Green Tea - An effectful drink for our health ?

Active ingredients and effects

Before we turn to the prophylactic and therapeutic effects of green tea in individual diseases in detail, we should first look at the active ingredients in green tea.

EGCG (epigallocatechin gallate)

EGCG seems to be the most effective ingredient in green tea, with almost miraculous properties in the prevention and treatment of many diseases. This ingredient therefore deserves special attention.

EGCG has two gallate groups, making it the most effective catechin.[1] In a study on the oxidation of lipoproteins, catechins had a 20-fold higher antioxidant effect than vitamin C, making catechins a very important antioxidant.[2]

Polyphenols also neutralise free radicals, superoxide radicals and peroxynitrites, they influence the activity of enzymes that promote oxidation and modify the phosphorylation of proteins.[3]

The flavonoid, which is abundant in green tea, unlike in black tea, has been proven in several studies to have an inhibitory effect on cancer growth and a protective effect in diabetes, multiple sclerosis and others.

EGCG also has anti-inflammatory properties, as we know from aspirin.[4] This prevents vascular occlusions and thus counteracts cardiovascular diseases, including heart attacks, cerebral apoplexy and angina pectoris.

Tabular presentation of the EGCG effect



Cardiovascular disease

Inhibition of blood clotting

Reduction of blood sugar level



Inhibition of cancer growth

Caries/periodontal disease

Polyphenol inhibits the enzymes of the bacterium Streptococcus mutans, which promote the development of dental plaque

Viral diseases

Antiviral effect, such as influenza viruses that cause flu and fever,


Possibly the same effect as above – already used in the treatment of AIDS patients





Flavonoids are phytochemicals which have great benefits for our health and are particularly abundant in green tea. Flavonoids reduce the risk of blood clotting, lower cholesterol and normalise high blood pressure. They therefore offer highly potent protection for our cardiovascular system. They also reduce the risk of breast, colon and stomach cancer.


Tannins belong to the group of polyphenols and are used in the treatment of gastrointestinal disorders. They convert proteins into molecules and thus deprive parasites of food. Tannins have a calming effect on the gastrointestinal tract; applied externally, they can strengthen the skin and make it more resistant to environmental influences.


First and foremost, they contain high levels of natural vitamin C, which is the structural vitamin in our body and undoubtedly one of the most important vitamins. It also strengthens our immune system, prevents atherosclerosis, lowers bad cholesterol and has anti-inflammatory effects. The vitamin B or thiamine contained in green tea also keeps our spirits fresh and increases our ability to concentrate.

Essential oils

Green tea not only has a positive effect on our physique, but also on our psyche. This is due to the essential oils contained in it, which we absorb as an aroma through the nose.  These aromas can create deep relaxation by decoupling our movement centre from the mental side, our thoughts and our moods. This allows our muscles to relax, despite stimulating trains of thought that otherwise act directly on them, leading to muscle tension – this enables deeper physical relaxation, even when you are also experiencing mental tension.

Bitter substances in tea

The bitter substances in green tea sensitise our taste buds and train our taste to react accordingly to natural foods. It is well-known that people in industrialised countries are less sensitised due to the industrialisation of food and simply react differently to taste. The bitter substances in green tea can restore the natural sense of taste.


The caffeine in green tea is gradually released, which prevents sudden caffeine peaks and compared to coffee or cola, ensures a mild yet long-lasting stimulation. The tannins in green tea are responsible for the gradual dosage, which release the alkaloid, which is responsible for the impulsive effect, slowly and generously in the bloodstream.


Saponins are herbal glucosides that have a positive effect, and not only on the gastrointestinal area. Thus, the saponins contained in green tea can bind to fats, prevent them being transported into the blood and thus counteract high cholesterol levels. In addition, they can relieve rheumatic complaints, solve cough mucus and, when used externally, treat skin and athlete's foot disorders.

In addition, saponins can promote the absorption of other plant compounds and increase their effect.


Manganese is involved as part of many enzymes in energy conversion and is essential for the formation of connective tissue and bone. Manganese transports the calcium into the bones. Thus, green tea can very successfully counteract osteoporosis.

[1] Guo et al., 1999

[2] Vinson et al., 1995

[3] de Groot and Rauen, 1998; Chen and Ho, 1995 Middleton, 1998

[4] Dr. Jörg Zittlau: Grüner Tee für Gesundheit und Vitalität (‘Green Tea for Health and Vitality’), 1997, p. 36