Until recently, most Americans and Europeans drank tea only as a tasty, mildly stimulating alternative to coffee. But that’s been changing, as the research on tea’s many health benefits becomes more widely known. The fact is, drinking a few cups of tea a day—especially green tea—reduces the risk of many serious conditions, notably heart disease and cancer.
Knowing the full extent of this herb’s healing abilities, you’ll want to make tea time more than an occasional, pleasant break from coffee … drinking tea daily could help you live a longer, healthier life.
Tea (Camellia sinensis) is native to the area where southwest China meets northwest India. The plant is a subtropical evergreen tree, but growers prune it waist-high for easier harvest. China and India each produce about one-quarter of the world’s tea crop, with most of the rest grown in Sri Lanka, Kenya, Turkey, Indonesia and Vietnam.
The leaves of the tea plant are used to make four basic types of tea—white, green, oolong and black. In most cases, after harvest, the leaves wilt and oxidize, progressively darkening as their chlorophyll breaks down and combines with oxygen in the air. The tea industry calls this process fermentation. Fermentation is a misnomer, however, because the process does not involve microorganisms—what actually occurs is oxidation.
Variations on this basic process result in the different types of tea. Black tea is wilted and fully oxidized. Oolong tea is wilted and partially oxidized. Green tea is wilted but not oxidized. White tea, made only from immature leaves and buds, is picked, steamed and dried immediately—it is not wilted nor oxidized.
Black tea accounts for an estimated 78 percent of worldwide tea consumption. Green tea accounts for about 20 percent, and white and oolong together account for only around 2 percent.
In Traditional Chinese Medicine, tea is considered a “grease cutter” that prevents harm from fatty foods, according to Efrem Korngold, O.M.D., a practitioner of Chinese medicine in San Francisco, and coauthor (with Harriet Beinfield, L.Ac.) of Between Heaven and Earth: A Guide to Chinese Medicine (Ballantine Books, 1992).
Japanese researchers wondered if this traditional belief could be scientifically verified. In the 1980s, they found potent antioxidant compounds in tea, notably epigallocatechin-3-gallate (EGCG). Antioxidants help prevent and repair the cell damage that can lead to heart disease and many cancers. Since then, dozens of additional studies have shown tea reduces risk of these diseases and helps treat them, thus validating Traditional Chinese Medicine’s claim.
The oxidation process that turns white and green teas into oolong and black teas destroys some of their EGCG.Black teas still contain significant amounts of antioxidants, which is why they reduce risk of heart disease and stroke (see below). But black teas have not shown much ability to reduce cancer risk. For cancer prevention, green tea is the way to go because it retains the most EGCG. White tea is promising too, although more studies are needed. As the least processed tea, it contains the most cancer-fighting polyphenols.
In the West, tea began its transformation from beverage into health food in 1993, when Dutch researchers published a study in the prestigious British medical journal Lancet on the effects of dietary antioxidants on risk of heart attack among residents of Zutphen, a city in the Netherlands. Men who consumed the most fruits and vegetables had the lowest heart attack risk. But tea also was protective, a finding that surprised Western scientists and sent them scurrying to the earlier Japanese research on ECGC.
Since then, many studies have shown tea—both black and green—helps prevent heart disease and the most common type of stroke. Another group of Dutch researchers followed 4,807 men for five years. Compared with those who drank no tea, men who drank one or two cups a day had 43 percent fewer heart attacks—and 70 percent fewer heart attack deaths. Similar studies by Harvard and Saudi Arabian scientists also show fewer heart attacks and heart attack deaths in regular tea drinkers. And a Dutch study shows tea also reduces risk of stroke.
If tea really helps the heart, it should exhibit a “dose-response” effect—as tea consumption increases, heart disease risk should decline. That is the case. In the Harvard study, moderate tea drinkers were 31 percent less likely to suffer heart attack. The figure for heavy tea drinkers was 39 percent. The Saudi study also showed a dose-response effect.
How do the antioxidants in tea reduce risk of heart attack and stroke? Several ways: They reduce cholesterol. They improve arterial function. And they slow the buildup of fatty, cholesterol-rich deposits on artery walls (atherosclerosis) that can lead to heart attacks and strokes.
Note: If you drink tea for heart benefits, don’t add milk. A German study suggests milk somehow neutralizes ECGC, counteracting tea’s heart-helping actions.
An occasional report shows no cancer-protective benefits for green tea, but these few negative findings are vastly outnumbered by dozens of
studies that show increasing green tea consumption decreases risk of all major cancers, including breast, ovarian, cervical, lung, stomach, prostate, colorectal, esophageal, pancreatic and malignant melanoma.
