8. Tea and Health

1. What is Tea?
2.The Tea plant
3. History of Tea
4. Tea sorts and their Production
5. Tea grades
6. Tea regions
7. How to brew a perfect cup of tea

The earliest information we have about the use of tea leaves is for medical purposes. Centuries before tea started to become a popular beverage in China it was used as a medicine against head ache, weariness, rheumatism, to improve eyesight and various other things.
Why would the Chinese have used tea (and still using it) for such a long period of time if there were not any benefiting effects?
Because tea posses a wide range of pharmaceutical properties:
- strengthens immune system
- powerful germicide
- combats heart diseases
- reduces "bad" cholesterol
- is an anti-carcinogenic
- improves oral health
- is an effective digestive
- stimulates central nervous system (= better concentration, less reaction time etc.)
- is a smooth muscle relaxant
- influences aging process and improves longevity
- can be used as slimming diet

Until today not all of the above effects can be explained conclusively. Due to the very complex chemical nature of tea the different circumstances and conditions when tea is drunken, by whom and in what quantities, it is difficult to establish an unambiguous and sound proof. One big myth about tea is that you have to drink gallons to derive any health benefits. That is not the case. Intakes of only three to five cups of tea a day have been associated with health benefits. A second myth goes that only green tea possesses all of the important substances while black tea is nice to drink but quite useless. Not quite true either. Due to the oxidation (also called fermentation) of black tea some chemical compounds are being altered (e.g. the very important flavonoids). As a result black tea contains less vitamins than green tea but the other substances are still there and so are their valuable properties.

Monks discovered 2000 years ago that the use of tea helped them through their exhausting hours of meditation. It is the caffeine in tea that is responsible for these effects:
- stimulant of central nervous system (high level of concentration, less reaction time, refreshing with increased general alertness)
- stimulates the cardiac muscle without raising blood pressure
- has diuretic effect
- stimulates the respiratory system
- delays fatigue

Tea leaves contain about 5% caffeine (it was called theine first but it is chemically exactly the same). There is more caffeine in the tips and the first two leaves than in the other parts of the plant (therefore some of the best Darjeeling teas are quite rich in caffeine). Smaller tea grades (like "Dust" and "Fanning" in tea bags) release more caffeine quicker than the intact leaf. Unlike coffee the caffeine in tea is slower to be absorbed by the human body and stimulates the central nervous system (for the reason see 2.1 Caffeine). This results in an increased brain activity after about 30 mins and lasts between 1,5 - 3 hours to go back to zero. Caffeine in coffee is absorbed quickly into the blood circulation, stimulates the heart (increased heart beat and blood pressure) and lasts for 30-60 mins. After the stimulation wears off the body is more exhausted than before the intake of coffee. The following graph shows the different effects of caffeine in tea and coffee:

A unique feature of tea is the possibility to regulate the effects of caffeine to a certain degree through the brewing time: 1-3 mins more stimulating 3-5mins less stimulating, relaxing at the same time This is possible because of the chemical partnership between caffeine and tannic acid (for more details see 2.1 Caffeine). The amount of caffeine is always the same in tea but after about three minutes the tannic acid is fully resolved and counterattacks the stimulating effect of the caffeine. That means the concentration level is still high but the muscle activity is low which creates the unique feeling of being mentally alert without being "jumpy". Despite the gentle way the caffeine in tea effects the human body it is not suitable or only in small quantities for people with heart diseases, pregnant women or it can prevent sleep when taken to late in the day. If you do not want to renounce tea completely there are types with less caffeine or even none. As a rule the longer the fermentation of the tea takes the higher the caffeine content. That means that green tea posses less the than half fermented Oolong which again contains less than black tea. There are some exceptions, for example the black Chinese Keemun tea contains only a small portion of caffeine while the green Japanese Gyokuro tea has almost as much as a black Darjeeling tea. The following graph shows the approximate amount of caffeine in the different tea sorts and a comparison to other caffeine containing substances:

Besides smoking high blood pressure and high blood cholesterol are the main threats. Both diseases are connected to each other: high blood pressure can damage the blood vessels, especially the artery walls. To prevent the damaged blood vessel walls from peeling, low-density (LDL, so-called "bad" ) cholesterol coats and covers up the abrasions and protects the underlying tissue like a waterproof bandage until the tissue heals. "Bad" cholesterol is actually good and vital for our body and it is only the excess of it in our blood that can clot the blood vessels and causeartheriosclerosis . On the other side a high blood level of low density cholesterol can also lead to artheriosclerosis which results in high blood pressure and a higher risk of a heart attack. Tea can help to prevent and attack artheriosclerosis in two ways:
1. it binds surplus "bad" cholesterol
2. it improves flow of the blood (decreases tendency of blood platelets to clot which prevents high blood pressure)
By helping to prevent the cause for heart diseases tea is an affordable, natural and, if properly done, delicious way to keep your heart in shape. However it cannot replace necessary medication and one will only benefit from it through regular use. Besides the described physical effects there is also a psychological side of drinking tea. A cup of tea can help to relax, can help to reduce stress, can help to lower the blood pressure by just sitting back, unwind and find inner rest. A break, even if it is only for a few minutes, can bring your body back to normal and refresh your mind.

A lot of research, studies and clinical trials are being conducted to reveal the role of tea drinking in preventing cancer. In most cases researchers could establish a connection between the consumption of tea and the outbreak of cancer. It is not quite clear yet to what extend tea can fight cancer. It also seems that tea inhibits some types of cancer better than others. Tea helps to prevent cancer or slows down the development of cancer cells.
A study carried out in Japan showed that stomach cancer is at its lowest rate in the Shizuoka prefecture. This is an tea growing area and the people consume more green tea than the average person in Japan. There are similar studies with similar findings in China.
That led the scientists to the conclusion that drinking tea is an important factor in the prevention of cancer. What tea does not do is to cure cancer!

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