In 2009, King’s College researchers found that epicatechin may protect brain cells through mechanisms unrelated to its antioxidant ability, as epicatechin is one of the few flavonoids that can cross the blood-brain barrier. The King’s College researchers reported that somehow epicatechin protects brain cells from the negative effects of beta-amyloid plaques, although the exact mechanism of how this works is still not entirely know. (9)

Since some of the bioactive compounds in green tea are anti-viral and anti-bacterial, in much the same way as green tea can kill bacteria in your mouth, it can also inhibit bacteria and viruses in your bloodstream and throughout the rest of your body. Similarly, green tea may inhibit viral and bacterial infection via your nasal passages. All this means that green tea may help prevent colds and the flu, and furthermore seems to be able to alleviate the symptoms of colds and the flu once you are sick.
Heat or boil water, but don’t let it completely boil and become too hot, as this can destroy some of the delicate compounds found in green tea leaves. The “ideal” temperature for brewing green tea is between 160 degrees Fahrenheit to 180 degrees F (traditionally standard Chinese green teas brew at a slightly higher temperatures). Pour hot water into the teapot to steep the leaves for only about 1–3 minutes. Larger leaves need more time to steep than finer, smaller leaves. At this point you can also add any fresh herbs you plan on steeping.

Grown under shade for three weeks prior to plucking, gyokuro is one of the most exclusive varieties of tea produced in Japan.[60] The shading technique imparts a sweeter flavor, and produces a particularly rich color thanks to the higher amounts of chlorophyll in the shaded leaf. Gyokuro tea is associated with the Uji region, the first tea-growing region in Japan. It is often made using smaller-leaf cultivars of the tea plant.[61]