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Tea and your health

A cup of tea can be stimulating or calming, depending on the brewing time.

How is that possible?

Tea contains 3%-4% caffeine. Different to coffee the caffeine in tea is combined with a group of chemicals called polyphenols. The caffeine does not go into the blood circulation (and so directly to the heart) instead it goes into the nervous system where it stimulates the brain. Unlike coffee this does not generate an Adrenaline rush, it has a more gentle, longer lasting vitalising effect. The longer the tea infuses the less caffeine it contains. The reason for this is the chemical behaviour of the polyphenols. They are slower dissolved in the brewed tea than the caffeine therefore in the first three minutes there is more caffeine in the tea hence the stimulating effect. After three minutes the polyphenols are dissolved, binding the caffeine and the tea has a less stimulating more calming effect.

When referring to “tea”, we are speaking of the plant “camellia sinensis” and its parts. 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.
Tea possesses a wide range of pharmaceutical properties:

•  strengthens immune system
•  powerful germicide
•  combats heart diseases
•  reduces “bad” cholesterol
•  can be 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 litres 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 changed. As a result black tea contains fewer vitamins than green tea but the other substances are still there and so are their valuable properties.

The three main chemical components in tea are : caffeine, essential oils and polyphenols. The oils are responsible for the aroma and most of them are volatile. If tea is stored too long or in an unsuitable way these substances will evaporate and with them the smell and taste of the tea leaf.

Polyphenols are the biggest and most interesting group. Often this group was/is called tannic acid. This is not correct because there is no tannic acid in tea. These names were given before the exact chemical structure of tea was known. Polyphenols are responsible for the colour, for the sometimes astringent taste and above all for the health benefits of tea.

The Caffeine effects

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:

•  it stimulates the central nervous system
•  high level of concentration
•  less reaction time
•  refreshing with increased general alertness
•  stimulates the cardiac muscle without raising blood pressure
•  has a 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 in coffee the caffeine in tea is slower to be absorbed by the human body and stimulates the central nervous system. 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.

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 the polyphenols. The amount of caffeine is always the same in tea but after about three minutes most polyphenols are fully resolved and counterattack 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 and 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 small amounts of caffeine while the green Japanese Gyokuro tea has almost as much as a black Darjeeling tea.

The South American Mate tea is almost as caffeine rich as coffee while the South African Rooibush tea contains no caffeine at all. It is also rich on vitamins which make the Rooibush an ideal tea for children, pregnant women and everybody who should not consume caffeine at all. Please note that decaffeinated tea is not completely caffeine free which is not possible without destroying the tea.

Tea and your heart

Due to a change of life style and eating habits there is an increased risk of heart diseases. Heart attacks are one of the most common causes of death today. “Epidemiological studies suggest that tea consumption is associated with decreased cardiovascular disease” (Boston University School of Medicine, Boston, MA). Besides smoking, high blood pressure and high blood cholesterol are the main threats.

Tea can help to prevent and attack artheriosclerosis in two ways

•  it binds surplus “bad” cholesterol
•  it improves flow of the blood (decreases tendency of blood platelets to clot – 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. It has been proven that Pu-Erh tea is particularly effective against high level of cholesterol.

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.

Tea and Cancer

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 (Mouth, esophagus, stomach cancer, that is the way the tea goes through our body, those parts come in closest contact to the tea).

A study carried out in Japan showed that stomach cancer is at its lowest rate in the Shizuoka prefecture. This is a tea growing area and the people consume more green tea than the average person in Japan. There are studies with similar findings in China.

Cancer is essentially a disorder of cellular genetic material. It can be caused by environmental factors such as radiation, chemical carcinogens and some viruses. A mutation of a healthy cell can be caused by free radicals. They naturally occur in the body during normal cellular processes and can also be formed in response to excess pollution, too much UV sunlight and exposure to cigarette smoke. Our body uses antioxidants which react with free radicals and neutralise them. The best known antioxidants are Vitamin C, E and beta carotine which we eat in fruits, vegetables (vegetable oil) and high fibre cereals.

Tea contains a great amount of powerful antioxidants called flavonoids (sub group of the polyphenols) with anti-carcinogenic properties. Their antioxidant action helps to prevent unwanted mutation of healthy cells into cancer cells. That means that tea is not a cure for cancer but it inhibits the formation or action of cancer causing substances.

