Tea & Health

The earliest information we have about the use of tea leaves is for medical purposes.

The list of pharmaceutical properties of tea is long:

  • strengthens immune system
  • powerful germicide
  • combats heart diseases
  • reduces ‘bad’ cholesterol
  • has anti-carcinogenic properties
  • improves oral health
  • is an effective digestive
  • stimulates central nervous system
  • is a smooth muscle relaxant
  • influences aging process and improves longevity
  • can be used as slimming diet
  • not to forget: makes one feel good.

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.

These are  the main chemical components in tea:

  • Polyphenols
  • Amino Acids (give tea its satisfying flavour or umami taste, especially shaded Japanese teas like our Gyokuru Hikari)
  • Enzymes (responsible for oxidisation)
  • Pigments (responsible for absorbing light for photosynthesis and to give the leaves their colour)
  • Carbohydrates (use to store the plants energy and to create polyphenols)
  • Methylxanthines (includes caffeine and two other similar important compounds: theobromine and theophylline)
  • Minerals (tea contains 28 mineral elements like manganese, arsenic, nickel, selenium, iodine, aluminium, potassium and high amounts of fluorine)
  • Volatiles (hundreds of volatile substances are largely responsible for the flavour and aroma of tea)

Polyphenols are the biggest and in health terms the most interesting group. They are responsible for the sometimes astringent taste and above all for the health benefits of tea.  

There are an estimated 30,000 polyphenolic compounds in tea. The most important group are flavonoids, with flavanols as the most prevalent. Flavanols (sometimes also referred to as tannins) are converted during oxidation to theaflavins and thearubigins—the compounds responsible for the dark colour and robust flavours in black teas. The major flavanols in tea are: catechin (C), epicatechin (EC), epicatechin gallate (ECG), gallocatechin (GC), epigallocatechin (EGC), and epigallocatechin gallate (EGCG). EGCG is the most active of these catechins and is often the subject of studies regarding tea antioxidants.

The Caffeine effects

Zen monks discovered 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 3%-5% caffeine. There is more caffeine in the tips and the first two leaves than in the other parts of the plant. 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 absorbed by the human body and stimulates the central nervous system. This results in an increased brain activity, one feels concentrated and focused without the increased muscle activity one gets after coffee consumption.

Black tea contains the highest amount of caffeine followed by Oolong, green, white and Pu Erh. There are some exceptions to the rule. Since most of the caffeine and health benefits sit in the bud and the first two leaves of the plant other teas of high quality, for instance our White Bud, can contain almost as much caffeine than a black tea.

Tea and your heart

Due to a change of lifestyle 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 risk …” (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 arteriosclerosis in two ways:

  • it binds surplus ‘bad’ cholesterol (especially Oolong and Pu Erh, check out our Cholesterol reducing Wellness tea at www.houseoftea.ie)
  • 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 delicious way to keep your heart in shape.

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, oesophagus, stomach cancer – that is the way the tea goes through our body – those part come in closest contact to the tea).

The earlier mentioned catechins contain a great amount of powerful antioxidants with anti-carcinogenic properties. Antioxidant neutralise free radicals which can cause unwanted mutation of healthy cells into cancer cells. This means that the catechins in tea are not a cure for cancer but may inhibit 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 (green) tea has the same ‘radical scavenging capacity’ as five portions of fruit and vegetables or 400 mg vitamin C equivalents.

Tea as a Germicide

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

The polyphenols possess antibiotic 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. 


The mentioned polyphenols reduce the growth of plaque forming bacteria. They feed on a simple form of sugar and the tea inhibits the conversion from carbohydrate we eat into these forms of sugar (side effect is fresh breath). Tea also contains high amounts of fluorine. It strengthens the tooth enamel which protects the teeth from decay. Green tea reduces the acidity of saliva and accumulation of dental plaque, responsible for cavities. Two to three cups of green tea per day 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. It is usually green Jasmine tea that is served which is not only quite delicious but also helps to digest the food you just ate. 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 provides relief to the stuffiness you might feel after a meal and soothes the process of digestion (herbs like peppermint and fennel have a similar relieving effect). 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 oesophagus and causes heartburn (too much meat, ‘sour’ beverages like coffee, cola or lemonades, too much alcohol, eating too fast etc.). 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. The alkaline tea relieves the stomach of high acid concentration, relaxes the stomach walls and inhibits the growth of unwanted bacteria. 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. 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.

Slimming effects

Tea is an ideal companion for 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.

This applies particularly to Pu Erh tea. It works in two ways:

First it suppresses the hunger feeling and reduces the appetite for heavy or sweet food which often is the cause for overweight.
Secondly Pu Erh stimulates the liver metabolism which controls the accumulation of fat in the body.

When changing eating habits or when 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 an diuretic. This helps to flush and detoxify the body.

Hangover cure

Tea, especially Pu Erh reduces the hangover symptoms in various ways.

It re-hydrates the body.
It stimulates the liver which is responsible to break down the alcohol in our blood (clinical trials have shown that the intake of Pu Erh can reduce the breakdown time by almost half).
It provides a gentle caffeine kick to get on with life.

Based on those qualities we have a special Hangover tea designed, see Wellness section at www.houseoftea.ie.

Contact Information


House of Tea, 7 Ardee Court, Ardee Street, Bray, Co. Wicklow, Ireland.


+353 1 2899436


The House of Tea was founded in Dublin in 2004 by Martin Mehner. It was the lack of good leaf tea that motivated us to set up a company that does exactly that.

Our main goal is to introduce people to the diverse world of tea and to show them that there is much more to tea than just a bag. We are dedicated to providing quality teas from around the world. Most teas are sourced directly from the tea gardens or the manufacturers. This allows us to monitor the quality of our products and to ensure that the workers in the mainly Asian countries are paid fairly.


Image Gallery