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.
And Lots, Lots More
Studies have also associated drinking green tea with lower LDL or “bad” cholesterol and reduced body fat, inhibition of the flu virus, and even less dental plaque. The book Green Tea by Nadine Taylor also cites these benefits:
- Keeping blood sugar at moderate levels
- Fighting food-borne bacteria
- Enhancing immune system function
- Promoting “friendly” bacteria in the intestines and encouraging bowel regularity
- Assisting in weight loss by blocking the breakdown of starch
- Maintaining the body’s fluid balance
- Reducing stress
No other substance on the face of the earth, including the most potent drug, can claim such wide-ranging and powerful health benefits, and all without a single side effect.
Well, some side effects have been noted with drinking too much green tea extract or supplements (not the drink itself), and pregnant women might want to avoid large amounts of green tea as well.
It’s true that tea contains caffeine, which affects everyone differently, but tea generally contains less caffeine than coffee, and the caffeine in tea is metabolized more slowly, so you can drink more cups all day long without crashing.
How to Choose and Brew Tea for Better Health Benefits
Now that we know some of the many potential ways green tea can make us healthier, let’s look at how to buy and brew it optimally.
Types of Tea: Most of the studies have focused on the health benefits of green tea, but what about black and other types of tea? Green tea has more wide-ranging and powerful benefits mainly because of its high amounts of EGCG, whereas black tea has much less because of the way the leaves are “fired” and oxidized during production. Still, black and other teas also share these important compounds and benefits.
Acne Einstein reports these mean levels of EGCG in different teas per cup, as measured by the USDA:
- Brewed green tea: 180mg
- Brewed green tea, decaffeinated: 60mg
- Brewed green tea, flavored: 45mg
- Ready-to-drink green tea: 10mg
- Brewed oolong tea: 80mg
- Brewed black tea: 20mg
The report doesn’t mention white tea, which has similar EGCG content as green tea, but might have even more health benefits than green tea because it’s even less processed. White tea, however, is rarer than green and thus less studied.
Antioxident content, however, also varies depending on the tea types, brand, and manufacturing.
Temperature and Brewing Time: Things that additionally affect the EGCG content and antioxidant potential include your water temperature and brewing time. While following general time and temperature recommendations is great for brewing a cup of tea for flavor, if you care about getting the most health-boosting benefits of a cup of tea, Acne Einstein has found:
- Brewing with hotter water results in more antioxidants in the tea
- Steeping for three to five minutes is better than less time
This goes against the usual tea rules for different types (green tea is usually brewed with water at 175 degrees F and for just a minute or so), so you might get a stronger-tasting or even bitter cup, depending on the leaves. Oolong teas, however, often do well with longer steeping time and higher temperatures.
How Many Cups to Drink a Day: Most of the studies suggest the more cups of tea you drink a day (e.g., five or more), the better, but some also found benefits with just two to three cups a day, which is what nurse practitioner and physician assistants network Advanced Healthcare recommends for patients as a “simple healthy lifestyle strategy.” (Don’t worry, tea is hydrating and doesn’t act as a diuretic.) The two-to-three cups a day recommendation fits in with most supplements’ 200 mg EGCG recommended daily serving.
All this said, it’s silly to guzzle down thermoses of tea if you don’t enjoy it. Even if you prefer stronger drinks like coffee, however, you might be surprised to learn you might just enjoy a good cup of tea too (and get the health effects as a nice side benefit).