling properties.
Green tea – green tea has more polyphenols than other tea families. It prevents certain forms of cancer, enhance intellectual performance. It contains more iron, vitamins and catechins than black.
Wulong tea – stimulating the metabolizing of lipids. Antistress, even euphoric effect is due to the high concentration of aromatic oils, which are drawn out from the leaves during rolling.
Black tea – the enzymatic oxidation undergone converts some of the catechins into theaflavins and thearubigins and destroys some of the vitamins. On the other hand the caffeine in black tea is released more rapidly into the bloodstream over a shorter period compared to green tea as oxidation partially separates it from the tannins. This means the black tea is more effective as a physical stimulant than green tea.
Pu Erh tea – Pu Erh has been used as a dietary supplement by many nomadic tribes. As these people ate mostly very fatty yak meat, tea allowed them to balance their diet, counteracting the fat. Today Pu Erh teas are recognized as helping specifically to regulate the body and stimulate digestion, it also helps eliminate cholesterol from the body.
Iron absorption – Tea facilitates digestion by stimulating the elimination of fats. On the other hand it can inhibit the absorption of iron and calcium from foods. For this reason, drinking tea with meals is not recommended, nor is during the half hour before or after a meal.