Dear readers: Green tea has become one of the most widely consumed beverages on the planet, second only to water and its medicinal and health-protective properties have been known to its consumers for many centuries both externally in a paste form to treat rheumatism and internally as a ‘purifying’ soup.
The Emperor Shen Nung, father of Chinese medicine and farming, wrote in his Medical Book that “tea relieves tiredness, strengthens the will, delights the soul and enlivens the sight.”
Shen’s remarks had not been unfounded and modern science proves green tea’s potent medical properties.
Green tea as well as all other teas: black, white, red or dark come from a single Tea plant – Camelia Sinensis, a cultivated bush with evergreen leaves, which grows in hot and humid climates of Asia, Africa and South America. Camelia Sinensis itself originates from China, probably around the border of North Vietnam.
The most important bio-chemical process, which differentiates the tea types, is called ‘fermentation’, a chemical reaction produced by an enzyme contained in the fresh leaf.
Green teas are unfermented teas (unlike black ones for example) – fermentation is avoided/stopped through a process of roasting, which aims to kill the fermentation enzyme in the leaves. The leaves are then rolled and folded by hand to give them their specific look and fired on racks with circulated hot air to reduce the moisture content to 5 – 6 %.
Where does the potential medical value come from?
Green tea has several chemicals, which could provide tea drinkers with health benefits.
It is said that Green tea boosts your energy (probably due to caffeine), prevents heart attack by preventing atherosclerosis, protects against diabetes, fights cancers, prevents Parkinson’s and Alzheimer’s, boosts oral health, improves bone health and density, helps in weight management, lowers cholesterol, protects your skin etc.
These protective chemicals are: Alkaloids, Polyphenols, Vitamins and Minerals, making Green Tea what we call a ‘functional food’ containing no calories but bringing several important components to our bodies to safeguard our health.
I will discuss some of the most important of these chemicals and their health-related effects:
Alkaloids – Caffeine, Theophylline and Theobromine contribute to our alertness and sense of mental and physical invigoration.
To be clear, caffeine in both coffee and tea is one and the same molecule and what’s different, is its concentration – caffeine concentration is higher in coffee. The other difference is that the caffeine from tea is, unlike the caffeine from coffee, released slowly into the body allowing us to stay alert and awake for longer without becoming over-reactive; this makes green tea a perfect companion in any exercise, physical or mental.
Research also links caffeine (but potentially not only this component of green tea) to weight loss.
Caffeine does have a tendency to cause sensitive people some sleeplessness (insomnia-like symptoms) or nervousness and albeit mild, it can be avoided easily by de-caffeinating your green tea – here’s how:
Caffeine is being released in the first few seconds of infusion so use your water prepared for brewing to rinse the leaves for 15-20 seconds (Pour the water over the leaves, infuse it for 15-20 secs and throw that water away. Then pour another water and brew for drinking, minding the right temperature, duration of infusing etc) – this will not change the flavor or alter any other of its aspects but it will shed the tea of most of its caffeine content. You will then be free to enjoy a perfect cup of green tea without being concerned about potential unpleasant caffeine side effects.
Theophylline is found in much smaller concentration than caffeine. Its effects are mild at best but could add to peripheral vasodilatation, which could help in thermoregulation, it relaxes bronchial smooth muscles and assists in breathing although this effect is concentration dependent and tea drinking alone cannot induce it for therapeutic purposes. It also has mild diuretic properties, it positively stimulates the heart etc.
Theobromine is in trace amounts and it adds up to diuretic effects of Theophylline.
These are the most powerful ingredients and possibly those responsible for Green tea’s many alleged beneficial properties.
Polyphenols act as strong antioxidants, which inhibit free radicals’ damaging action on our bodies’ tissues and organs.
The main polyphenolic derivatives of green tea are Catechols and Flavonoids.
These potent antioxidants have an effect on ‘bad’ cholesterol or LDL lowering its concentration in the blood and increasing the levels of HDL or the ‘good’ cholesterol. Combined with its assistance in weight loss and weight management, green tea helps in lowering the two major risks for heart disease and diabetes – High cholesterol and being overweight.
Polyphenols help to prevent arteriosclerosis by having an impact on lowering LDL; also, they are dilators and they improve the flexibility of blood vessels and make them less vulnerable to clogging.
Polyphenols in green tea limit the absorption of fat during digestion so a cup of tea taken within some 40 minutes after meal will help digestion and eliminate fats. Caution should be taken with excessive tea drinking (1.5 liter or more per day) as some polyphenols limit the absorption of Iron and Folates and while a healthy person with a balanced diet should not have such concerns, people with unbalanced diets, with certain medical conditions, pregnant women, vegetarians and similar should limit their consumption of green tea and consult their doctor.
Epigallocatechine 3 Galate
In fighting free radicals responsible for aging of cells, cancer onset and growth, metabolic and other disturbances, one polyphenol grabs the most attention of scientific community – Epigallocatechine Galate or EGCG. This component of green tea is linked to anti-viral properties, it is researched as a molecule inhibiting cancer growth and preventing teeth cavities by killing mouth bacteria. It is believed to be the leader of the army of good chemicals in green tea and one of the strongest fighters against tissue damage.
Green tea has a considerable amount of this bioflavonoid, which enhances the absorption and action of vitamin C. It increases the strength of capillaries, shortens bleeding time and prevents bruising. It also has some antibacterial effect.
B group vitamins
These water soluble vitamins are found in every cup of green tea helping your body’s metabolism and improving your overall health.
Green tea is rich in potassium and fluoride while low in salt, which makes it perfect for a salt-free diet. Fluoride is important in the fight against dental cavities and tea contains approximately 0.3 mg per cup effectively contributing to our daily requirement of around 1mg.
Green tea has also shown promise in preserving bone density in (post)menopausal women reducing their risk for osteoporosis and in reducing the inflammation.
In conclusion, all the evidence seem to suggest that regular drinking of green tea (a few cups a day) will positively affect your health on both physical and mental levels. However, Green tea shouldn’t be consumed as a drug to cure any illness as most of these claims are still under scientific scrutiny and are by no means to be considered therapeutic advice but rather for purposes of prevention and dietary improvements.
People on medical treatments, with anxiety disorders, pregnant women and persons under medical investigations should exercise caution when drinking green or other teas and should consult their doctor before doing so.
In addition, I’d take the real green tea rather than its supplements (I am drinking it in fact, daily, for the last 10 years) as there could be components in the tea, which act together and give such favorable results only in combination and synergy.
Last but not the least, explore the many tea ceremonies and take some time during the day to relax, breathe deeply, clear your mind and brew yourself and your loved ones a cup of this invigorating beverage – health benefits of such a daily oasis could alone prove to be all you need to stay healthy and fit, for a long time to come.
Yours in health,