One study concluded that at the typical consumption of 3 cups a day tea has approximately the same antioxidant power as eating six apples. Another study found that one or two cups of tea has the same radical scavenging capacity as five portions of fruit and vegetables or 400mg vitamin C equivalents.

Tea as a Germicide

Tea contains substances with a high effectiveness against virus, bacteria and fungi.

The polyphenols possesses anti-biotic properties and work in different ways:

•  they increase white blood cells which fight infections
•  they obstruct the growth of certain virus (e.g. the influenza virus)
•  they fight bacteria especially in the stomach and bowel region
•  they act as a fungicide (for example when tea extract is applied on the outside)
•  In China tea extract in a medicine is successfully used to counteract the loss of white blood cells through radiation therapy.

Green Tea also contains high amounts of vitamin C which is needed to strengthen our immune system.

There is another quite simple protection against germs associated with tea. Because the water, used to make tea, is boiled, it kills most germs. Even with poor water quality it is relatively safe to drink tea especially when traveling.

Teeth

Tea fights tooth decay in two ways. The above mentioned polyphenols reduce the growth of plaque forming bacteria. The bacteria feed on a simple form of sugar and the tea inhibits the conversion from carbohydrate we eat into these forms of sugar.

Tea also contains relatively high amounts of fluoride. It strengthens the tooth enamel which protects the teeth from decay. Two to three cups of tea per day (especially green tea) cover most of the needed fluorine for an adult.

Stomach and Digestion

Most of us have been to Chinese restaurants and were offered Chinese tea after the meal. If you have not tried it yet you should do so the next time. It is usually green Jasmine tea that is served which is not only quite delicate but also helps to digest the food you just ate (and more often too much of it).

It is the substance called Saponine in the tea that breaks down and binds fat and prevents it from getting into the blood circulation. Tea gives relief to the stuffiness you might feel after a meal and soothes the process of digestion.

Because of its alkaline nature, tea is a powerful remedy against high stomach acidity. We all know the unpleasant feeling when the acid gets into our esophagus and causes heartburn (too much meat, “sour” beverages like coffee, cola or lemonades, too much alcohol, eating too fast etc.). A cup of tea helps to restore the right chemical balance in our stomach and as a result gets rid of the heartburn. This is also the reason why tea helps to prevent gastritis. This is an inflammation of the stomach lining caused by high acidity. The alkaline tea relieves the stomach of high acid concentration, relaxes the stomach walls and inhibits the growth of unwanted bacteria. Since gastritis can also be caused by emotional stress, the process of making tea and sitting down to enjoy it can help to relief the stress and find inner balance.

The regulation of the acid level in our body is very important in many respects. Apart from skin and stomach our body should be slightly alkaline to function properly. Gastritis, heartburn, bad breath but also headache, weak immune system and fatigue can be signs for an overly sour organism. Modern eating habits tend to rather sour food like meat, bakery products, nuts and sour beverages (see above). Drinking tea reduces the acid level in our body (stomach, uric acid) and it is also a suitable replacement for the main sinners like coffee and cola.

Longevity and Aging

In China, tea was always an ingredient of immortality potions which claimed to prolong a healthy life.

Health benefits derived from tea like the reduced risk of heart disease or a stronger immune system contribute to longevity. Aging is the accumulation of damaged body cells which do not function properly anymore. This damage is caused by free radicals. Antioxidants bind those free radicals and neutralise them. Potent antioxidants like vitamins and polyphenols are abundant in tea and can slow down the process of aging.

There are many other factors that determine the aging process but by stimulating vital body functions tea can help us to live a longer and healthier life.

Slimming effects

It sounds almost too good to be true but tea is an ideal part of every diet or fasting cure. Tea does not contain any calories or any fat. Instead it binds fat and prevents it from getting into the bloodstream. As a result it can help to reduce the fat in the tissues.

By drinking tea, especially green tea, the body is supplied with much needed vitamins (C, thiamin) and minerals (e.g. fluorine, potassium). Tea also suppresses the hunger feeling and reduces the appetite for heavy or sweet food which often is the cause for overweight.

