The mighty cup of tea is something that has been enjoyed across cultures for many years. In China tea has been used as a medicine to promote a healthy mind and body for about 5000 years. In Japan, in the fifteenth century, this medicine grew into a beverage. Tea developed as a way of life—a path of practice in search of spiritual fulfilment.
The tea ceremony, or Chanoyu, was based on the notion that we can never attain inner peace without a deliberate effort to free ourselves from the cares and worries of the world. Chanoyu was a means to step beyond the daily attachments and go inward.
Tea was introduced to the Western world in the early seventeenth century. The afternoon tea party, with the delicate clatter of trays and saucers and the soft rustle of feminine hospitality, has played an important function in Western society since then. In more recent years, there has been a resurgence of interest in tea, with many more teahouses popping up, and many more varieties of teas to choose from. There is no denying that this brown beverage, plucked from the East, plays an important role in our daily lives.
Drinking tea not only provides a flavourful taste experience and a means of relaxation, but also helps to promote good health. Today, scientific research has confirmed what those in the East believed for many years—that the mighty tealeaf does have wide-ranging health benefits.
Types of tea
‘Tea’ technically only comes from the camellia sinensis plant, and includes green tea, black tea, oolong tea, and white tea. ‘Herbal tea’ is actually a ‘tisane’—an infusion made from anything other than the leaves of the tea plant. Tisanes can be made with fresh or dried flowers, leaves, seeds, fruits, and roots. Tea and tisanes are generally made by pouring boiling water (or near-to-boiling water for green and white tea) over the plant parts, letting them steep for a few minutes, straining, and serving.
While all teas come from the one camellia sinensis plant, they all exhibit different qualities that have been determined by the way the tealeaves have been processed. The tea-making process may involve full oxidation of the tealeaf, partial oxidation, or no oxidation before it is dried, and it is this that will determine the colour, flavour, and characteristics of the tea.
White tea is derived from the young new leaves from the tea plant in early spring. They are young leaves that contain no chlorophyll and still have silvery-white ‘hairs’ indicating new growth—hence the name ‘white’ tea. The tightly-rolled buds of the white tea are immediately fired or steamed after letting them wither (air-dry) for a period of time, so that they do not go through any oxidation.
The processing of green tea is similar to white tea in that it does not go through any oxidation. After the leaves are plucked, they are sometimes laid out to dry. Then in order to neutralise the enzymes thus preventing oxidation, the leaves are steamed or pan-fried. Next the leaves are rolled up in various ways and tightness before further drying takes place.
The processing of black tea requires full oxidation of the leaves. After the leaves are plucked, they are laid out to dry for up to 24 hours. The leaves are then rolled to crack the surface, so that oxygen will react with the enzymes inside and begin the oxidation process. The leaves are left to completely oxidise, thus turning them to a deep black colour.
The processing of oolong tea is the most difficult, as it is partially oxidised—somewhere in between the amount done for green and black tea. After the leaves are plucked, they are laid out to dry for up to 24 hours. The leaves are then vigorously tossed about in baskets, in order to bruise the edges of the leaves. This bruising causes the leaves to only partially oxidise because only a portion of the enzymes are exposed to air. The leaves are then steamed in order to neutralise the enzymes and stop any further oxidation before full drying takes place.
Health benefits of tea
In 1211, the Japanese monk Eisai wrote: ‘Tea is a miraculous medicine for the maintenance of health. Tea has an extraordinary power to prolong life. Anywhere a person cultivates tea, long life will follow. In ancient and modern times, tea is the elixir that creates the mountain dwelling immortal.’
Back then, it was believed that its taste and stimulative properties were useful for treating tumours, abscesses, bladder ailments, and lethargy, among other conditions. The potential health benefits of tea consumption have been supported by numerous scientific studies in more recent years, and whilst the vast majority of these studies have been of green tea, some studies have been made of the other types of tea derived from the camellia sinsensis plant, such as white, oolong and black tea. Some potential health benefits of drinking tea are discussed below.
Tea contains an abundant source of natural plant-derived antioxidant compounds called polyphenols. In this broad polyphenol class of antioxidants are flavonoids and catechins, which can provide protective antioxidant action against harmful free radicals that can damage DNA, cell membranes, and other cell components. While most fruits and vegetables contain natural antioxidants that help combat free radicals, it is the tealeaf that boasts one of the highest total flavonoid contents of all plants—at 15 per cent of its dry weight. Green and white tea are believed to have higher antioxidant levels than both oolong and black tea, due to their differing manufacturing processes.
The tealeaf contains vitamins C, K, B12, B6, and E and trace amounts of calcium, magnesium, manganese, and potassium.
