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Can you guess which drink is among the most consumed? Yes, it’s tea. Whether it is green, black, herbal or fruit tea, this particular drink is very popular all over the world.
Among all teas, green tea stands out with the most beneficial effects on human health. However, we are not talking about cheap bagged “teas”, we are talking about quality loose ones.
What effects does green tea have on the human body and how to prepare a perfect cup of tea?
It is estimated that about 2.5 million tons of tea leaves are produced worldwide each year, with green tea accounting for 20% of the total production. That’s pretty decent, right?
Green tea is made from the leaves of the Camellia Sinensis (Chinese tea tree) plant , which is also used to make white, black and oolong tea. The raw material is therefore the same, but the difference between the individual types of tea lies in the method of processing the tea leaves.
To make green tea, freshly harvested leaves are immediately steamed to prevent fermentation. This steaming process destroys the enzymes responsible for breaking down the color pigments in the leaves and allows the tea to retain its green color during subsequent rolling and drying.
Thanks to this method of processing, green tea retains the maximum amount of substances beneficial to health.
Green tea is made from mature tea leaves with minimal processing. It is unfermented and during its production only the leaves are steamed and then dried. Thanks to the gentle processing method, it retains its green color and most of the substances beneficial to health (especially antioxidants).
Oolong tea is made from partially fermented ripe tea leaves. It is darker and stronger.
Black tea is made from fully fermented ripe leaves. It is dark and strong.
White tea is made from very young tea leaves and buds that have not yet turned green, and the only processing is drying.
The composition of green tea is complex, yet it is important to highlight a specific compound. Green tea stands out for its content of polyphenols known as catechins , which belong to the group of antioxidants. Catechins make up about 12-24% of the total weight of dried tea.
There are four main catechins found in green tea: epicatechin, epigallocatechin, epicatechin gallate, and epigallocatechin-3-gallate. The best known and most effective of these is epigallocatechin-3-gallate (EGCG) responsible for most of the positive effects of green tea on human health.
There is no doubt that green tea has many positive health benefits. Drinking 2 to 3 cups of green tea a day is associated with a reduced risk of heart disease, stroke, and type 2 diabetes. 1 However, green tea also has other benefits. Which ones are they?
Green tea contains a number of natural stimulants and the main one is caffeine . Caffeine blocks receptors for adenosine, the chemical messenger in the brain responsible for feeling sleepy and tired. Caffeine has a similar structure to adenosine, so it can bind to adenosine receptors, thereby blocking adenosine’s effect on nerve activity.
The effect of caffeine is to delay fatigue and increase the feeling of alertness until the caffeine is broken down from the body. This is exactly the main reason so many people regularly consume caffeine in the form of a cup of coffee – to stay awake and mentally alert, focused on work.
Although the amount of caffeine in green tea is much lower than in coffee, it is still effective for maintaining alertness and concentration. One cup of coffee contains approximately 100 to 200 mg of caffeine, while a cup of green tea contains about 35 to 50 mg of caffeine .
The advantage of green tea is that its consumption is not associated with the unwanted side effects of consuming caffeine in the form of coffee, such as nervousness, headache and tremors.
But caffeine is not the only stimulant in green tea. Green tea contains an amino acid called L-theanine , which helps reduce stress and improve mood. 2 Research shows that L-theanine in combination with caffeine improves brain function, enhances memory and increases attention.
According to recent studies, regular consumption of green tea reduces systolic and diastolic blood pressure . This is thought to be related to green tea’s vasodilation (vasodilation) effects 10 by increasing the bioavailability of nitric oxide.
The catechins in green tea also help lower total and LDL cholesterol levels in the body, known as “bad cholesterol,” which can cause plaque to build up in the arteries and increase Heart attacks and strokes. Both the reduction of blood pressure and the reduction of cholesterol levels in the body contribute to the prevention of cardiovascular diseases.