Green tea shows a clear “dose-response” effect for cancer prevention. Consider breast cancer. Australian researchers categorized green tea consumption in 2,018 Chinese women as low, moderate or high. Low tea intake reduced breast cancer risk 13 percent; moderate, 32 percent; high, 41 percent. A study at the University of Southern California showed a similar dose-response effect for reducing breast cancer risk.
Of course, some green tea drinkers still develop cancer. But if green tea has cancer-preventive benefits, then we would expect green tea drinkers to get cancer later in life than those who do not drink it. That’s precisely what Japanese researchers showed in a study correlating tea drinking in Japan with people’s age at cancer diagnosis. Compared with Japanese who drank less than three cups of green tea daily, women who drank more than 10 cups a day developed all cancers an average of almost nine years later. The figure for men was three years later.
In addition, when cancer develops, green tea minimizes its aggressiveness as well as its likelihood to recur. When Japanese researchers analyzed the breast cancers of 472 women, they found that those who drank the most green tea had the least aggressive cancers and the lowest likelihood of recurrences.
Many studies also show tea reduces risk of other serious (or potentially serious) conditions, such as diabetes, osteoporosis, dementia, rheumatoid arthritis, eczema and tooth decay.
White tea, only recently studied by researchers, appears to have more antibacterial and antiviral capabilities than green tea, according to research conducted at Pace University.
Because tea reduces the risk of so many conditions, Japanese researchers wondered if it could literally be a life saver. To find out, they followed 40,530 healthy Japanese adults for 11 years. Drinking tea decreased risk of death from all causes. Compared with drinking less than one cup a day, drinking tea regularly reduced the risk of death. And the greater the tea consumption, the greater the benefit. Drinking five or more cups a day cut death risk 12 percent in men and 23 percent in women.
So, drink up. Tea is much more than a tasty, mildly stimulating alternative to coffee. Tea, especially green tea, is a life saver.
Many people use the term “tea” to describe any herbal beverage made by steeping plant material in hot water. This works colloquially, but it is not technically accurate and can become confusing. Hot-water extracts are not teas, but “infusions.” In herbal medicine, “tea” means an infusion made with the leaves of the tea plant (Camellia sinensis).
It starts with the water. Non-chlorinated is best, according to Lori Glenn of the American Botanical Council (ABC), because chlorination interferes with tea’s flavor.
Heat the water on a stovetop or in a microwave, but don’t boil it. If the water does boil, allow it to cool a bit before pouring it over the tea leaves or bag. The optimal steeping temperature for oolong and black teas is approximately 175 degrees; for white and green teas, around 140 degrees.
Tea strength depends on the amount of leaves used and steeping time. For the typical recommendation—3 grams of leaves per cup (about a rounded teaspoon)—ABC recommends steeping green tea 2 to 3 minutes, longer for oolong and black teas. If you enjoy strong tea, keep the leaves in the water as you drink. Longer steeping will not release more antioxidants, but it will release tannins, compounds that make tea taste bitter.
3000 B.C.—According to legend, the Chinese emperor Shen Nung asked a servant for a cup of boiled water. A few leaves fell into the cup, producing the first cup of tea.
850 A.D.—Tea spreads throughout Asia. The Japanese tea ceremony, influenced by Buddhism, elevates tea preparation to an art form, emphasizing humility and simplicity.
1560—Portuguese Jesuit Father Jasper de Cruz visits China; he is the first to mention tea in Europe. The Portuguese later develop a trade route for shipping tea back to Portugal.
Ca. 1600—Dutch traders introduce tea throughout Europe, where it becomes an immediate hit with the wealthy (cost is about $100 per pound).
1618—The Chinese ambassador to Russia presents Czar Alexis with tea; the beverage (and the samovar, a large tea urn) quickly becomes popular throughout Russia.
1650-52—Tea arrives in England; increased importation reduces cost so more can afford it. In the West, Peter Stuyvesant brings tea to New Amsterdam (present day New York).
1767—England taxes American colonists on imported goods, including tea. Colonists retaliate by boycotting English tea, buying Dutch tea or making herbal “tea” instead.
1773—Samuel Adams, John Hancock and other disgruntled colonists throw hundreds of pounds of tea into Boston Harbor (the Boston Tea Party). The British send troops.
1800—In England, Anna, the Duchess of Bedford, begins serving tea with a light snack in the late afternoon—the beginning of England’s “tea time.”
1904—At the St. Louis World’s Fair, Richard Blechynden serves tea over ice during a heat wave. The new “iced tea” is the hit of the Fair.
1908—Tea merchant Thomas Sullivan packages individual cup-sized portions of tea in porous paper wrappers, the first “tea bags.”
1970s—Americans develop a taste for teas other than orange pekoe. Coffee shops like Starbucks contribute to tea’s growing popularity in the United States.
Michael Castleman has been called “one of the nation’s top health writers” (Library Journal). He specializes in herbal medicine. Visit www.MCastleman.com .
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