Americans are taking to tea in a big way, buying billionsof dollars of the brewed beverage each year. Unlike coffee, mostly absolved ofsupposed health crimes but never touted as actually being good for you, the buzzbrewing about tea is that drinking a daily cup or two may be a habit well worthforming. Could Starbucks-style tea houses be just around the corner?
Green tea has long been credited with disease-preventingproperties, but as more studies unfold, black tea is proving to hold as muchpromise as green tea in protecting against several diseases of aging. Laboratorystudies have revealed that tea?green or black?exerts even moreantioxidant power than many fruits and vegetables.
Sip to Your Heart’s Content.As evidence of how beneficial those antioxidants might be, recent researchreported in the May 28 issue of Circulation suggests that drinking teamay help reduce the risk of dying after a heart attack. Researchers from Harvard’sSchool of Public Health studied the habits of 1,900 older men and women fromaround the country who were hospitalized after a heart attack and followed themfor close to four years after they were discharged.
Those who drank the most tea?averaging two to three cupsa day?had a 44% lower death rate, from any cause, in the years following theheart attack than those who drank none. But even those with a modest tea intake?justtwo to three cups a week?had a 28% lower death rate. Both green andblack tea consumption were included but not separately identified, though mostwas probably black tea.
Researchers attribute tea’s strong showing to itsabundance of flavonoids and other antioxidants, which are thought to protect theheart in several ways. They prevent oxidative damage to low density lipoproteins(“bad” LDL-cholesterol), improve the ability of blood vessels to relaxand decrease the likelihood of life-threatening blood clots.
Researchers, including Jeffrey Blumberg, Ph.D., professorof nutrition at Tufts University in Boston, are finding it difficult to hidetheir enthusiasm.
“The heart disease studies are strong, consistent andwell designed,” says Blumberg, “with at least four large studies thatall show tea benefits the heart.” In the Rotterdam Study from TheNetherlands, for example, researchers recently found that among 4,807 men andwomen, those drinking about two cups of black tea a day had only half the riskof a first heart attack, especially a fatal one, as those who drank none.
Moreover, Blumberg recounts a clinical trial from Bostonlast year that found just four weeks of drinking three cups of black tea a dayimproved several measurements of cardiac function in people with heart disease.And population studies link green tea to lower blood pressure and lower bloodcholesterol.
Tea-Totaling for Better Bones?Caffeine has long had the reputation of contributing to brittle bones by causingthe body to excrete calcium. So researchers were surprised to find evidencesuggesting that tea, even caffeinated tea, may actually protect bones.Researchers in Britain compared 1,134 older female tea drinkers to non-teadrinkers and found that those who drank black tea?with or without milk ?had5% greater bone density.
Other investigations have shown inconsistent results, buta just-released study from Taiwan reported in the May 13 Archives of InternalMedicine found that habitual tea drinkers’those downing two or more dailycups of tea (mostly green and oolong, some black) for six to 10 years?had ahigher bone density than those drinking tea for a shorter time. This was thefirst study that examined both men and women. Moreover, the results held truefor all three kinds of tea. Researchers believe that the flavonoids, fluoride(tea is a good source) and phytoestrogens (similar to soy) in tea can becredited.
Brewing Up Cancer Prevention?Hasan Mukhtar, Ph.D., a cancer researcher at the University of Wisconsin, pointsout that tea flavonoids have been shown?mostly in studies of green tea’tooffer protection against several types of cancers. Population and animal studiessuggest that green tea (and maybe black tea) can protect against cancers of theesophagus, lung, stomach, colon, pancreas, liver and breast.
For instance, Mukhtar’s lab just published a studydemonstrating green tea can significantly inhibit the spread of prostate cancercells in mice. However, the dose was the equivalent of a daunting six cups oftea a day. As with most cancer studies, this one focused only on green tea andits active compound epigallocatechin-3-gallate (ECGC).
Color Blind: Green or Black Will Do. Don’tmake the mistake researchers made for years and underestimate black tea. Thereare fewer studies showing benefits for black tea simply because researchers gota late start studying it, initially believing green tea held the edge because ofhigher concentrations of ECGC. But black tea contains different antioxidantsthat research shows are at least as potent (see “It’s All Tea toMe,” right). Some experts predict that better methods of analyzing blacktea’s flavonoids in the future will find even more antioxidants in black teathan in green tea.
What About Iced Tea, Decaf? Sorry,but those gargantuan bottles of chilled, fancy flavored teas don’t provide thesame dose of flavonoids as a freshly brewed cup. Bottling tea and storing it forextended periods of time in glass’thus exposing it to damaging light’takesits toll on the flavonoids in ready-made iced tea.
Owing to their processing, instant powdered teas fare evenworse, providing the least amount of flavonoids. The best? Brewing your own icedtea provides as potent a dose as a cup of hot tea, assuming you drink it rightaway.
For people concerned about caffeine, a cup of brewed teahas only half the caffeine?about 50 milligrams?as a cup of brewed coffee.Decaf tea has proved to be much less protective, because much of its flavonoidsare destroyed by the decaffeinating process.
EN‘s Bottom Line. Thereis a fair consensus among researchers that tea really is good for you.Heart-healthy benefits are strong at two cups a day, though even one cup mayhelp; anti-cancer effects may require more.
Either way, more and more research is confirming that acup or two of tea each day may be healthful in the long run, not to mentionrelaxing and tasty right now. Polly, put the kettle on!
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