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What are Antioxidants?
Antioxidants are nutrients found naturally in the body as well as in plants such as fruits & vegetables. Tea contains high quantities of antioxidants, however the better quality the tea and the fresher the leaves the higher concentrations will be.
This is why it is important to drink a good, fresh, whole leaf tea as opposed to the dust in tea bags. It would be wrong to say that ‘tea-bag-tea’ did not contain any goodness, however because of the number of processes it has been through and the fact that it has been ground up, many of the molecules the antioxidants are based on will have been destroyed.
Common antioxidants found in tea include compounds called polyphenols. Included within the broad antioxidant polyphenol class are flavonoids and catechins. The most important dietary sources for flavonoids are fruits, tea and soybean.
Flavonoids
Flavonoids are a class of water-soluble plant pigments and it is the catechin called Epigallocatechin-3-gallate (EGCG) in Green Tea that is particularly beneficial. EGCG contains 3 phenol rings and therefore has very strong antioxidant properties.
EGCG is the main active component in Green Tea leaves. Black Tea leaves also contain EGCG but in much lower quantities. Studies have shown that Green Tea has 5 times the EGCG content of regular tea. This is because Black Tea leaves are fermented, during which many of the catechins are oxidized to darker coloured molecules (theaflavin and thearubigen).
EGCG possess the most potent antioxidant activity of the catechins. ECGC may provide health effects by protecting our cells from oxidative damage from free radicals. A number of chronic diseases have been associated with free radical damage, including cancer, arteriosclerosis, heart diseases and accelerated aging. ECGC interferes with many enzyme systems: it inhibits fast-binding and reversible fatty acid synthesis, increases tyrosine phosphorylation of the insulin receptor, activation of ornithine decarboxylase. ECGC can protect the DNA in the human cells from ultraviolet and visible radiation-induced damage. ECGC may be effective in promoting fat oxidation and lowering body weight.
How Antioxidants Work
As cells function normally in the body, they produce damaged molecules — called free radicals. These free radicals are highly unstable and steal components from other cellular molecules, such as fat, protein, or DNA, thereby spreading the damage.
This damage continues in a chain reaction, and entire cells soon become damaged and die. This process is called peroxidation. Peroxidation is useful because it helps the body destroy cells that have outlived their usefulness and kills germs and parasites. However, peroxidation, when left unchecked, also destroys or damages healthy cells.
Antioxidants help prevent widespread cellular destruction by willingly donating components to stabilize free radicals. More importantly, antioxidants return to the surface of the cell to stabilize rather than damage other cellular components.
When there are not enough antioxidants to hold peroxidation in check, free radicals begin damaging healthy cells which, can lead to problems.
The Nutritional Value of Tea
In addition to valuable antioxidant properties and contributing to our daily fluid intake target of 2.5 litres, tea contains many vitamins, minerals and amino acids that includes
- Vitamins: C, K, B12, B6 and E
- Minerals: Trace amounts of potassium, manganese, magnesium, calcium
- Amino Acids: Tea is a strong source of amino acids including L-theanine.
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