Sanitary engineering, 1.letnik CAMELLIA SINENSIS TEA

Valentina Rutar Polanec Ljubljana, 29.05.2013Today I would like to share some things I have learned about Camellia sinensis, thespeciesofplantwhich is used to produce the popular beveragetea. The nameCamelliais taken from theLatinized nameof Georg Kamel(16611706), a Czech-bornJesuitlay brother, a pharmacist, and missionary to thePhilippines.

Carl Linnaeuschose his name in 1753 for the genus to honour Kamel's contributions to botany.

And the word sinensis literally means from China. There are several types of tea known to the world, but the existence of the following three is the most common;

-Green tea

-Oolong tea

-Black tea

Picture: (Tea of different fermentation prepared, in cups: green tea, yellow tea, oolong tea, and black tea)The difference between them is that Green tea leaves are not fermented, they are withered and steamed.

Whereas Black tea and oolong tea leaves undergo a crushing and fermenting process.

I am sure that you have already heard about tea being a healthier substitute for coffee.

But I believe that you do not know why.

And this is the question that also bothered me for quite a while, since I have started being a regular tea consumer.

Camellia sinensis originates from China, but nowadays it is mostly cultivated in India, Taiwan, Japan, Shri Lanka, south-east Asia, a little less in Africa and of course in China.

The leaves have been used for medical purposes for centuries, as they were believed totreatasthma,angina pectoris, to fightcancerandheart diseases, due to the fact that drinking tea lowers LDL- the bad cholesterol, it burns fat and consequently effects on weight loss.

Moreover, tea may keep you look young, as it delays cell aging process, it prevents diabetesandstrokes, it blocks UV radiation-induced skin damage, it softens allergic responses, it boosts sexual performance and staves offdementia.

Some scientific studies also showed that Camellia sinesis is capable to inactivate viruses such as herpes simplex 1 (oral) and 2 (genital).Be that as it may, the list of teas advantages goes on and on

After knowing all these health benefits of the tea, another question occurred to me. What sorcery makes this plant so healthy in so many different ways?

The answer is hidden in these small molecules called catechins, in which epigallocatechin-3-gallate (EGCG) is the most abundant. Its a type of antioxidant called flavonoid or polyphenols.(But this was the point when I realised that I have focused on too many details, so I decided to illustrate it to you on a more general way.) An apple slice turns brown. Fish becomes rancid. A cut on your skin is raw and inflamed.

All of these result from a natural process called oxidation.

It happens to all dying cells in nature, including the ones in your body.

While the body metabolizes oxygen very efficiently, 1 or 2 % of cells will get damaged in the process and turn into free radicals.

"Free radicals" is a term often used to describe injured cells with damaged DNA, which creates the seed for disease.

When a cell's DNA changes, the cell becomes mutated. It grows and reproduces abnormally and quickly.

They are "free" because they are missing a critical electron, causing them to rob and pair with another molecule.

In addition to this, they do not just damage one molecule, since one free radical can set off a whole chain reaction. To illustrate, when a free radical oxidizes a fatty acid, it changes that fatty acid into a free radical, which then damages another fatty acid and so on. (And this is the reason why and how we get cancer)But the sad truth about all mentioned is that the radicals created in our bodies are not the only ones, since external toxins, especially cigarette smoke, air pollution, alcohol, UV-radiation, pesticides and other toxins, are the free radical generators.

However, what antioxidants do is, they scavenge for cell-damaging free radicals, they detoxify and pair with them.

When your body needs to put up its best defence, especially in today's polluted environment, antioxidants provided by our own body such as uric acid, folic acid, carotenes, coenzymes, melatonin are crucial to your health.

In order to help your body protect itself, Mother Nature provides thousands of different antioxidants, such as vitamins and minerals in various amounts in fruits, vegetables, whole grains, nuts, and legumes.

Now that you know how antioxidants and radical work, let me return to this wonderful plant Camellia sinensis.What is interesting about tea is that its substance contains ten times more antioxidants as any fruit and vegetables do. One of them isamino acidL-theaninewhich modulatescaffeine's psychoactive effect on the heart, nervous system and kidneys as diuretic.

It also contributes tea'spleasant taste.

Furthermore, tea also contains tannin (flavonoids) which causes this dry, harry taste in the mouth following the consumption of unripened fruit (let me remind you of a persimmon fruit) or red wine (dry taste of Cabernet sauvignon).

However, tea may have some negative impacts on health, such as over-consumption ofcaffeine, and the presence offluoride,aluminiumandoxalates (COO)22 , due to the tea plant's high sensitivity to and absorption of environmental pollutants.

To sum up, even though I have stated some teas negative impacts on health, the amount of its consumption (fluoride,aluminiumandoxalates (COO)22 ), to leave bad consequences would have to be enormous.

In preventive, Tea is basically one of the most efficient home medicines to be available anywhere in the world and affordable for anyone.Sure, you can live your whole life without getting epicatechin-3-gallate, a flavonoid found in huge quantities in green tea. But if having it in your diet promotes better health, why not try it?PAGE 4