When changing eating habits or on a fasting cure our digestion gets upset which can result in nausea, heartburn and fatigue. Besides the right food mix, tea is the ideal drink to go with it. It settles the stomach and the intestinal tract and reduces surplus acid. It helps body and mind to relax and is gentle but effective against tiredness and fatigue. The caffeine responsible for this, functions also as a diuretic. This helps to flush and detox the body.

That does not mean that drinking only tea will get you the ideal weight. Tea can only be part of a change of food and habits in order to lose weight.

Pu-Erh and Oolong teas are especially renown for their slimming effects.

Free radicals

These are key in the development of degenerative conditions such as heart disease, cancer, and stroke. Antioxidants are compounds that locate harmful free radical molecules in the body and detoxify them, reduce their production, and remove key elements necessary for their performance.

Polyphenols, a category of antioxidants found in tea and represented most commonly as flavonoids, constitute up to 15% of dry leaf weight. Though flavonoids appear in equal amounts in both green and black teas, they are manifest differently in each. Their counts can be ten-fold that found in fruits and vegetables. Although some findings are conflictive, the majority of current research indicates that antioxidants introduced into the body by drinking tea are beneficial and bolster the body against ailments common to ageing.

Though an incredibly healthy beverage, tea is often disingenuously touted as a wonder cure-all for many of the maladies which plague humankind. It is not. Nevertheless, below we present an account of some current research and its findings, all of which indicate that drinking tea is healthy and does show

Alzheimer

Though tea-drinking nations do not show lower incidences of Alzheimer’s disease, a British study indicates that black and green teas interfere with or stop the actions of three chemicals associated with the disease. The first chemical, acetyl cholinesterase, is known to cause a breakdown in components which move and process information in the brain. The other two, butyl cholinesterase and beta-secretase, are key in the formation of tangles of protein found in the brains of Alzheimer’s victims. Green tea inhibits actions of acetyl cholinesterase, butyryl cholinesterase, and betasecretase, while black tea stops only the second two chemicals.

Caffeine

Tea contains caffeine. And despite what one may hear, it is chemically identical to the caffeine found in coffee. On average, however, tea contains less caffeine than coffee, with properly brewed green tea yielding less caffeine than black varieties. The general consensus is that 5 to 6 cups of tea during a day is a healthy amount and can be counted as part of the daily hydration regimen.

Cancer

There is a mass of information available regarding tea and cancer prevention. For reasons of brevity, we include only highlights here:

•  Drinking four or more cups per day may reduce cell damage in smokers.
•  In tea-drinking men, prostate cancer growth may be inhibited.
•  Tea polyphenols have been shown to kill breast cancer cells.
•  Cancer risk in the urinary & digestive tracts, mouth, and esophagus is apparently greatly reduced by consuming especially green tea.

Heart health

Drinking tea may reduce risk of hypertension, which can lead to stroke, heart attack, and kidney dysfunction. Apparently, one of tea’s healthful benefits is an improvement in the functioning of endothelial cells, which are the cells that line blood vessels and regulate blood flow. Restricted functioning of these cells can lead to hardening of the arteries. In those who drink tea regularly, measured benefits are of sustained duration, while short-term drinkers experience benefits up to two hours after drinking tea. In a Japanese study, an increase in HDL (“good”) cholesterol counts has been noted in tea drinkers, while LDL (“bad”) cholesterol demonstrated a reduction in count.

Tea Bones

A British study found that, in post menopausal women who regularly drink tea, bone mineral density was significantly increased in the spine and hip areas in comparison with those who did not drink the beverage. The mechanism is not fully understood, but it may be attributed to a resemblance between some of tea’s components and estrogen. It was also noted in the research that women who took milk with their tea saw a further increase in benefits. Though some studies indicate caffeine in general may negatively impact bone density, its presence in tea apparently does not produce the same results. in count.

Finally…

Though evidence has not been conclusive, in conjunction with proper eating habits and exercise, tea can have a positive impact on the body in general.

As a precaution, those with the below conditions may want to speak with their physician before consuming more than moderate amounts of tea:

•  heart problems or high blood pressure,
•  kidney disease,
•  an overactive thyroid (hyperthyroidism)
•  an anxiety or nervous disorder, or
•  a bleeding or blood-clotting disorder, or if you take blood-thinning medication

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