Green Tea

Green tea is a stimulating drink that comes from infusing the leaves of the tea plant, Camellia sinensis. There are three types of tea depending on the level of fermentation: green (unfermented), oolong (semi-fermented) and black (fermented). Green tea is produced by drying the leaves at high temperatures so that oxidative enzymes are inactivated and the polyphenol content remains intact. The most important polyphenols in tea are catechins.

If we stick to the definition of tea as a product obtained from the leaves of Camellia sinensis or assamica, there are five main types of tea: white, green, red and black, although their varieties give rise to more than 3000 classes.

Main components

Green tea, at a nutritional level, contains amino acids (aa) (which are the components of proteins): theanine, valine, arginine, asparagine, glycine, leucine, niacin, lysine, histidine. Tea leaves contain minute amounts of fat and a part of fiber, including pectins.

At the mineral level, it provides us with: sulfur, calcium, copper, iron, magnesium, phosphorus, potassium and fluorine. And regarding vitamins, tea leaves contain vitamin C and vitamin B3 or niacin. In any case, it should be considered that these vitamins are heat sensitive, especially vitamin C, therefore it will not be the best drink to provide us with vitamin C.

In addition to the components already mentioned, tea has caffeic, chlorogenic, cinnamic, phenylacetic, gallic, malic, oxalic, salicylic acid in the leaves, and lauric and linoleic acid in the seeds. Contains alkaloids: caffeine, in leaves and young shoots and theobromine in leaves. Essences such as carvacrol, geraniol and thymol, and polyphenols such as catechins, epicatechins gallate, tannins ...

Medical uses

Polyphenols are natural chemical compounds found in certain foods. A subgroup of polyphenols, catechins, are antioxidant substances. The way green tea is processed greatly affects the catechin content of the finished tea. The catechins in green tea account for 15-30% of its dry weight.

In the case of oolong tea 8-20% and black tea 3-10%. Several studies have shown that one of the catechins in green tea (epigallocatechin gallate) has an inhibitory action on the activity of urokinase, an enzyme necessary for the reproduction of cancerous tumors. These polyphenols, according to some studies, have antioxidant, anticarcinogenic, anti-inflammatory, thermogenic, probiotic, and antimicrobial properties.

Green tea also has other flavonoids (quercetol, kenferol, myricetol). These compounds are essential in the absorption and metabolism of ascorbic acid (Vitamin C) and increase capillary resistance (vasoprotective action).

These compounds are significantly lost during the black tea making process (remember fermentation). In vitro experiments suggest that regular consumption of green tea lowers LDL cholesterol levels and that the powerful antioxidant effects of green tea inhibit the oxidation of this type of cholesterol.

Green tea also contains xanthic bases, mainly caffeine that acts as a stimulant of the nervous system, inhibiting sleep and reducing the feeling of fatigue. It is prescribed to counteract migraine headaches, drowsiness, and mental fatigue.

On the other hand, theophylline (and to a lesser extent caffeine) generates an increase in cardiac and coronary frequency and output. It is a known bronchodilator prescribed to relax the smooth muscle of the bronchial tubes in the treatment of bronchial bronchospasm, bronchitis and emphysema. Another methylxanthine found in tea is theobromine.

This acts as a diuretic, vasodilator, cardiac stimulant and smooth muscle relaxant.

Contains tannins, with astringent properties. This allows to indicate green tea in cases of diarrhea, in the same way in which the consumption of black tea is indicated.

How to take it

It can be taken in the most traditional way, simply as an infusion. But to this infusion you can add sugar, lemon, mint, as in the traditional green tea with spearmint that is prepared in Morocco by adding a good amount of sugar and a few sprigs of fresh spearmint to the tea.

In addition to taking it as it is as an infusion, it can be made as a sorbet or granita, a cold drink or even ice cream.

Who is it suitable for?

• Students: because of its stimulating capacity, green tea can be used to better cope with times of study or intense work.
• Athletes: its caffeine content makes it a good option as a pre-exercise drink, mainly.
• Need for rehydration: although in serious conditions of the digestive system, rehydration is ideal to be done with serum, if we simply want to hydrate on a hot day, after an exercise session, etc. Tea is a good ally to help us drink enough liquids, either hot or cold.
• Preventive: due to its antioxidant properties, its consumption seems appropriate as a preventive substance for carcinogenic processes.
• Fluid retention: green tea favors the elimination of urine, so it can be very interesting in people who want to stimulate diuresis.

It is not suitable for

• Gastritis or gastric ulcer: green tea is not indicated in these cases since it contains irritating compounds of the gastric mucosa such as tannins.
• Anxiety, insomnia, nervousness or tachycardia: its caffeine content makes it inadvisable in such cases since caffeine acts as a stimulant of the nervous and cardiorespiratory system. These effects are not exclusive to green tea, as they are with black tea or coffee.
• Be advised against stimulants: green tea, like black tea or coffee, can cause a certain degree of addiction, if its consumption is frequent.

Buying and conservation advice

When buying tea we will pay attention to the fact that the container has not allowed the tea leaves to get wet and they are kept very dry and as whole as possible. In addition, to acquire a tea it is important to take into account and know the multitude of varieties of tea that exist, not only because of the multitude of combinations of Camellia sinensis and Camellia assamica leaves with other ingredients or because of their different types of collection and treatment.

But also by the use of different parts of species, different from the previous two, to make drinks also called tea.

Main varieties of green tea

• The Lung Ching: (Dragon pit) Very famous variety and of the highest quality. Sweet and golden.
• The Gunpowdwer: Tea rolled into little balls. Popular in Morocco where it is boiled with mint and sugar.
• Youg Hyson: Green tea with young leaves and strong flavor.
• Sencha: Very popular in Japan, it is yellow in color and tastes like vegetables.
• Matcha: Powdered green tea, with a refreshing power, served sparkling in the tea ceremony.
• The Bancha: Made from large leaves. Contains little caffeine. It tastes slightly like hay.
• Gyokuro: Its very mild cut grass flavor has made it very popular in Japan.