Green tea contains antioxidants properties, polyphenols, theanine and etc which are very good towards us. So there's simply no reason to stay away from green tea.

Polyphenols - Polyphenols are a class of phytochemicals found in high concentrations in green tea, and have been associated with heart disease and cancer prevention. It seems to help keep cancer cells from gaining a foothold in the body, by discouraging their growth and then squelching the creation of new blood vessels that tumors need to thrive. Study after study has found that people who regularly drink green tea reduce their risk of breast, stomach, esophagus, colon, and/or prostate cancer. Polyphenols also helps to keep blood vessels from contracting and raising blood pressure.
The slight astringent, bitter taste of green tea is attributed to polyphenols.

Tannins - A group of simple and complex phenol, polyphenol, and flavonoid compounds. Produced by plants, all of the tannins are relatively resistant to digestion or fermentation. All tannins act as astringents, shrinking tissues and contracting structural proteins in the skin and mucosa.

Catechins - Catechins are a category of polyphenols. In green tea, catechins are present in significant quantities, more specifically; epicatechin (EC), epigallocatechin (EGC), epicatechin gallate (ECG) and epigallocatechin gallate (EGCG). EGCG makes up about 10-50% of the total catechin content and appears to be the most powerful of the catechins ?with antioxidant activity about 25-100 times more potent than vitamins C and E. A cup of green tea may provide 10-40mg of polyphenols and has antioxidant activity greater than a serving of broccoli, spinach, carrots or strawberries.

Flavonoids - Flavonoids are plant pigments, and are the brightly colored chemical constituents found in most fresh fruits and vegetables. They may aid in protecting against infection. Deficiency can result in a tendency to bruise easily.

Theanine - An amino acid that produces tranquilizing effects in the brain, theanine is a unique amino acid found in the leaves sencha. Getting-up-there adults who drink at least two cups a day are half as likely to develop cognitive problems as those who drink less. Why? It appears that the tea's big dose of antioxidants fights the free-radical damage to brain nerves seen in Alzheimer's and Parkinson's.

Not only green tea helps to keep your healthy but is also good for your skin and watching your body weight.
Yes! Turns out that green tea speeds up your body's calorie-burning process. So indirectly it helps you to loose some weight but do not expect it to work magically. Exercising and mainting a good diet plan is still needed. As for your skins, more skin care products are including green tea as one of their ingredients. It seems that green tea helps to block skin cancer. Also I have read about using left over green tea leaves to sooth your itching and swelling on your skin. Finally, with the rich antioxidant properties sure to keep your skin looking radiant all the time.

What about caffeine in the green tea? The truth is green tea contains the less caffeine compared to black tea, oolong tea of coffee. According to Teacuppa.com tea library, a cup of Green tea (6 oz) contains 8 to 36 mg of caffeine. Caffeine in moderation can actually be good for you. It stimulates the nervous system and promotes blood circulation. It also works as a digestive after a heavy or greasy meal. Caffeine increases the body's metabolism for up to four hours, which may be part of tea's weight loss attributes. Teacuppa.com also has a way to decaf your green tea.

Lastly, which green tea should I drink? Teacuppa.com has around more than 10 types of green tea. I would suggest if you like the seaweed kind feel of green tea, go for Japanese sencha tea. Many people feels that it is a seaweed taste but it is actually the lingering sweet after taste produce by the tea itself. For someone who like the chestnutty flavour of green tea. I would suggest Dragonwell tea or rather known as Xi Hu Long Jing Green Tea. For Jasmine tea lover, definately go for the Pearl Jasmine Green Tea. As for someone who love sweet but none grassy kind of green tea try Green Snail Spring Green Tea or known as Bi Luo Chun Green Tea. Gunpowder Green Tea is also another version of Bi Luo Chun tea except it is rolled into pellet form. For the rest of the green tea, I have not really tried them yet. I am looking forward for my next tasting session with Houjicha Green Tea, Huang Shan Mao Feng Green Tea and Cloud Mist Green Tea.