According to the tea industry:
Much research suggests drinking tea—particularly green tea—can fight diseases and even lengthen life. This is due to tea's high concentration of antioxidants called polyphenols. While polyphenols are also found in abundance in fruits, vegetables, and grains, tea is especially and uniquely rich in particular types of polyphenols called catechins (specifically, EGCG) that may be the most powerful ones of all.
There are countless reasons to enjoy a delicious simmering up, but here are some of the most important:
Protection Against Heart Diseases and High Blood Pressure
A study of 40,530 people in Japan, where green tea is widely consumed, found drinking green tea significantly lowered the risk of dying from cardiovascular disease. (31% lower risk in women, and 22% lower risk in men.) The risk of dying from stroke was even lower: 62% lower in women and 42% lower in men. The catechins in green tea are believed to inhibit the production of free radicals in the lining of the arteries and also help prevent the formation of blood clots.
Reduced Risk of Hypertension / High Blood Pressure
Regular consumption of green or oolong tea (for at least one year) also has been shown to lower the risk of developing hypertension by 46% for those who drank up to 2.5 cups a day and 65% less for those who drank more than 2.5 cups. A review, published in the Journal of the American College of Nutrition concludes that "green tea and EGCG can be regarded as food components useful for the maintenance of cardiovascular and metabolic health."
Promotes Quiet Alertness
Drinking tea can contribute to both relaxation and concentration. L-theanine is an amino acid that occurs naturally in the Camellia Sinensis plant. In fact, unless you take an artificially manufactured dietary supplement, tea is the ONLY way to get L-theanine in your diet. This powerful amino acid boosts alpha wave activity in our brains, which promotes a state of relaxed concentration. Think "quiet alertness". The calming effects of L-theanine actually counteract the extreme highs and jitteriness that can result from excessive caffeine intake.
Burns Fat & Stabilizes Energy
Research at Tufts University indicates that EGCG in green tea, like other catechins, activates fat-burning genes in the abdomen to speed weight loss by 77 percent. In addition, it keeps energy stable by balancing blood sugar levels. EGCG also improves insulin use in the body to prevent blood sugar spikes and crashes that can result in fatigue, irritability, and cravings for unhealthy foods.