Boosting immune system
Tea contains the amino acid L-theanine, that has been found to strengthen the immune system in two studies conducted by Harvard University and the Brigham and Women’s Hospital. Tea consumption was found to lead to an increase in the number of T-cells to help the body fight infection.
Many studies have indicated that green tea may help protect against a range of cancers (including prostate, lung, and breast cancer) as well as heart disease—largely due to tea’s high antioxidant protection. Recent research shows that the catechins in tea inactivate oxidants before cell damage occurs, reduce the number and size of tumours, and inhibits the growth of cancer cells.
Preventing heart disease
Since free radicals are a major cause of heart disease, tea that contains antioxidants may help to inhibit or reduce the risk of heart attack and stroke. Furthermore, many studies have also shown that both green tea and black tea help to lower blood cholesterol levels and lower blood platelet activation, which is linked to blood clotting that increases the risk of heart attack.
The flavonoids found in tea may also improve the integrity of the blood vessels, thereby increasing coronary blood flow.
Increasing mental alertness and reducing anxiety and stress
L-theanine has been known to have a profound effect on the nervous system. Theanine is absorbed by the small intestine and crosses the blood–brain barrier where it influences the ‘feel-good’ neurotransmitters of the brain (serotonin and dopamine). This, in turn, increases the alpha brain-wave activity and has the effect of producing a calmer, yet more alert, state of mind.
Furthermore, tea drinkers have been found in a UCLA study to have lower stress hormone (cortisol) levels.
Clinical trials conducted by the University of Geneva and the University of Birmingham indicate that green tea raises metabolic rates, speeds up fat oxidation, and improves insulin sensitivity and glucose tolerance. In addition to caffeine, green tea contains catechins that raise thermogenesis (the rate at which calories are burned) and hence increases energy expenditure. Tea catechins may also increase exercise endurance by improving fat metabolism.
Adding milk to tea
There are wide and varied health benefits from drinking tea, whether it be black tea, green, white, or oolong. However, what happens to tea when we add milk? Traditionally, in the East, green tea was always consumed without milk. It was only in the early seventeenth century when tea (mostly black tea) was introduced to Europe that cream, milk, and sugar were considered to be a tasty addition to this wonderful beverage.
These additives have various obvious impacts on our health: too much sugar can lead to blood sugar fluctuations (and diabetes), weight gain, and lowered immune system function, while too much saturated fat (contained in milk and cream) can cause other problems.
Research has also found that some of the health benefits of drinking tea, discussed above, are eliminated when milk is added. One study conducted by Berlin University showed that adding milk to tea will block the effects of tea in protecting against cardiovascular disease because the casein in the milk binds to the catechins in the tea, inactivating them. Other studies have shown milk has little or no deleterious effects on the observed increase in total plasma antioxidant activity. There is probably not enough evidence to conclude that adding milk to tea does actually reduce the potential health benefits.
Herbal teas (tisanes)
Herbal teas or tisanes exhibit wide and varied health benefits that are distinct to those attributed to tea. Some commonly-known tisanes are peppermint, which is both cooling and invigorating, and chamomile, which is soothing and calming. We can make tisanes from a wide array of herbs, all of which can be used for their various effects or to help treat various conditions. By infusing the herbs in boiling water, we can extract the active constituents that will have the desired effect on the body. A tisane is simply an herbal medicine that is very safe and effective and in a form that we can actually enjoy (as opposed to a herbal tablet or tincture).
Quality of tea and tisanes
The quality of tea and tisanes can vary, depending on the climate, location, and type of processing that the ingredients have been through. Tealeaves are separated into the following grades: ‘whole leaf’, ‘broken leaf’, ‘fannings’, and ‘dust’. The tea’s taste, body, and health properties will vary depending on the leaf size. Dust is the smallest grade of tea and is used in mass-marketed teabags. Drinking whole leaf tea and tisanes allows you to experience a wider range of complex flavours. Being larger in size, there is less exposure to air, light, and heat, which age or oxidise the herb or tea, making it more beneficial to our health, compared to its smaller-sized counterpart.
Whether you choose tea or tisanes as your preferred brew, I can assure that you will benefit from the wide-ranging health benefits that these wonderful plants can offer us.
Enjoy your brew!
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Herb Palace, History of Herbal Medicine,
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BBC News, ‘Tea, a Healthier drink than Water?’, www.news.bbc.co.uk, 2006.
Davis, Jeanie, ‘The Health Benefits of Tea’,
Nothing But Tea, ‘Health Benefits of Tea’,
Imperial Tea Garden, ‘Health Benefits of Tea’, www.imperialteagarden.com, 2003
Better Health, ‘Tea Leaves and Health’,
Tea Association of Canada, ‘Tea—A Healthy Beverage Choice’, www.tea.ca, 2006
Published in Kindred, Issue 27, Sept ’08