In 2004, scientists at the University of Newcastle studied the effects of black and green tea on Alzheimer’s disease. In laboratory studies, both teas prevented the breakdown of acetylcholine, the neurotransmitter strongly linked with memory. The teas also inhibited enzymes known as BuChE and beta-secretase. These enzymes are found in protein deposits found in the brain of Alzheimer’s patients. (7)
One study that was published in the February 2010 issue of the Journal of Agricultural and Food Chemistry investigated the effects of catechins on eye diseases and found that consuming more catechins may help protect the eyes from oxidative damage and vision loss. Scientists involved in the study found evidence that catechins can pass from the digestive tract of rodents to the tissues of their eyes and reduce oxidative stress for up to 20 hours after ingestion. (11)
But’s testing has found that even if lead is found in the leaves used in green tea bags, it doesn’t appear to be absorbed into the water. Cooperman says his team was concerned about lead content in matcha, because people consume the ground green tea leaves directly rather than in bags. However, their testing showed that among the six popular matcha brands they tested—DoMatcha, Encha Organic Matcha, Rishi Teahouse Matcha, Teavana Imperial Matcha, Kirkland Signature Green Tea and The Republic of Tea Double Green Matcha Tea—the powders were not contaminated by lead or other metals, and also did not contain pesticides. As of now, Cooperman says he doesn’t believe lead exposure is a risk in the matcha currently sold in the United States.
Day 3: As I started to make my 5th cup in 3 days, my best friend said, “Ab, I really don’t think you should be drinking so much of this stuff. Why don’t you just stick to the recommended amount?” I responded with “It’s just TEA — what’s the worst that could happen?” On day 3, I learned. I had decided to give up coffee during my 28 days, both as a way to save my sanity and excretory system and as a way to wean myself out of my coffee habit. That was really stupid. By day 3, I was experiencing a horrifying caffeine headache and a rough case of the spins. I was also literally exhausted and finally feeling the ~desired effects~ of the detox (frequent trips to the bathroom, to put it lightly), so I was dealing with an excess of that on top of my other horrible side effects. Do I blame the tea? Not even a little. I blame myself for overindulging in too much of a good thing. From there on out, I decided to follow the rules.
The Chinese scholar Lu Yu in his Cha Shung, the earliest treatise on tea, says, "When feeling hot, thirsty, depressed, suffering from headache, eye ache, fatigue of the four limbs or pains in the joints, one should only drink tea. Tea tempers the spirit, harmonizes the mind, dispels lassitude, relieves fatigue, awakens thought, prevents drowsiness and refreshes the body and mind." What else would be the most effective way to help you cope with the stress of day to day living in today's competitive world?

Another benefit of green tea it’s is lower in caffeine than most other teas, so you may be able to drink the five cups a day that lowered psychological stress in a large group of Japanese people in a recent study done at Sendai’s Tohoku University Graduate School of Medicine. The researchers didn’t identify any particular component of green tea that might have been soothing, but animal studies suggest that one compound, EGCC, had both sedative and hypnotic effects that tamp down the body’s production of stress chemicals.

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]