The mechanism of action of green tea on cholesterol in the body is not yet fully understood. But epigallocatechin-3-gallate (ECGC) in green tea is thought to affect bile acid circulation, which helps regulate cholesterol metabolism.
Green tea is an important antioxidant. Antioxidants are compounds that protect the cells of the human body from the harmful effects of free radicals (reactive forms of oxygen). Stress, poor air quality, excessive sports load, aging or a number of common diseases – these are all factors that increase the production of free radicals.
Free radicals are produced naturally and almost continuously in the body
Our body fights them with its own antioxidant systems and maintains a healthy balance. But if there are too many of them, a problem arises. An imbalance between antioxidants and the formation of free radicals results in oxidative stress, which leads to cell damage.
Reactive oxygen species begin to attack cells and can lead to the development of a number of different diseases and damage to the DNA structure, thus accelerating the aging process.
Health problems associated with oxidative stress include heart disease, neurodegenerative diseases (Parkinson’s disease, Alzheimer’s disease), atherosclerosis, chronic fatigue syndrome, depression, autoimmune disorders, cancer and inflammatory diseases .
The catechins (especially EGCG) in green tea act as powerful antioxidants that have the ability to scavenge free radicals and protect the cells of the human body from oxidative damage. Together with antioxidant vitamins ( vitamins C and E ) and antioxidant enzymes (superoxide dismutase and catalase), catechins contribute to the body’s overall antioxidant defense system, which prevents related health problems.
Some studies have shown that green tea can increase your metabolic rate , which could lead to faster fat burning. But don’t look for a miracle in this. The impact of drinking green tea on weight loss is not as important as healthy eating and regular exercise.
Furthermore, most of the studies that showed small changes in metabolic rate used highly concentrated green tea extracts (extracts). We don’t even come close to meeting similar doses by regularly sipping green tea.
Green tea by itself is not a miracle for weight loss, but if you add it to a healthy diet with a slight calorie deficit and regular exercise, it will support the weight loss effect and you can lose a little more weight as a result.
Green tea can not only improve brain function in the short term, but can also protect the brain during aging. The catechins contained in green tea are responsible for these effects.
Several studies show that the catechin compounds in green tea may reduce the risk of dementia as well as neurodegenerative diseases such as Alzheimer’s disease and Parkinson’s disease. 17, 18, 19
Green tea in cosmetics increases skin hydration, retains moisture and prevents the formation of wrinkles . Green tea contains antioxidants that may be responsible for its regenerative properties.
In addition, it can be a good helper in the fight against acne, as it has an anti-inflammatory effect, participates in reducing the production of sebum 20 and prevents the proliferation of bacteria known as Propionibacterium acnes 21 .
Disclaimer: If you have been diagnosed with iron deficiency anemia, you should be careful with green tea consumption. Green tea contains natural compounds called tannins that interfere with iron absorption. For this reason, it is advisable not to drink tea with iron-rich food, drink green tea between meals, and not eat for at least one hour after drinking green tea. Also, pregnant and lactating women should limit their consumption of green tea to 1 to 2 cups per day.
In order to get the most out of green tea, we need to pay attention to several principles. This is mainly about the quality of the tea, its correct preparation, sufficient amount of tea leaves and regularity in the use of green tea.
The water temperature and tea steeping time have a significant effect on the antioxidant content and taste properties of the tea.
Recommendations regarding the optimal daily dose of green tea vary widely. In scientific studies, 3-5 cups of green tea are most often used, which can be considered optimal.
If you can’t imagine drinking 3 or more cups of tea a day, you can try green tea extract. The effects are similar, but the extract is more concentrated, and you need to pay attention to the dosage.
No food alone will bring positive effects in a day or a week. The same goes for green tea. If you want to benefit from the beneficial effects of green tea, you must consume it regularly.
Green tea can have a number of health benefits.
However, it will not correct an inappropriate lifestyle by itself.
It should therefore only be a supplement to a nutritionally balanced diet combined with regular exercise, sufficient sleep and elimination of stress.