Why Is Tea Healthy ?
Research has shown that tea, as well as fruits and vegetables, contains powerful antioxidants called flavonoids. Scientific evidence increasingly suggests that the flavonoids found in tea, as well at those found in fruits and vegetables, form an important part of a healthy diet.
Antioxidants are substances found in some food and drinks that can help to inhibit the oxidation reactions caused by free radicals. Well known examples of antioxidants are vitamins A, C and E.
So as long as your drink is 'real' tea, then whether you take it with or without milk or sugar, or even decaffeinated, you will still benefit from the antioxidant activity of the flavonoids.
Tea is a natural drink. All 'real' tea comes from Camellia sinensis and contains a high level of flavonoids.
Tea is available in a number of different forms including decaffeinated tea, flavoured tea and speciality teas. Provided that the major constituent of these products is real tea (Camellia sinensis) then they will all show high antioxidant activity.
Many infusions are not real tea. They are often made from different plants and so will not have the same benefits as tea.
During tea manufacture the leaves are fermented to different degrees.
Black tea is the most popular type of tea. It is produced from the top two leaves and a bud of the plant Camellia sinensis. It undergoes no technological manufacturing process. It is left to wither naturally after the leaves have been plucked. After withering the leaves are broken to release the natural juices and left to ferment or oxidise naturally. It is then dried, sorted and packed into chests. There are no additives, flavourings, colourings or preservatives. Black tea is fully fermented, and the 'black' refers to the colour of the tea leaves, which turn a rich, coppery brown after the fermentation and drying process. The actual character of the final blend will depend on how the tea is grown, and the soil, climate and altitude will all affect the taste of the final blend.
Oolong is partially fermented tea. The leaves are fermented for only a short time and the flavour of oolong tea remains quite delicate.
Green tea is non-fermented, and produces a clear, aromatic, delicately flavoured tea, traditionally popular in China and Japan.
Although fermentation modifies the flavonoids, the total level of flavonoids and their overall antioxidant power is similar in all teas.
Tannin
Tea contains polyphenols, erroneously called tannin by the tea trade. These are responsible for the pungency of tea and give it its taste. However polyphenols should not be confused with tannin as obtained from tree bark.
Antioxidants are substances found in some food and drinks that can help to inhibit the oxidation reactions caused by free radicals. Well known examples of antioxidants are vitamins A, C and E.
Environmental factors such as sunlight, smoking and pollution can lead to increased levels of free radicals in the body.
Tea is also a good source of antioxidants. The antioxidant levels in tea are higher than in many fruits and vegetables.
Fruits and vegetables should always form part of a healthy diet. However, emerging scientific evidence suggests that tea is also a valuable part of a healthy diet, and contributes substantially to our antioxidant intake.
Tea contains caffeine. Over 200 scientific papers a year are published on caffeine and there is now general consensus that caffeine has no deleterious effects on the heart, blood cholesterol or the circulation, and there is no evidence that it gives rise to cancers. The U.S. Food and Drug Administration (FDA) has given caffeine "GRAS" status, ie. Generally Recognised As Safe. According to the UK Food Standards Agency, 300 mg (equivalent to 6 cups of tea) is quoted as an acceptable moderate daily intake.
The typical caffeine content of beverages in the UK are as follows:
• Average cup of instant coffee - 75 mg
• Average mug of coffee – 100 mg
• Average cup of brewed coffee – 100 mg
• Average cup of tea – 50 mg
• Regular cola drink – up to 40 mg
• Regular energy drink – up to 80 mg
• Plain bar of chocolate – up to 50 mg. Caffeine in milk chocolate is about
half that of plain chocolate
Source: UK Food Standards Agency
Caffeine stimulates the central nervous system and respiration. It
influences the metabolic processes of all body cells.
The average cup of tea contains approximately 50 milligrams of caffeine,
which is half the amount contained in an average cup of coffee. When tea is
drunk, the caffeine is absorbed gradually into the body. The body will only
absorb its natural requirements, so that the rest of the caffeine will be
washed out of the system. The comforting quality of the warm tea is felt at
once, whereas the gradual absorption of the required amount of caffeine
giving that 'uplift' or stimulus to the mind and body, is slower and less
perceptible but is there just the same.