Tea is the second most widely consumed beverage in the world, after water. That’s because it’s so versatile: You can drink it iced or hot, and there are enough varieties of tea to suit just about any palate (there are over 1,500 types of tea—not including herbal teas).
People have been drinking tea for centuries also because of its health effects. 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, which may contribute to the prevention of cancer, osteoporosis, and cardiovascular diseases. While polyphenols are also found in abundance in fruits, vegetables, and grains—and also coffee in even higher amounts—tea is especially and uniquely rich in particular types of polyphenols called catechins (specifically, EGCG) that may be the most powerful ones of all.
The American Cancer Society explains:
EGCG may help cause certain types of cancer cells to die in much the same way that
normal cells do. This effect is important because cancer cells are different from normal cells in that they do not die when they should—they continue to grow and spread.
Although the ACS says more clinical trials are needed to support claims that green tea can prevent or treat any specific types of cancer, it notes the many laboratory studies demonstrating green tea’s protective effects against cancer cells. One study, for example, found EGCG to suppress lung cancer cell growth and another found that it inhibits breast cancer tumors. A meta-analysis of 13 studies indicates women who drink green tea have a lower risk of developing breast cancer than non-green-tea drinkers. Like most scientific research, however, there’s other conflicting results suggesting black and green tea might not contribute significantly to breast cancer risk—so you probably shouldn’t drink tea for the sole purpose of preventing cancer. That’s okay, because there are lots of other positive health associations with tea.
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.
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.”
Lower Risk of Death from All Causes
The Japanese cohort study mentioned above examined the relationship between green tea drinking and death from all causes. The researchers followed the Japanese adults (ages 40 to 79) for up to 11 years and compared those who drank less than one cup of green tea a day to those drinking five or more a day.
The results? Drinking green tea was associated with a 23% lower risk of dying from any cause in women and 12% lower risk in men.
Drinking tea can contribute to both relaxation and concentration. As Tea Class explains:
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.
As with almost all other essential elements in the leaf, L-theanine is most highly concentrated in the newest growth. A high quality loose leaf tea will contain the most L-theanine, and the very highest levels are usually found in green and white teas.